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  • 1
    Electronic Resource
    Electronic Resource
    Radiological “metamorphosis” in a patient with severe congenital osteogenesis imperfecta (1990)
    Springer
    European journal of pediatrics 149 (1990), S. 403-405 
    Details
    ISSN: 1432-1076
    Keywords: Osteogenesis imperfecta ; Collagen type I ; Radiology, classification ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Congenital osteogenesis imperfecta (OI) was diagnosed by ultrasound in a 31-week-old fetus, and the diagnosis confirmed after delivery by caesarean section at week 36. The baby survived the neonatal period, but failed to thrive, had recurrent respiratory infections and ultimately died at 8 months. Cultured fibroblasts synthesized both normal type I collagen and unstable type I collagen harbouring a structural defect in the α1(I) cyanogen bromide-derived peptide number 8 (CB8) region of the molecule, indicating a heterozygous dominant mutation. A+ birth, the radiological picture was that of the “thin bone”-type of congenital OI (OI type IIB/III in the Sillence classification); at the age of 12 weeks ribs and long bones had undergone a marked expansion giving a very different picture, that of the “thick bone”-type congenital OI (OI type IIA). The mechanism responsible for this change in bone structure is not known, but fractures and callus formation are unlikely to be the only factors. Caution is needed in the interpretation of radiographs of newborns with OI for prognostic or genetic purposes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02009659
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  • 2
    Electronic Resource
    Electronic Resource
    Anatomically identical short-segment Hirschsprung's disease in three male siblings (1990)
    Springer
    Pediatric surgery international 5 (1990), S. 359-360 
    Details
    ISSN: 1437-9813
    Keywords: Hirschsprung's disease ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Three male children with identical short-segment Hirschsprung's disease born to a young married couple are reported. There was no positive family history despite an extensive search. There were no associated abnormalities. Although sex-modified multifactorial inheritance, with males having a lower threshold of genes for expression of Hirschsprung's disease, is accepted, the identical expression of the disorder in the three siblings presented suggests a dominant, possibly X-linked gene with variable penetrance. Another possibility is that an identical micro-environmental factor was present prenatally resulting in all three boys having Hirschsprung's disease. This is the first report of three siblings with identical short-segment Hirschsprung's disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00177106
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  • 3
    Electronic Resource
    Electronic Resource
    Approximate analysis of variance of spatially autocorrelated regional data (1990)
    Springer
    Journal of classification 7 (1990), S. 53-75 
    Details
    ISSN: 1432-1343
    Keywords: Analysis of variance ; Choropleth map ; Ecology ; Genetics ; Geography ; Permutation test ; Spatial autocorrelation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Description / Table of Contents: Résumé Cet article présente une solution au problème de l'analyse de variance, pour certains cas où la variable à analyser est spatialement autocorr élée alors que le critère de classification représente des sous-régions connexes du territoire à l'étude. On sait que les méthodes classiques d'analyse de variance ne sont pas applicables dans ce type de situation puisque la condition d'indépendance des échantillons n'est pas respectée; l'autocorrélation positive réduit la variabilité intragroupe, si bien que la quantité relative de variabilité intergroupe s'en trouve artificiellement augmentée. Cette situation correspond en réalité à une vaste catégorie de problèmes en génétique des populations, en écologie et dans d'autres branches de la biologie, ainsi qu'en épidémiologie, en géographie, en géologie, en science économique, en science politique et en sociologie. Ce nouveau test appartient à la famille des tests par permutation. Nous calculons la somme des dispersions intragroupes et testons contre une distribution de référence obtenue en permutant les régions géographiques un grand nombre de fois sur la carte. La véritable difficulté de ce test est d'ordre algorithmique, puisqu'il n'est pas facile de permuter des régions sur une carte, de façon à ce que chaque groupe demeure connexe, et que la carte permutée occupe le même espace total que la carte d'origine. Cet article présente la théorie, les algorithmes, ainsi que des résultats obtenus par cette méthode. Un programme écrit en PASCAL est disponible.
    Notes: Abstract The classical method for analysis of variance of data divided in geographic regions is impaired if the data are spatially autocorrelated within regions, because the condition of independence of the observations is not met. Positive autocorrelation reduces within-group variability, thus artificially increasing the relative amount of among-group variance. Negative autocorrelation may produce the opposite effect. This difficulty can be viewed as a loss of an unknown number of degrees of freedom. Such problems can be found in population genetics, in ecology and in other branches of biology, as well as in economics, epidemiology, geography, geology, marketing, political science, and sociology. A computer-intensive method has been developed to overcome this problem in certain cases. It is based on the computation of pooled within-group sums of squares for sampled permutations of internally connected areas on a map. The paper presents the theory, the algorithms, and results obtained using this method. A computer program, written in PASCAL, is available.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01889703
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  • 4
    Electronic Resource
    Electronic Resource
    Common mechanisms in proboscis extension conditioning and visual learning revealed by genetic selection in honeybees (Apis mellifera capensis) (1990)
    Springer
    Journal of comparative physiology 166 (1990), S. 545-552 
    Details
    ISSN: 1432-1351
    Keywords: Honeybees ; Learning ; Classical conditioning ; Selection ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four strains of the honeybee (Apis mellifera capensis), which were selected for high (N=2) or low (N=2) performance levels in classic conditioning of olfactory and mechanosensory stimuli, were examined in two instrumental visual learning tasks. Bees were trained to coloured cardboards either at the hive entrance or at the feeding station. Positive correlations were detected between olfactory/mechanosensory conditioning and visual learning. Good and poor learners from strains selected for olfactory conditioning differed significantly in their visual learning values. These strain differences reflect genetic differences in a common learning system rather than task specific differences in sensory, motor or motivational components. Parameters that were influenced by activity of the colony (duration of stay at the feeding place, time between visits) also differed among selected strains. These effects were not due to selection. Instead, they reflect a specific genetic background produced in each strain independently of selection. The results indicate that associative learning has a genetic basis which is independent of the sensory stimuli associated with reward, the learning procedure (classical conditioning or instrumental learning) or the motor patterns used to execute the learned behavior (proboscis extension, control for flight behavior, open field orientation).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192025
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  • 5
    Electronic Resource
    Electronic Resource
    The Iowa multiplex family study of schizophrenia: Linkage analyses on chromosome 5 (1990)
    Springer
    European archives of psychiatry and clinical neuroscience 239 (1990), S. 290-292 
    Details
    ISSN: 1433-8491
    Keywords: Schizophrenia ; Linkage ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We analysed six multiplex pedigrees of schizophrenia for linkage to two DNA probes mapping to the chromosome 5q11–q13 region where linkage to a gene for schizophrenia was recently reported. Analyses were conducted using three penetrance models and considering the affected state to be schizophrenia, the schizophrenia spectrum, and all psychiatric diagnoses. All analyses gave consistently negative lod scores. Although the region was not formally excluded, no evidence for linkage was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01735053
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  • 6
    Electronic Resource
    Electronic Resource
    Genetic data and natural history of Friedreich's disease: a study of 80 Italian patients (1990)
    Springer
    Journal of neurology 237 (1990), S. 345-351 
    Details
    ISSN: 1432-1459
    Keywords: Spinocerebellar degeneration ; Friedreich's disease ; Diagnostic criteria ; Genetics ; Natural history
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical and genetic features of 80 patients with Friedreich's disease from 64 families are described. Diagnostic criteria were: no evidence of dominant inheritance, onset by the age of 20 years, progressive unremitting ataxia of limbs and gait, and absence of knee and ankle jerks. Furthermore, at least one of the following accessory signs was present: dysarthria, extensor plantar response and echocardiographic evidence of hypertrophic cardiomyopathy. Two peaks of onset age were evident at 6–9 and 12–15 years. Analysis of intrafamily variation of onset age and absence of clustering of cardiomyopathy and diabetes did not suggest genetic heterogeneity. Peripheral nerve impairment was an early finding and showed slight further progression, whereas involvement of the cerebellar and corticospinal pathways appeared later and mainly accounted for the progressive worsening of the disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315657
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  • 7
    Electronic Resource
    Electronic Resource
    The rheumatic poison: a survey of some published investigations of the immunopathogenesis of Henoch-Schönlein purpura (1990)
    Springer
    Pediatric nephrology 4 (1990), S. 533-541 
    Details
    ISSN: 1432-198X
    Keywords: Henoch-Schönlein purpura ; Pathogenesis ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Laboratory studies of the pathophysiology of Henoch-Schönlein purpura (HSP) have become more numerous in recent years with the recognition of the disease's links with the mucosal immune system in general and IgA nephropathy in particular. There are weak genetic associations with C4 null phenotypes and with HLA B35 and DR4. Studies of plasma proteins in HSP patients show an increased IgA concentration, activation of the alternative pathway of complement and consumption of factor XIII. High molecular weight (polymeric) IgA has been detected in affected individuals, which some investigators have called “immune complexes”. Many patients synthesise an IgA rheumatoid factor in the acute phase, but other autoantibodies are largely absent. In vitro studies of lymphocytes from HSP patients have demonstrated an increased number of IgA-bearing and secreting B-cells, with altered T-cell regulation of antibody synthesis. While these observations point to immune dysregulation — primarily of IgA production — as a consistent feature of acute HSP, there is as yet insufficient information available to allow a consistent theory of pathogenesis to be formulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00869841
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  • 8
    Electronic Resource
    Electronic Resource
    Genetical control and linkage relationships of Isozyme markers in sugar beet (B. vulgaris L.). 2. NADP- and NAD-specific malate dehydrogenases, 6-P-gluconate dehydrogenase, shikimate dehydrogenase, diaphorase and aconitase (1990)
    Springer
    Theoretical and applied genetics 80 (1990), S. 593-601 
    Details
    ISSN: 1432-2242
    Keywords: Beta vulgaris ; Sugar beet ; Isozymes ; Genetics ; Linkage ; Pollen fertility restorer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The NADP-specific malate dehydrogenase isozymes were controlled by multiple gene systems. Three genes coding for dimeric enzymes segregated in a dependent fashion (NADP-Mdh 1, NADP-Mdh 2, NADP-Mdh 3). A fourth gene (NADP-Mdh 4), also coded for dimers, but was not polymorphic in B. vulgaris. A fifth gene (NADP-Me 1) coded for enzymes active as monomers. Two genes were found to control the main zone of NAD-specific malate dehydrogenase: one coded for dimers (Mdh 1), while a second (Mdh 2) was not polymorphic in the assessions studied. 6-P-Gluconate dehydrogenase was not polymorphic in B. vulgaris; the two types detected on SGE1 electrophoresis were due to developmental expression of the different systems. No genetical segregations could be detected in progeny of crosses of the distinct phenotypes. A shikimate dehydrogenase gene (Skdh 1) that coded for monomers was identified. The diaphorase system was rather complex, but one gene (Dia 1) coding for monomeric enzymes could be identified. Aconitase was found to be controlled by two independent genes (Aco 1, Aco 2), both polymorphic and coding for proteins active as monomers. Tight linkage was found between the genes NADP-Mdh 1, NADP-Mdh 2 and NADP-Mdh 3. Linkage was also found between a pollen fertility restorer (Z) and the Mdh 1 gene. The identification of linkage with Aco 1 needs further investigation. R segregated independently from Mdh 1, Aco 1 and Dia 1. Independent segregations were scored for isozyme genes Pgm 2, Icd 1, Ak 1, Gpi 1, Aco 1 and Dia 1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224217
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  • 9
    Electronic Resource
    Electronic Resource
    The Rj4 allele in soybean represses nodulation by chlorosis-inducing bradyrhizobia classified as DNA homology group II by antibiotic resistance profiles (1990)
    Springer
    Theoretical and applied genetics 80 (1990), S. 33-37 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Symbiosis ; Nitrogen fixation ; Coevolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To determine the relationship between nodulation restriction by the Rj4 allele of soybean, rhizobitoxine-induced chlorosis, and taxonomic grouping of bradyrhizobia, 119 bradyrhizobial isolates were tested in Leonard jar culture for nodulation response and chlorosis induction. In addition to strain USDA 61, the strain originally reported as defining the Rj4 response, eight other isolates (i.e., USDA 62, 83, 94, 238, 252, 259, 260, and 340) were discovered to elicit the nodulation interdiction of the Rj4 allele. Only 16% of all the bradyrhizobial strains tested induced chlorosis, but seven of the nine strains (78%) interdicted by the Rj4 allele were chlorosis-inducing strains. Furthermore, in tests for antibiotic resistance profile, eight of the nine interdicted strains (89%) were classed in DNA homology group II. This evidence suggests that the Rj4 allele has a positive value to the host plant in shielding it from nodulation by certain chlorosis-inducing bradyrhizobia of a DNA homology group with impaired efficiency of nitrogen fixation with soybean.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224012
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  • 10
    Electronic Resource
    Electronic Resource
    The genetics of two homothallic species of the Mucoraceae (1990)
    Springer
    Sexual plant reproduction 3 (1990), S. 31-34 
    Details
    ISSN: 1432-2145
    Keywords: Mucoraceae ; Zygomycetes ; Homothallic ; Genetics ; Nutritional complementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Auxotrophic strains of Mucor genevensis and Zygorhynchus exponens were crossed and the resulting zygospores germinated. The presence of a true sexual cycle in both species was demonstrated by the recovery of recombinant genotypes. Expected Mendelian ratios were not realized, however. The presence of selfed zygospores among those isolated makes this observation understandable. It was possible to demonstrate nutritional complementation when young mating mycelium was transferred to minimal medium and forced heterokaryons were recovered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189949
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  • 11
    Electronic Resource
    Electronic Resource
    The importance of sampling scale in the assessment of intraspecific life-history differences in plains killifish, Fundulus zebrinus, populations (Pisces: Cyprinodontidae) (1990)
    Springer
    Environmental biology of fishes 29 (1990), S. 263-275 
    Details
    ISSN: 1573-5133
    Keywords: Demography ; Genetics ; Geographic variation ; Stochasticity ; Fluctuating environments ; Allele frequencies ; River ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The purpose of this study was to determine the effects of unpredictable environmental fluctuations on the demographic and genetic structure of Fundulus zebrinus populations. Collections of F. zebrinus were taken from three rivers in the Arkansas River basin: the Arkansas, Chikaskia, and Ninnescah. Fish were sampled from three sites on each river on nine collection dates throughout 1984 and 1985. Totals of 2100 fish and 6000 fish were included in electrophoretic and demographic analyses, respectively. The results of the study indicate that within a limited geographic region (i.e. within rivers) spatial differences and temporal changes in both demographic and genetic population characteristics occur frequently and are primarily stochastic. However, on a larger spatial scale (i.e. across rivers), general trends emerge for demographic and especially for genetic population characteristics. These results illustrate the importance of sampling scale for conclusions of life-history evolution in fluctuating environments. In addition, it was found that regulation of Fundulus zebrinus populations includes an important density-independent component. Stochastic demographic differences across space and changes through time and spatially and temporally heterogeneous allele frequencies, are both indicative of density-independent regulation. Variation in population parameters, both demographic and genetic, was observed between populations sampled from each river. These population differences were attributed to differences between the rivers themselves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001184
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  • 12
    Electronic Resource
    Electronic Resource
    Genetic variability associated with hovering time inTabanus nigrovittatus Macquart (Diptera: Tabanidae) (1990)
    Springer
    Journal of insect behavior 3 (1990), S. 579-587 
    Details
    ISSN: 1572-8889
    Keywords: Genetics ; polymorphism ; reproductive isolation ; hovering behavior ; Tabanus nigrovittatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The salt marsh horse fly, Tabanus nigrovittatusMacquart, exhibits two nonoverlapping daily periods of hovering and mating activity, which are correlated with different environmental temperatures. Allelic and genotypic frequencies of hovering males collected during the two periods were compared by electrophoresis of three polymorphic enzyme loci. Approximately 26% of early-hovering males possessed a Pgmallozyme that was absent in our sample of late-hovering males. However, based on other allozyme loci, we found no evidence for reproductive isolation between early and late hoverers. All the genetic data are consistent with the hypothesis that the Pgmpolymorphism is associated with behaviorally and physiologically distinct groups of males that, by all other criteria, form a single Mendelian population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01052329
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  • 13
    Electronic Resource
    Electronic Resource
    Genetic aspects of interpopulational differences in pheromone blend of cabbage looper moth,Trichoplusia ni (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2935-2946 
    Details
    ISSN: 1573-1561
    Keywords: Genetics ; sex pheromone ; Lepidoptera ; Noctuidae ; Trichoplusia ni ; cabbage looper moth ; reproductive isolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The genetic basis of interpopulational differences in the pheromone blend emitted by the cabbage looper moth,Trichoplusia ni (Hübner), was examined by crossing individuals from a field-derived population (P1) with individuals from a long-maintained laboratory colony (P2). These colonies differed in the emission rate and relative proportions of four of the five known minor pheromone components, but not in the emission rate of the major component, (Z)-7-dodecenyl acetate (Z7-12∶Ac). These differences in pheromone blend were quantitatively small but biologically significant, because in the field, males responded preferentially to traps baited with a pheromone blend that is similar to that emitted by P1 females relative to a blend similar to that emitted by P2 females. In initial crosses, variation in the quantity and quality of pheromone blends among families of P1, P2, and F1 hybrid females was examined. In F1 females the relative proportions (quantity relative to the major component) of (Z)-5-dodecenyl acetate (Z5-12∶Ac) and (Z)-7-tetradecenyl acetate (Z7-14∶Ac) were intermediate to parental lines. In a second more extensive set of crosses, analyses included P1, P2, F1, F2, and selected backcrosses. The relative proportion of Z5-12∶Ac, Z7-14∶Ac, and Z9-14∶Ac emitted by F1 females were intermediate to parental lines. The frequency distributions of relative proportions of these components emitted by females were not consistent with those expected under a single autosomal or sex-linked gene hypothesis, suggesting that more than one gene is involved in the quantitative differences in the pheromone blend.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00979485
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  • 14
    Electronic Resource
    Electronic Resource
    Are genes units of inheritance? (1990)
    Springer
    Biology and philosophy 5 (1990), S. 349-371 
    Details
    ISSN: 1572-8404
    Keywords: Genetics ; gene structure ; hereditary unit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Definitions of the term ‘gene’ typically superimpose molecular genetics onto Mendelism. What emerges are persistent attempts to regard the gene as a ‘unit’ of structure and/or function, language that creates multiple meanings for the term and fails to acknowledge the diversity of gene architecture. I argue that coherence at the molecular level requires abandonment of the classical unit concept and recognition that a gene is constructed from an assemblage of domains. Hence, a domain set (1) conforms more closely to empirical evidence for genetic organization of DNA regions capable of transcription and (2) has ontological properties lacking in the traditional unit definition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00165258
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  • 15
    Electronic Resource
    Electronic Resource
    Masthead (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110101
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  • 16
    Electronic Resource
    Electronic Resource
    Introduction: The expression and function of specific genes in early embryonic development (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 1-1 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110102
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  • 17
    Electronic Resource
    Electronic Resource
    Developmental expression of regionally specific cell surface antigens in the Xenopus gastrula (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 110-122 
    Details
    ISSN: 0192-253X
    Keywords: Embryonic cell surface ; glycoconjugates ; monoclonal antibodies ; developmental expression of glycoconjugates ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Molecular markers for specific cell lineages would be useful in studies of cellular differentiation. To isolate such markers monoclonal antibodies (MoABs) were raised against plasma membranes isolated from gastrulating Xenopus embryos. Those antibodies that recognized subsets of cells within the embryo were selected by indirect immunofluorescence. The analysis of eight such MoAbs is presented. Western blot analysis showed that all but one MoAb recognized a complex pattern of glycoconjugates associated with glycoproteins. All the antigens recognized by the MoAbs were maternal in origin and displayed similar spatial patterns of pregastrular expression. This pattern of immunoreactivity at the apical surface was inherited passively during cleavage by the resulting superficial blastomeres suggesting that ectodermal specific markers of maternal origin are pre-localized to the cortical ooplasm in mature oocytes. We suggest that these maternal components may be specific glycosyl transferases. Three different patterns of expression were observed during gastrulation as exemplified by MoAbs 1F10C1, 3A4D1, and 6F10B6. MoAb 6F10B6 was specific for both neural and non-neural epithelium. MoAb 3A4D1 was specific for non-neural epidermis. MoAb 1F10C1 appeared to recognize a protein epitope on an extracellular component expressed by the superificial and involuting epithelial cells. The pattern of expression for the 1F10C1 antigen suggests that it may play a role in facilitating the movement of the involuting cells during gastrulation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110112
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  • 18
    Electronic Resource
    Electronic Resource
    Genetic alteration of normal aging processes is responsible for extended longevity in Drosophila (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 141-148 
    Details
    ISSN: 0192-253X
    Keywords: Aging ; longevity ; genes and aging ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The first step in a genetic analysis of aging is to identify and characterize the genetic mutants and their controls that will be used. Such mutants or strains are initially identified by their effect on the life span. Yet many genetic interventions are known to have some effect on the life span without necessarily affecting the aging process. It is therefore necessary to prove that one is actually dealing with an aging mutant before one draws strong inferences from the data. Casarett's rules provide an operational test for doing so, relying as they do on the comparison of aging biomarkers in the experimental and reference strains. We show that our previously described genetically based long-lived NDC-L strain and its normal-lived NDC-R control strain differ only in the chronological age of expression of two behavioral and three physiological functional age biomarkers. They do not differ in the sequence or the physiological age of expression of these biomarkers. These two strains comply with the Casarett rules and thereby comprise a valid tool with which to conduct a comparative genetic analysis of aging. The implications of the available data are discussed, including the possibility that aging in these strains of Drosophila melanogaster may be the result of a multiphasic developmental process.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110204
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  • 19
    Electronic Resource
    Electronic Resource
    Butyrate induces expression of transfected human fetal and endogenous mouse embryonic globin genes in GM 979 erythroleukemia cells (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 168-174 
    Details
    ISSN: 0192-253X
    Keywords: Human fetal globin gene ; hemoglobin switching ; mouse erythroleukemia cells ; erythroid differentiation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have analyzed the expression of endogenous murine genes and of transfected human fetal Aγ globin gene in GM 979, a mouse erythroleukemia line which produces adult as well as embryonic globins. Optimal induction of the endogenous murine adult globin genes was obtained with DMSO or HMBA while the ∊y and βh1 embryonic genes were preferentially induced by butyrate. Similarly, the transferred human Aγ globin gene was preferentially induced by butyrate. These results as well as previous observations in vivo or in erythroid cell cultures suggest that butyrate preferentially induces the expression of fetal globin genes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110207
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  • 20
    Electronic Resource
    Electronic Resource
    Masthead (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110301
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  • 21
    Electronic Resource
    Electronic Resource
    Regulation of nuclear genes encoding chloroplast proteins in transgenic plants (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 197-204 
    Details
    ISSN: 0192-253X
    Keywords: Light-regulated genes ; transgenic plants ; enhancer ; silencer ; regulatory elements ; trans-acting factors ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Transgenic plants have been particularly useful in studying nuclear genes encoding for photosynthetic functions. The expression of these genes and their chimeric constructs in transgenic plants faithfully mimics their natural counterparts. The use of sensitive chimeric reporter genes has enabled localizing the activity of genes encoding photosynthetic proteins to individual cells. Cab and rbcS transgenes have been shown to retain sensitivity to light quality, which is modulated by phytochrome. Conditional light activation under the influence of a circadian rhythm has been shown for Cab transgenes. Transgenic plants containing truncated promoters have helped delineate cis-regulatory positive and negative elements involved in light-mediated transcriptional induction and tissue specificity.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110305
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    Masthead (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110401
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    Bacterial and firefly luciferase genes in transgenic plants: Advantages and disadvantages of a reporter gene (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 224-232 
    Details
    ISSN: 0192-253X
    Keywords: lux ; luc reporter genes ; light emission ; gene expression ; single photon imaging in vivo ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genes encoding light-emitting luciferase were recently isolated from luminous marine bacteria and fireflies. Expression of luciferase genes in diverse organisms is a unique way for studying gene expression by simple and sensitive measurement of light. Recent advances in application of luciferase reporter genes are reviewed and documented by examples of in vivo visualization of their expression in transgenic plants.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110308
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    Dosage compensation in Drosophila melanogaster male and female embryos generated by segregation distortion of the sex chromosomes (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 249-253 
    Details
    ISSN: 0192-253X
    Keywords: Drosophila ; embryonic development ; sex differentiation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We report the first practical application of a genetic scheme devised for the purpose of obtaining large quantities of embryos of a specific sex. The scheme, which is based on the meiotic drive system Segregation Distorter, results in the production of populations of zygotes that are almost exclusively of one sex. We have used this scheme to determine that the steady-state levels of transcripts of X-linked genes are the same in early male and female embryos, establishing that these genes are dosage compensated.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110402
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    Heat shock causes the collapse of the intermediate filament cytoskeleton in Drosophila embryos (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 270-279 
    Details
    ISSN: 0192-253X
    Keywords: Phenocopy ; developmental arrest ; heat lability ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Heat shock has a dramatic effect on the organization of the cytoplasm, causing the intermediate filament cytoskeleton to aggregate of the nucleus. This has previously been shown in cultured Drosophila and mammalian cells. In this paper we analyze the heat lability of the intermediate filament cytoskeleton in early Drosophila embryos by indirect immunofluorescence. At all stages of embryogenesis tested, the intermediatefilamentcytoskeleton, which is maternally provided, is severely disturbed by 30 min heat shock at 37°C. After the nuclei have migrated to the subcortical cytoplasm, it collapses around them. Nuclei in all heat-shocked embryos are considerably enlarged and become displaced. Embryos before cellular blastoderm stage, in which heat shock protein synthesis is not inducible, are irreversibly arrested in development by heat shock. Embryos at or after cellular blastoderm, which do synthesize heat shock proteins in response to stress, are also immediately arrested in development but continue development when returned to 25°C. We discuss the possibility that cytoplasmic events such as the intermediate filament cytoskeleton rearrangement may be involved in heat shock-mediated phenocopy induction.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110405
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    Arabidopsis: Sensitivity of growth to high temperature (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 294-298 
    Details
    ISSN: 0192-253X
    Keywords: Soybean ; Heat sensitive genotype ; heat shock proteins ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Arabidopsis thaliana seedlings as measured by an electrolyte leakage assay, have been found to be extremely sensitive to high temperature stress as compared to a high temperature tolerant variety (Tracy) of soybean. Over 50% ion leakage occurred in Arabidopsis leaves during a 15-minute exposure to 50°C, indicating a heat killing time of less than 15 minutes. In contrast, the heat killing time for soybean at 50°C was over five times longer. When soybean or Arabidopsis seedlings in culture plates were exposed to 37°C for 2 hours and then returned to 23°C, they suffered no apparent short-term or long-term damage. Soybean seedlings given a 42°C, treatment for 2 hours also showed no damage. Arabidopsis seedlings after a 42°C treatment for 2 hours showed no apparent immediate damage, but 48 hours after return to 23°C severe damage symptoms were visible and after 96 hours all the seedlings were dead. Both soybean and Arabidopsis seedlings synthesize heat shock proteins (hsps) when exposed to 42°C for 2 hours. The hsps synthesized are of similar molecular weights, although the relative abundances of the different size classes are very different in the two plants. Even though hsps are produced in Arabidopsis seedlings after a 2 hour exposure to 42°C their presence is not sufficient for the seedlings to recover from the effects of rhe heat shock when returned to 23°C. Our results show that Arabidopsis has a heat sensitive genotype. This along with its other characteristics should make it a good model system in which to assay in transgenic plants, the functions of homologous and heterologous genes that might be candidates for determining heat tolerance in plants.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110408
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    Introduction (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 175-175 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110302
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    Actin-Associated proteins in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 328-332 
    Details
    ISSN: 0192-253X
    Keywords: Cellular slime molds ; cytoskeleton ; actin-binding proteins ; review ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cellular slime mold Dictyostelium discoideum is becoming the premier system for the explication of the biochemical and cellular events that occur during motile processes. Proteins associated with the actin cytoskeleton, in particular, appear to play key roles in cellular responses to many external stimuli. This review summarizes our present understanding of the actin-associated proteins in Dictyostelium, including their in vitro activities and their structural and/or functional analogues in mammalian cells.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110503
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    Gametic imprinting and the manifestation of the fused gene in the house mouse (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 263-269 
    Details
    ISSN: 0192-253X
    Keywords: Penetrance ; reciprocal effects ; suppressor genes ; developmental cycle in mammals ; initialization ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The phenomenon of gametic imprinting in mammals has raised developmentally relevant questions concerning the manifestation and inheritance of genes with variable penetrance. The dominant fused (Fu) gene located on chromosome 17 is one of the few good cases demonstrating the phenomenon in mice. The Fu mutation has a maternal effect.We have previously shown that the † 12 haplotype significantly lowers the penetrance of Fuin ♀ ♀ Fu/†12 offspring. Results of recipiocal matings of the heterozygotes for Fu indicated that the Fu of maternal origin has a lowered level of penetrance. The dominant suppressors locotad outside chromosome 17, in contrast to †12 residing in it, had stronger effects on the manifestation of Fu, decreasing its penetrance to 8-17%. Experimental evidence is presented that the pathway via which Fu passes to the zygote nucleus during gametogenesis through successive generations has a marked effect on its penetrance. Based on this evidence, patterns of genetic imprinting are described. A survey of genetic imprinting allowed us to distinguish two developmental phases, gametic and zygotic. The hypothesis for the gametic phase of the development of multicellular organisms suggests that it proceeds from initialization, a process thought to ensure the freeing of chromosomes from redundant epigenetic information and their preparation for the consecutive developmental cycle.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110404
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    Regulatory gene interactions controlling discoidin lectin expression in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 418-424 
    Details
    ISSN: 0192-253X
    Keywords: Transcription ; development ; cAMP ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genetic studies have revealed a network of three unlinked regulatory genes that control the developmental expression of the family of endogenous lectins in Dictyostelium discoideum. Mutations in the disA and disB loci have a null phenotype and do not express the discoidin I or II lectins. The third mutation, drsA, is a second-site suppressor of the disB mutation, which restores expression of all lectin species. Cells carrying this mutation express the discoidin lectins during growth, which is in contrast to wild-type cells in which lectin synthesis is developmentally regulated. In addition to this basic level of genetic control, the conditions of growth dramatically influence the patterns of discoidin expression. Growth-phase wild-type cells do not express lectin if the cells are grown on plates in association with bacteria. However, wild-type cells growing in bacterial suspensions express high levels of lectin during growth. Synthesis of the discoidin lectins in growing cells is sensitive to the levels of extracellular cyclic adenosine monophosphate (cAMP) and folic acid. These results suggest that the drsA mutation renders cells insensitive to cAMP and/or folate and thus allows expression of lectin during growth.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110515
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    Glycoproteins in Dictyostelium (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 453-453 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110521
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    Characterization of IMP-E3, A gene active during imaginal disc morphogenesis in Drosophila melanogaster (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 299-309 
    Details
    ISSN: 0192-253X
    Keywords: Ecdysone ; gene regulation ; imaginal discs ; morphogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The steroid hormone 20-hydroxyecdysone (20-HE) induces imcainol discs to form adult appendages in Drosophila. We have isolated a set of six ecdysone-responsive genes that apparently encode disc cell-surface or secreted proteins. Transcripts from one of these genes, IMP-E3, accumulate rapidly within 1-2 h in response to hormone. Developmentally,IMP-E3 transcripts reach maximum levels during the first stages of metamorphosis (white prepupae, WPP) and are primarily limited to imaginal tissues. Transcripts are also present during embryogenesis (0-3 h and 12-18 h). Two different-sized transcripts (1.2 and 1.4 kb) result from differential polyadenylation, with the larger transcript predominating in WPP. The conceptual IMP-E3 protein contains a signal peptide, an RGD sequence, and a potential glycosylphosphatidylinositol anchor. We speculate that the protein provides a transient cue important for imaginal disc morphogenesis.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110409
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    In situ hybridization studies on murine catalase mRNA expression during embryonic development (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 318-325 
    Details
    ISSN: 0192-253X
    Keywords: Mice ; housekeeping genes ; liver ; tissue specificity ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In situ hybridization using nucleic acid probes was used to detect cell- and tissue-specific transcript(s) of embryonic genes during development and differentiation. This highly sensitive technique has the potential to provide valuable information on the regulation of low-abundance housekeeping genes during development. We have determined the experimental conditions required to detect the catalase message in adult mouse liver. Catalase effects the breakdown of H2O2 to O2 and H2O and offers protection against the toxic effects of oxygen radicals. We used a cloned 550 bp BamHI-Pstl fragment from a mouse catalase cDNA (pMCT-1) to generate 35S-labeled sense and antisense riboprobes. The experimental conditions used were sensitive enough to quantitate the abundance of silver grains generated by the antisense riboprobe on the adult liver, a tissue known to be positive for this message. The hybridization protocol was applied to serial sections of 13- and 18-day-old mouse embryos. The results suggest that the catalase expression in the liver and brain begins with somite formation and increases with development and differentiation. On the other hand, this message appears to be absent in mesenchyme, particularly in day 13 embryos. The message in positive tissues appears evenly distributed throughout the cell. The observed expression of the catalase message in the adult liver is approximately six times that in the embryonic liver. It is compatible with the enzyme activity results and emphasizes the sensitivity of the in situ hybridization method (over northern blot, etc.) used in this study.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110411
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    Intracellular vesicle movement, cAMP and myosin II in Dictyostelium (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 341-353 
    Details
    ISSN: 0192-253X
    Keywords: Vesicle movement ; myosin II ; cAMP ; Dictyostelium ; actin ; computer-assisted motion analysis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Dictyostelium amoebae were analyzed before and after rapid addition of 10-6 M cAMP for cellular motility, dynamic shape changes, and intracellular particle movement. Before cAMP addition, amoebae moved in a persistent anterior fashion and were elongate with F-actin localized predominantly in the anterior pseudopod. Intracellular particles moved rapidly and anteriorly. Within seconds after 10-6 M cAMP addition, cells stopped translocating, pseudopod formation ceased, intra-cellular particle movement was depressed, and F-actin was lost from the pseudopod and concomitantly relocalized in the cell cortex After 10 seconds, expansion zones reappeared but were small and no longer anteriorly localized. Vesicle movement partially rebounded but was no longer anteriorly directed. The myosin II null mutant HS2215 exhibited both depressed cellular translocation and vesicle movement. The addition of cAMP to HS2215 cells did not result in any detectable change in the random, depressed movement of particles. The results with HS2215 suggest that myosin II is essential for (1) rapid cellular translocation, (2) cellular polarity, (3) rapid particle movement, (4) anteriorly directed particle movement, and (5) the cAMP response. Electron micrographs suggest that at least half of the particles examined in this study contain in turn smaller membrane bound vesicles or multilameilar membrane bodies. The possible role of these vesicles is discussed.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110505
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    Heterodimeric capping proteins constitute a highly conserved group of actin-binding proteins (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 369-376 
    Details
    ISSN: 0192-253X
    Keywords: Cytoskeleton ; capping proteins ; genamic structure ; Dictyostelium ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The two subunits of the het-erodimeric protein cop32/34, an actin-binding protein, are encoded by separate single-copy genes. We have established the genomic structure of both genes. A sequence comparison of cap32/34 with capZ from chicken skeletal muscle and two partially known sequences from Saccharomyces cerevisiae and Xenopus laevis show that heterodimeric capping proteins belong to a highly conserved group of actin-binding proteins. This conclusion is supported by the cross-reaction of polyclonal antibodies against cap32 and cap34 with proteins from lower and higher eukaryotes. In addition, a system is presented that allows the expression of truncated cap34 polypeptides under the control of the cap34 promoter.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110508
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    Establishment of conditions for the transformation of nonaxenic Dictyostelium strains (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 391-395 
    Details
    ISSN: 0192-253X
    Keywords: Lipofectin ; slime mould ; transformation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have studied the transient expression, in Dictyostelium cells growing on a bacterial food source, of a construct containing the coding region of the firefly luciferase gene inserted downstream of a Dictyosteliumactin promoter. The fusion gene is not detectably expressed when DNA is introduced by calcium phosphate precipitation or by electroporation, but it is expressed when introduced using cationic liposomes (lipofectin). Using this latter procedure, we are able to transform cells with a G418 resistance vector and select stable, drug-resistant transformants at a relatively low, but workable, efficiency. This technique will allow molecular genetics to be applied to the many important nonaxenic Dictyostelium strains.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110511
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    Introduction to the pattern formation section (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 425-426 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110516
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    Temporal and spatial expression of a cytoskeletal actin gene in the ascidian Styela clava (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 2-14 
    Details
    ISSN: 0192-253X
    Keywords: Gene expression ; mRNA localization ; ascidian embryos ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have cloned and characterized the temporal and spatial expression of ScCAl5, a cDNA clone encoding an actin gene in the ascidian Styela clava. The partial nucleotide and derived amino acid sequences of this single- copy gene suggest that it is a cytoskeletal actin. Northern analysis shows that ScCAl5 corresponds to a 1.8-kb mRNA that is transcribed during oogenesis, during embryonic development, and in the adult. In situ hybridization shows that maternal ScCA15 mRNA is distributed uniformly in the cyto- plasm of the oocyte and unfertilized egg. During the period of ooplasmic segregation following fertilization, however, ScCAl5 mRNA appears to be translocated into the ectoplasm, a specialized cytoplasmic region of the egg. During the early cleavages, the ectoplasmic transcripts are partitioned to ectodermal cells in the animal hemisphere, which are precursors of the epidermis and nervous system of the larva. Maternal ScCA15 mRNA is degraded just before gastrulation and replaced by zygotic transcripts which begin to accumulate between the neurula and mid-tailbud stages. Zygotic ScCAl5 mRNA accumulates primarily in the epidermal and neural cells, although lower levels of these transcripts may also be present in tail muscle cells. These results show that two mechanisms are used to concentrate ScCA15mRNA in the ectodermal cells during development: (1) localization and differential segregation of maternal transcripts and (2) specific expression of the ScCA15 gene. ScCAl5 mRNA is detected by in situ hybridization in the testes, ovaries, alimentary tract, and endostyle of adults. In the testes, ScCA15 mRNA is present in developing sperm, whereas in the ovary, these transcripts are present in the germinal epithelium and developing oocytes. In the alimentary tract, ScCAl5 mRNA is confined to the gastric epithelium of the esophagus, stomach, and intestine. Since the ScCA15 gene is expressed in embryonic and adult tissues that are undergoing rapid cell division, this actin is likely to function in some aspect of cell proliferation.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110103
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    Expression of NA, K-ATpase α and β subunit genes during preimplantation development of the mouse (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 41-48 
    Details
    ISSN: 0192-253X
    Keywords: Embryogenesis ; cavitation ; Na ; K-ATPase ; mRNA ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: NaK-ATPase is a plasma membrane enzyme that plays a critical role in eutherian blastocoel formation (cavitation) by pumping Na+ into the extracellular space enclosed by the trophectoderm. Previous experiments with the mouse had shown that the α (catalytic) subunit of the enzyme becomes detectable by immunocyto-chemistry in the late morula, just prior to the onset of cavitation. In the present study we have used cDNAs corresponding to three mRNA isoforms of the α subunit and a β subunit to determine which genes are expressed during preimplantation development and to explore the timing of their expression. Of the three α subunit cDNAs tested by Northern blot hybridization with blastocyst RNA, only α1 produced a hybridization signal, recognizing a single mRNA about 4 kb in length. This mRNA is relatively abundant in zygotes but barely detectable by the 2-cell stage and then accumulates steadily thereafter to reach its preimplantation maximum in blastocysts. The β1 cDNA detected mRNA of about 2.6-2.8 kb. This mRNA is present in zygotes but could not be detected in 2-, 4-, or 8- cell stages; it is present at a low level in late morulae and is abundant in blastocysts. The temporal profile of accumulation of β1 mRNA thus matches more closely than does α1 the timing of appearance of the catalytic subunit. This suggests that the β subunit may regulate production of the holoenzyme and hence the timing of cavitation.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110106
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    Characterization and expression of two sea urchin homeobox gene sequences (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 77-87 
    Details
    ISSN: 0192-253X
    Keywords: Divergent homeobox ; embryonic transcription ; homeobox evolution ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We describe two homeobox sequences, TgHbox5 and TgHboxó, isolated from the Hawaiian sea urchin Tripneustes gratilla using a Drosophila Sex combs reduced probe. Sequence analysis shows that the encoded TgHbox5 home-odomain shares only 30-52% amino acid identity with homeodomains encoded by previously characterized genes, establishing that it is a divergent homeobox that is not in any known class of homeoboxes. TgHbox5 is expressed in the embryo as two major developmentally regulated transcripts. one at 5.0 kilobase (kb) appearing by blastula stage and the other at 2.7 kb appearing at pluteus stage. Multiple transcripts from TgHbox5 are present at a much lower level in adult tissues and are predominantly expressed in small and large intestines. The TgHbox6 homeobox is an Antennapedia-class homeobox, which appears not to be expressed during embryogenesis but produces abundant 3.6 and 3.2 kb transcripts in the six adult tissues examined.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110109
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    Different requirements for l(1)giant in two embryonic domains of Drosophila melanogaster (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 88-96 
    Details
    ISSN: 0192-253X
    Keywords: Pattern formation ; segmentation ; gap genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: L(1)giant is a zygotic lethal mutation which affects the embryonic development of both the labial/thoracic segments and a subset of posterior abdominal segments. Using antibodies specific for proteins encoded by several Drosophila genes to identify the compartmental origin of the defects, we show that the requirement of giant activity is different in these two embryonic domains. Anteriorly, the posterior compartment of the labial segment is missing at the blastoderm stage. Posteriorly, cells are specifically deleted by cell death within the anterior compartments of abdominal segments 5-7 during germ band elongation. In mature embryos, posterior compartment structures of the peripheral nervous system of A5-7 are fused. In addition to a different pattern of defect in the two parts of the embryo, the kind of action appears different. Anteriorly, giant resembles a gap mutation in that a particular region is missing from the blastoderm fate map, whereas in the abdominal domain, giant affects the development of anterior compartment-specific structures.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110110
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    Cis-acting sequences and trans-acting factors required for constitutive expression of a microinjected HSP70 gene after the midblastula transition of Xenopus laevis embryogenesis (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 97-109 
    Details
    ISSN: 0192-253X
    Keywords: Heat shock promoters ; HSP70-CAT ; microinjection ; linker-scanner mutations ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Microinjected human HSP70 promoter-chloramphenicol acetyl transferase (CAT) chimeric genes are constitutively expressed immediately after the midblastula transition of Xenopus embryogenesis. Analysis of a series of 5′-deletion mutants in the HSP70 promoter revealed that sequences within 74 bases of the transcriptional start site were sufficient for strong basal activity. We investigated the role of specific sequences in the basal promoter by injecting HSP70-CAT vectors containing linker-scanner mutations in the basal elements (CCAAT, purine-rich element, GC-element, ATF/AP1, and 1ATA). Our data reveal that deletion of any of these cis-acting elements in the basal promoter prevents expression after the midblastula stage of development. Furthermore, we have identified specific binding activities in embryonic nuclear extracts that complex with basal promoter elements (CCAAT, ATF, and GC) of the heterologous HSP70 promoter. These trans-acting factors are detectable in nuclear extracts of early blastula embryos, and their respective binding activity increases dramatically after the midblastula transition. The expression of the human HSP70 gene after the midblastula transition of Xenopus embryogenesis requires an array of cisacting elements, which interact with specific Xenopus transcription factors.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110111
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    Endoreduplication of nuclear DNA in the developing maize endosperm (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 125-132 
    Details
    ISSN: 0192-253X
    Keywords: Flow cytometry ; polytenization ; C value ; fluorescence ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Multiparametric flow cytometry was used to analyze the development of the endosperm in Zea mays L. during the period from 8 to 20 days after pollination (dap). Nuclear size, DNA content per nucleus, and frequencies of nuclei with varying properties were measured in preparations that included all of the endosperm nuclei of single kernels of the inbred strain Al88. Characteristics of nuclear populations from different kernels on the same ear showed minimal variation. The dynamic changes of non-mitotic cells involved in endosperm development consisted of alternating periods of DNA replication with non-replication. Seven rounds of DNA replication had occurred in some nuclei in the later developmental stages with the rate averaging approximately one round per 24-hour period. Analysis of the DNA levels in the nuclei showed an exact doubling pattern indicating an endoreduplication process, that is, replication of the entire genome during each round. The loosely organized polytenization of the chromatin occurred to varying extents among the nuclei within an endosperm. A weak positive correlation existed between DNA content and size of nuclei suggesting that DNA increases and nuclear growth may not be highly coordinated in this tissue. Increased proportions of the larger nuclei occurred in the later stages of endosperm development. Considering the entire endosperm, the average DNA content per nucleus at the 15-dap peak level was approximately 12.8 C constituting a 2.7-fold overall increase from 8 dap.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110202
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    Expression of soybean lectin gene deletions in tobacco (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 160-167 
    Details
    ISSN: 0192-253X
    Keywords: Flanking sequences ; insertion events ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A series of constructs containing the developmentally regulated soybean lectin gene (Le1) were used to transform tobacco plants in order to assess developmental and quantitative regulation conferred by flanking sequences. The largest of the lectin constructs contained approximately 3,00 base pairs (bp) of Le1 5′ flanking region and 1,500 bp of the 3′ flanking region. The smallest construct contained no 5′ flanking region and 194 bp of the 3′ flanking region. ELISA assays of lectin in individual tobacco seeds and Southern blot analyses confirmed that most constructs were inherited as unique insertion events. Maximal expression of Le1 required more than 338 bp of 5′ sequence, indicating that far upstream factors are involved in quantitative control of lectin expression. Lectin expression declined more than 80% between deletions with 1,700 versus 338 bp of 5′ flanking sequence. In contrast, developmental control of lectin expression was maintained by Le1 inserts with only 190 bp of 5′ sequence. The lectin promoter offers a potential means to target high levels of gene expression to the developing seeds of soybean or other dicotyledonous plants.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110206
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  • 45
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    Masthead (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110501
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  • 46
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    Chimeric genes and transgenic plants are used to study the regulation of genes involved in symbiotic plant-microbe interactions (nodulin genes) (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 182-196 
    Details
    ISSN: 0192-253X
    Keywords: nodulins ; leghemoglobin ; glutamine synthetase ; Enod2 ; cis-acting elements ; transacting factors ; Agrobacterium turnefaciens ; A. rhizogenes ; binary vectors ; plant transformation ; chimeric genes ; chloramphenicol acetyltransferase ; glucuronidase ; cytokinin induction ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Nodulin genes are plant genes specifically activated during the formation of nitrogen-fixing nodules on leguminous plants. These genes are interesting to study since they are not only induced in a specific developmental fashion by signals coming directly or indirectly from the rhizobial symbiont, but are also expressed in a tissue-specific manner. By examining the expression of chimeric nodulin-reporter genes in transgenic legume plants it has been shown that nodule specific expression is mediated by DNA sequences present in the 5′upstream region of several nodulin genes. Here we summarize the available data on these cis-acting elements and the trans-acting factors interacting with them. We also review experiments designed to identify rhizobial “signals” which may play a role in nodule specific gene expression.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110304
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    Cell cycle-regulated gene expression in transgenic plant cells (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 205-213 
    Details
    ISSN: 0192-253X
    Keywords: cauliflower mosaic virus 35S RNA ; cell cycle gene expression ; cis-acting element ; wheat histone H3 gene ; trnas-acting factor ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A majority of histone genes are expressed in the S phase during the cell cycle. Using the gene expression system of transformed sunflower cells into which wheat histone H3 gene was introduced by the Ti-plasmid gene transfer technique, we determined three cis-acting control sequences (hexameric, octameric, and nonameric motifs) which seemed to confer the S-phase-specific transcription of wheat histone genes. Furthermore, as candidates for regulatory transcription factors, three nuclear DNA-binding proteins HBP-la, HBP-lb, and HBP-2 that interact with the hexameric and nonameric motifs were identified. The structural analysis of the cDNA of HBP-la revealed that a nuclear protein has the leucine-zipper structure and a DNA-binding motif. The hexameric motif in the H3 gene was also seen in cauliflower mosaic virus 35S (CaMV 35S) promoter and shown to function as a regulatory element of this promoter. The wheat HBP-1b can interact with the hexameric motif of the CaMV 35S promoter. Much attention has been paid to the significance of the hexameric sequences within the H3 and CaMV 35S promoters and the DNA-binding proteins HBP-la and HBP-lb.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110306
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  • 48
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    Gene interactions and epigenetic variation in transgenic plants (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 214-223 
    Details
    ISSN: 0192-253X
    Keywords: Gene interactions ; cytosine methylation ; epigenetic variation ; transgenic plants ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Unusual gene interactions were observed in several doubly transformed tobacco plants which were obtained following sequential transformation steps using two T-DNAs encoding different selection and screening markers. The expression of T-DNA-I, which encoded kanamycin resistance (Kanr) and nopaline synthase (NOS), was suppressed in some, but not all, of the double transformants after the introduction of T-DNA-II, which encoded hygromycin resistance (Hygr) and octopine synthase (OCS). Double transformants in which T-DNA-I had been inactivated could produce KanrNOS+ progeny, but these were shown to lack T-DNA-II, thus establishing the role of this T-DNA in the suppression of T-DNA-I. Reversible cytosine methylation of the promoters of T-DNA-I genes was shown to correlate with their activation/inactivation cycle. In this paper we pursue further the questions of the mechanism of suppression of T-DNA-I genes by T-DNA-II, and also the timing and extent of demethylation of T-DNA-I promoters in Kanr progeny following the loss of T-DNA-II. We propose that the suppression is due to the competition between homologous regions on each T-DNA for binding to nuclear sites with fixed locations. We further suggest that incomplete demethylation patterns of T-DNA-I promoters in Kanr progeny reflect the existence in the shoot apex meristem of two cell populations, which have either methylated or unmethylated T-DNA-I promoters, respectively. Thus, Kanr progeny are epigenetic chimeras with respect to the expression of T-DNA-I genes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110307
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    Analysis of coat-color patterns in aggregation chimeras between BALB/cA and C3H/HeN mice with special reference to migratory patterns and clone number of epidermal melanoblasts (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 254-262 
    Details
    ISSN: 0192-253X
    Keywords: Video-image analysis ; contact inhibition ; collision theory ; neural crest ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Chimeras provide unique opportunities to study interactions between the phenotypically similar but genotypically allogeneic cell populations during embryogenesis in vivo. From the quantitative analysis of coat-color patterns in C3H/HeN↔BALB/cA chimeras, a model was proposed stating that the aggregability of the C3H/ HeN-derived melanoblasts in the chimeras was inversely related to the ratio between the mean free path of the epidermal melanoblasts in the normal C3H/He N mouse and that in the chimeras. As a corollary, the possibility was suggested that during the migration of melanoblasts, mechanisms identical with or similar to contact inhibition of movement might operate after collision between the isogeneic, but not between the allogeneic melanoblasts. With regard to the number of melanoblast clones in the trunk region of the mouse, the present series of analyses yielded the value of 24-28 arranged unilaterally; the value closely approximated the number of the somites in that region and provided further support for the proposition made earlier by Tachi [Dev Genet 9:121-154, 1988; “Development of Preimplantation Embryos and Their Environment.” New York: Alan R. Liss, Inc., 1989, pp 263-274].
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110403
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  • 50
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    Cell type specific expression of a CaMV 35S-GUS gene in transgenic soybean plants (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 289-293 
    Details
    ISSN: 0192-253X
    Keywords: Cell or tissue specificity ; Glycine max ; Transformation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A number of independently derived transgenic soybean plants expressing a chimeric β-glucuronidase (GUS) gene under the control of the 355 CaMV promoter and a nopaline synthase polyadenylation signal were recovered using direct DNA transfer via electric discharge particle acceleration. Expression of GUS in R, plants was localized using thin tissue sections. Many tissue types expressed GUS at various levels. Pericycle cells in root, parenchyma cells in xylem, and phloem tissues of stem and leaf had high levels of enzyme activity. Procambium, phloem, and cortex cells in root, vascular cambium cells in stem, and the majority of cortex cells in leaf midrib, expressed low or no GUS activity. Intermediate levels of GUS activity were detected in leaf mesophyll cells, certain ground tissue cells in stem and leaf midrib, and in trichome and epidermal guard cells. Thus, we conclude that the 35S CaMV promoter is cell-type specific and is developmentally regulated in soybean.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110407
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    Identification and purification of the cell surface glycoprotein homologous to PsA in different species of cellular slime mold on the basis of a shared carbohydrate epitope (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 484-491 
    Details
    ISSN: 0192-253X
    Keywords: Dictyostelium ; glycosylation ; cell adhesion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The monoclonal antibodies MUD1 and MUD50 recognize peptide and carbohydrate epitopes, respectively, on the Dictyoste-lium discoideum developmentally regulated cell surface glycoprotein PsA. PsA is a putative pre-spore cell adhesion molecule during the slug stage and is anchored to the cell membrane via a phos-phatidylinositol glycan. Here we report on the presence of a PsA-like homolog in several Dictyo-stelium species. The MUD1 epitope is mostly confined to the D. discoideum complex, and only one non-D. discoideum strain reacted strongly with this antibody. By contrast, the mAb MUD50 recognises a homologous molecule in several Dictyostelium species that do not react with MUD1. With mAb MUD50 immunoaffinity chromatography, it was possible to purify and obtain an amino-terminal sequence for the PsA homolog from the Dictvoste-lium sp. strain ZA3A and from one strain of D. pur-pureum.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110525
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    Nonsense suppression in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 410-417 
    Details
    ISSN: 0192-253X
    Keywords: Suppressor †RNA genes ; yeast ; lacZ expression in D. discoideum ; †RNATrp genes ; †RNAGlu genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We describe the generation of Dictyostelium discoideum cell lines that carry different suppressor †RNA genes. These genes were constructed by primer-directed mutagenesis changing a †RNATrp(CCA) gene from D. discoideum to a †RNATrp(amber) gene and changing a †RNAGlu(UUC) gene from D. discoideum to a †RNAGlu(ochre) as well as a †RNAGlu(amber) gene. These genes were stably integrated into the D. discoideum genome together with a reporter gene. An actin 6::lacZ gene fusion carrying corresponding translational stop signals served as a reported. Active β-galactosidase is expressed only in D. discoideum strains that contain, in addition to the reporter, a functional suppressor †RNA. Both amber suppressors are active in D. discoideum without interfering significantly with cell growth and development. We failed, however, to establish cell lines containing a functional †RNAGlu(ochre) suppressor. This may be due to the fact that nearly every message from D. discoideum known so far terminates with UAA. Therefore a †RNA capable of reading this termination codon may not be compatible with cell growth.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110514
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    Regulation of the anterior-like cell state by Ammonia in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 442-446 
    Details
    ISSN: 0192-253X
    Keywords: Prestalk cells ; prespore cells ; slugs ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ammonia appears to be an important regulatory signal for several aspects of the Dictyostelium life cycle. The postulated role of ammonia in the determination of the prespore pathway in cells of the slug stage has led us to examine the effect of ammonia on the prestalk/prespore ratio of migrating slugs. In the presence of 10-3 M ammonium chloride, the volume of the prestalk region decreases by 40.8%. The kinetics of the process make it unlikely that this is due to a shift in the differentiation pathway. A test of the hypothesis that the decrease in volume of the prestalk region is due to the conversion of prestalk cells to anterior-like cells shows that the percent of anterior-like cells in the posterior region increases by the amount predicted by the hypothesis. This suggests that ammonia may be the molecular signal, produced by the tip, that prevents anterior-like cells from chemotactically migrating to the tip and thereby becoming anterior cells. The effect of enzymatic removal of ammonia from vitally stained migrating slugs is the appearance of a series of dark stripes beginning at the posterior end and progressing forward. We interpret this as a result of progressive removal of anterior-like cells from tip dominance and essentially as the formation of new potential tips. Indeed, in a few cases one or even two of the stripes separate from the posterior of the cell mass and form small fruiting bodies. We consider the phenomenon of stripe formation further evidence that the tip acts on anterior-like cells through ammonia.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110519
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    Processing of neutral N-linked oligosaccharides during early Dictyostelium discoideum development (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 473-483 
    Details
    ISSN: 0192-253X
    Keywords: N-glycosylation ; glycoprotein sorting ; oligosaccharide processing ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have used metabolic radiolabeling with oligosaccharide precursors, coupled with subcellular fractionation, to examine the distribution of several classes of asparagine-linked oligosaccharides during early development. In Dictyostelium, we have observed endoglycosidase H (endo H)-sensitive structures with sizes corresponding to 10 (Hex10) and 11 (Hex11) hexose residues on the chitobiose core. Only Hex11 was detected as the major structure on fucosylated endo H-resistant species. All Hex11 species cofractionated with plasma membrane and secreted glycoproteins, whereas Hex10 appeared to be confined to intracellular membrane and soluble glycoproteins. Sulfated species correlated with lysosomal and secreted fractions, and glucose residues were markedly depressed in Hex11 of secreted glycoproteins. Outer branch structural studies have revealed several components of the endo H-sensitive species. Usingα-mannosidase and β-hexosaminidase as diagnostic tools, species elucidated thus far are: a structure with 10 mannoses, a structure with nine mannoses and an intersecting N-acetylglucosamine, structures with three glucoses and seven or eight mannoses and several larger species with multiple blocks to digestion.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110524
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    Announcement (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 512-512 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110527
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  • 56
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    Position-Dependent regulation of the prestalk-prespore pattern in Dictyostelium slugs (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 447-452 
    Details
    ISSN: 0192-253X
    Keywords: Pattern regulation ; cell sorting ; transplantation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In classical transplantation experiments, we have attempted to distinguish between cell sorting and position-dependent mechanisms of pattern formation during the regulation of amputated prespore regions of Dictyostelium slugs. Host and transplanted tissue were distinguished by prior labelling with 14C and 3H, and their distributions in the manipulated slugs were determined by double-label scintillation counting of serial sections of the slugs. First, we showed that the regenerated prestalk region is formed predominantly from the anterior of a prespore isolate. This disproves extreme cell sorting models, which hold that the new prestalk cells arise at random in the prespore mass, before sorting to the prestalk zone. Second, we showed that a proportion of posterior cells, which are not normally recruited into the new prestalk region, can be recruited into it if they are transplanted into the anterior of the prespore isolate. Recruitment of these cells occurs only during the first hour of regulation. We believe that these experiments prove a position-dependent mechanism of pattern formation during slug regulation. This in turn implies the existence of localized inductive signals in the regulating fragments. Although cell sorting occurs efficiently when cells are misplaced in the slug, it does not appear to play a major role in reforming the prestalk/prespore pattern.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110520
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    Biochemical and genetic analysis of the biosynthesis, sorting, and secretion of Dictyostelium lysosomal enzymes (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 454-462 
    Details
    ISSN: 0192-253X
    Keywords: Mutants ; proteolytic processing ; N-linked oligosaccharide ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Dictyostelium discoideum is a useful system to study the biosynthesis of lysosomal enzymes because of the relative ease with which it can be manipulated genetically and biochemically. Previous studies have revealed that lysosomal enzymes are synthesized in vegetatively growing amoebae as glycosylated precursor polypeptides that are phosphorylated and sulfated on their N-linked oligosaccharide side-chains upon arrival in the Golgi complex. The precursor polypeptiaes are membrane associated until they are proteolytically processed and deposited as soluble mature enzymes in lysosomes. In this paper we review biochemical experiments designed to determine the roles of post-translational modification, acidic pH compartments, and proteolytic processing in the transport and sorting of lysosomal enzymes. We also describe molecular genetic approaches that are being employed to study the biosynthesis of these enzymes. Mutants altered in the sorting and secretion of lysosomal enzymes are being analyzed biochemically, and we describe recent efforts to clone the genes coding for three lysosomal enzymes in order to better understand the molecular mechanisms involved in the targeting of these enzymes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110522
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    Biochemical and genetic analysis of an antigenic determinant found on N-linked oligosaccharides in Dictyostelium (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 463-472 
    Details
    ISSN: 0192-253X
    Keywords: Sulfated/phosphorylated oligosaccharides ; mutants ; lysosomal enzymes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Dictyostelium discoideum synthesizes many highly immunogenic carbohydrates of unknown structure and function. We have used monoclonal antibodies prepared against one of these called CA1 to investigate its structure and the consequences of its loss. CA1 is preferentially expressed on lysosomal enzymes as a specific arrangement of mannose-6-SO4 residues on N-linked oligosaccharides. Mutant strains HL241 and HL243 do not express CA1, and synthesize a truncated lipid-linked oligosaccharide (LLO) precursor that lacks the critical mannose residues needed for expression. The lesion appears to result from the loss of mannosyl transferase activity involved in LLO biosynthesis. The truncated LLO is poorly transferred to an artificial peptide acceptor in a cell-free N-glycosylation assay, and this appears to result from improper topological localization of the LLO or to a lower affinity of the LLO for the oligosaccharyl transferase. Although both mutants share these lesions, they are biochemically and genetically distinct. Only HL243 is lower in N-glycosylation in intact cells, and this is not a result of an altered structure of the LLO. There are other differences between the strains. HL241 can form fruiting bodies at a slower rate than normal while HL243 cannot aggregate. Genetic analysis of defects shows that the CA1 lesion in HL241 is recessive, while the lesions in both CA1 and in development are dominant and co-segregate in HL243 and are, therefore, likely to be in the same gene. Lysosomal enzyme targeting is normal but enzyme processing proceeds at a 2-3 fold slower rate in HL241 and HL243 compared to wild-type. Strain HL244 does not express CA1 since it completely lacks protein sulfation, but lysosomal enzyme targeting and processing proceeds at a normal rate, showing that sulfate is not essential for these processes. Alterations in oligosaccharide structure can have individualized effects on the biosynthesis of lysosomal enzymes. The results presented here illustrate how this approach can be used to study both the structure and function of carbohydrate epitopes.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110523
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  • 59
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    Formation of the Dictyostelium spore coat (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 492-506 
    Details
    ISSN: 0192-253X
    Keywords: Prespore vesicle ; cellulose ; polysac-charide ; acid hydrolase spore coat protein ; secretion ; flow cytometry ; confocal microscopy ; macrocyst ; cellular slime mold ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The spore coat forms as a rigid extracellular wall around each spore cell during culmination. Coats purified from germinated spores contain multiple protein species and an approximately equal mass of polysaccharide, consisting mostly of cellulose and a galactose/N-acetyl-galactosamine polysaccharide (GPS). All but the cellulose are prepackaged during prespore cell differentiation in a regulated secretory compartment, the prespore vesicle. The morphology of this compartment resembles an anastomosing, tubular network rather than a spherical vesicle. The molecules of the prespore vesicle are not uniformly mixed but are segregated into partially overlapping domains. Although lysosomal enzymes have been found in the prespore vesicle, this compartment does not function as a lysosome because it is not acidic, and a common antigen associated with acid hydrolases is found in another, acidic vesicle population. All the prespore vesicle profiles disappear at the time of appearance of their contents outside of the cell; this constitutes an early stage in spore coat formation, which can be detected both by microscopy and flow cytometry. As an electron-dense layer, the future outer layer of the coat, condenses, cellulose can be found and is located immediately beneath this outer layer Certain proteins and the GPS become associated with either the outer or inner layers surrounding this middle cellulose layer. Assembly of the inner and outer layers occurs in part from a pool of glycoproteins that is shared between spores, and unincorporated molecules loosely reside in the interspore matrix, a location from which they can be easily washed away. When the glycosylation of several major protein species is disrupted by mutation, the coat is assembled, but differences are found in its porosity and the extractibility of certain proteins. In addition, the retention or loss of proteolytic fragments in the mutants indicates regions of spore coat proteins that are required for association with the coat. Comparative examination of the macrocyst demonstrates that patterns of molecular distributions are not conserved between the macrocyst and spore coats. Thus spore coat assembly is characterized by highly specific intermolecular interactions, leading to saturable associations of individual glycoproteins with specific layers and the exclusion of excess copies to the interspore space.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110526
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    Temporal expression of genes encoding free radical-metabolizing enzymes is associated with higher mRNA levels during in utero development in mice (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 149-159 
    Details
    ISSN: 0192-253X
    Keywords: Superoxide dismutase ; glutathione peroxidase ; catalase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The interaction of reactive oxygen metabolites with DNA is well characterized and may result in mutagenesis, chromosome aberrations, and modulation of gene expression. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) catalyze enzymatic reactions to remove oxidant stresses, particularly O2- and H2O2. The role of these enzymes during in utero development of the embryo and the developmental pattern of expression of the embryonic genes encoding them is not known. We examined the in utero developmental expression and activity of the three free-radical-metabolizing enzymes in mice. We collected mouse fetuses at different stages of development and examined total RNA populations by Northern and slot blots using gene-specific cDNA probes. In addition to quantifying the probe-specific RNAs, activities of the three enzymes were also evaluated on the same tissue samples.The gene-specific RNAs and the associated enzyme activities are detectable with somite formation (day 8 postcoitus [p.c.]) in mice. The relative RNA values for each of the genes studied are higher in in utero stages as compared with the adult. The specific activities of these enzymes, on the other hand, follow a characteristic increase with development and growth. The relative RNA levels for each of the genes studied are higher during in utero growth and development than the relative enzyme activity values (between day 8 and day 18, third trimester) in the liver and carcass. This may suggest that the mRNA specific to these genes may accumulate in utero and are not translated immediately. Such accumulating transcripts are translated efficiently after birth, when these enzyme are particularly needed with the advent of aerobic respiration.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110205
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    Direct gene transfer to protoplasts: Fate of the transferred genes (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 176-181 
    Details
    ISSN: 0192-253X
    Keywords: Direct gene transfer ; transgenic plants ; expression of transgenes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Direct gene transfer to protoplasts is one of several methods developed for the production of transgenic plants. This method utilizes the efficient uptake of DNA from the surrounding medium by protoplasts (cell wall-less plant cells). Where a suitable protoplast system exists large numbers of transformant clones can be efficiently produced and often regenerated to normal fertile plants. This review concentrates on the fate of the DNA which is taken up into the protoplasts. Particular emphasis is given to the factors which can influence the integration and form of the transferred DNA, the expression of transferred genes, and the inheritance in further generations of those genes. The information available suggests (1) that DNA is taken up by a large proportion of the cells in a transformation mixture, (2) that this DNA forms complexes sometimes involving carrier DNA, (3) that fewer cells actually take up DNA into the nucleus, and (4) that the complex may be rearranged and/or amplified and then integrated into the genome. If the DNA is arranged in such a way that a gene can be expressed it does so in a normal manner and is stably inherited both mitotically and meiotically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110303
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    Chromatin structure of transferred genes in transgenic plants (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 233-247 
    Details
    ISSN: 0192-253X
    Keywords: Chromatin structure ; foreign gene expression ; transgenic plants ; Nicotiana tabacum ; position effect ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The chromatin structure of foreign genes in transgenic tobacco plants was investigated by digestion of nuclei with DNase I and micrococcal nuclease, respectively, followed by restriction and Southern analysis of the digestion products. The results were compared to the differential expression of the different transgenes. Two model systems were used: plants harbouring vector DNA derived from the disarmed vector pGV 3850 and plants harbouring the light-regulated and organ-specifically expressed potato ST-LS1 gene and the cotransferred ncpaline synthase (nos) reporter gene. Our results show that transferred genes are located in DNase l-sensitive domains in all transformants. Slight variations of DNase l-sensitivity of the transferred ST-LS1 constructs in different transformants neither reflected the between-transformant variability of expression nor the organ-specific activity of the transgenes. A deletion event was found responsible for silencing the ST-LS1 gene but not the nos gene in one of the transformants. Whereas no DNase l-hypersensitive sites were found within the 3850-T-DNA and the ST-LS1 gene, one prominent site was mapped to the nos promoter within the ST-LS1 construct in all transformants. Digestion of chromatin harbouring 3850-T-DNA with micrococcal nuclease resulted in a blurred nucleosomal pattern as compared to nucleolar and bulk chromatin, the extent of blurring being independent of the expression of transferred genes. The present results favour the “permissive domain” hypothesis which capitalizes on the chromatin surrounding the integration site as the determining factor for the chromatin structure of incoming alien genes. However, between-transformant variability of expression is not reflected by differential sensitivity to DNase I. Hence, other factors than chromatin structure must be involved in creating “position effects”.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110309
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    Quartet: A Drosophila developmental mutation affecting chromosome separation in mitosis (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 27-40 
    Details
    ISSN: 0192-253X
    Keywords: Maternal effect ; Drosophila embryogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Drosophila mutation, quartet, affects development at points in the life cycle that require intense mitotic activity. Examination of embryos affected by the maternal effect of quartet has revealed defects that can be attributed to incomplete chromosome separation at mitosis. These defects include uneven spacing of nuclei, strands of DNA creating bridges between nuclei, and abnormal amounts of DNA per nucleus. Nuclei in quartet-affected embryos also have a greater-than-normal number of centrosomes. Immunofluorescent examination of the spindles in quartet-affected embryos has revealed tripolar spindles and adjacent spindles that share a common spindle pole. Finally, chromosome separation distance was measured in anaphase and telophase spindles in quartet-affected embryos and found to be blocked in anaphase. Examination of mitotic figures in quartet larvae revealed a reduced mitotic index and an elevated frequency of abnormal mitotic figures. quartet could encode a function necessary for the disengagement of chromosomes in mitosis, for kinetochore function or for function of a spindle motor. Mutations in quartet prevent the post-translational modification of three abundant proteins. These proteins may be involved in chromosome separation in mitosis.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110105
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    Transcripts of individual Drosophila actin genes are differentially distributed during embryogenesis (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 15-26 
    Details
    ISSN: 0192-253X
    Keywords: Development ; gene regulation ; multigene family ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The temporal and spatial patterns of accumulation of transcripts from individual actin genes during Drosophila embryogenesis have been determined by in situ hybridization. We describe the subcloning into transcription vectors of unique DNA fragments derived from the 3′ transcribed, but nontranslated region of each actin gene. These fragments then served as templates for the synthesis in vitro of single-stranded, radioactive gene-specific RNA probes. Probe characterization and hybridization to developmental RNA blots are presented, demonstrated the independent developmental accumulation of actin transcripts from each gene. Each gene-specific probe has been hybridized in situ to the transcripts present in embryonic frozen sections. The results of these experiments have demonstrated that transcripts from each actin gene accumulate differentially in developing Drosophila tissues. The 5C and 42A actin genes are cytoplasmic actin genes, with transcripts distributed in all cells and tissues of the developing embryo. Therefore these genes presumably encode the cytoplasmic actins used for functions common to all cells. Transcripts from both cytoplasmic actin genes are evenly distributed in preblastoderm embryos, becoming localized to the periphery at blastoderm formation [5C: Burn et al.: Dev Biol 131:345-355, 1989]. Later in development, levels of these cytoplasmic transcripts vary in specific tissues. While the patterns of localization of 5C actin transcripts have been published [Burn et al.: Dev Biol 131:345-355, 1989], differential neurological localization is presented here; 42A transcripts are localized at higher concentrations in the midgut, the brain, nerve cord, and gonad. Both 87E and 57B transcripts accumulated in the developing larval body wall musculature, but at differing levels and in differing patterns. Transcripts of the 79B and the 88F actin genes were undetectable in embryos. The results of these experiments suggest dedicated contributions of individual actin genes to complex developmental processes.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110104
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    Mutations affecting embryonic cell migrations in Caenorhabditis elegans (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 49-64 
    Details
    ISSN: 0192-253X
    Keywords: Cell migration ; morphogenesis ; mutant analysis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Four recessive mutations that affect long-range embryonic migration of the two canal-associated neurons (CANs) in C. elegans were isolated and characterized with the goal of identifying genes involved in control of directed cell movement. Mutant animals were identified initially by their “withered” tails, a phenotype associated with abnormal CAN migration; the mutants were then analyzed for abnormal cell migrations by Nomarski microscopy. Based on genetic complementation tests, the mutations were assigned to four different loci, two new (mig-10 III, mig-11 III) and two previously identified (unc-39 V, vab-8 V). Mutations at all four loci affect CAN migration with high to moderate penetrance (the percentage of mutant animals that exhibit the phenotype). In addition, two other bilaterally symmetric pairs of neurons (ALM and HSN), the mesoblast M, and a pair of coelomocyte mother cells are affected by one or more of the mutations, generally with lower penetrance. With the exceptions of HSN and the right coelomocyte mother cell, which occasionally migrate beyond their normal destinations, the cells affected appear to migrate either incompletely or not at all. All the migration phenotypes show incomplete penetrance and variable expressivity, although genetic tests suggest that mutations at mig-10 and vab-8 result in complete or nearly complete loss of gene function. The variability in mutant phenotypes allowed tests for interdependence of several of the affected migrations; all those analyzed appeared independent of one another. The possible nature of the mutant defects and possible roles of these four loci in cell migration are discussed.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110107
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    Molecular analysis of a phylogenetically conserved carrot gene: Developmental and environmental regulation (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 65-76 
    Details
    ISSN: 0192-253X
    Keywords: Somatic embryogenesis ; gene regulation ; transgenic plants ; β-glucuronidase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Extensive studies of gene expression programs in carrot somatic embryos identified a gene, designated Dc3, that serves as a reliable molecular marker for the acquisition of embryogenic potential by carrot cells in culture. The complete sequence of a carrot genomic region, DcG3, encoding a Dc3-like mRNA, was determined. The DcG3 transcription unit contains a single intron and encodes mRNA that is expressed at high levels in embryonic tissue but is undetectable in somatic tissue of carrot. The predicted protein sequence of DcG3 is 163 amino acids and includes two approximately 50 amino acid direct repeats which in turn include additional repetitive elements with an unusual distribution of charged amino acids. Dc3 and Dc3-like mRNAs are encoded by a small divergent gene family. Furthermore, similarities of the Dc3 gene family with genes from other plant species that are expressed in response to environmental and developmental cues suggest a possible role in seed desiccation and possibly in more general water-stiess responses in plants. Analysis of transgenic tobacco containing a β-glucuronidase (GUS) reporter gene fused to a 1.7 kb 5′ upstream element of DcG3 defined a promoter/enhancer complex that confers developmentally and environmentally regulated expression of GUS activity. Thus, DcG3 is phylogenetically conserved together with the trans-acting factors required for its regulated expression in transgenic tobacco.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110108
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    Announcement (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 123-123 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110113
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    Masthead (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990) 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110201
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    Stages of cell hair construction in Drosophila (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 133-140 
    Details
    ISSN: 0192-253X
    Keywords: Morphogenesis ; heat shock ; phenocopies ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The construction of cell hairs (trichomes) on the wings of Drosophila occurs in synchrony on 30,000 cells over a period of about 20 hr. Changes in both morphology and patterns of protein synthesis occur rapidly during this time period. In this report we describe the use of stressinduced (heat shock) abnormalities in morphogenesis to provide further details on the stepwise processes of differentiation within single wing cells. A cartoon summary of the overall process and a discussion of some possible mechanisms is included.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110203
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    Ponticulin, a developmentally-regulated plasma membrane glycoprotein, mediates actin binding and nucleation (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 354-361 
    Details
    ISSN: 0192-253X
    Keywords: Amoeboid movement ; cell adhesion ; cytoskeleton ; cell motility ; Dictyostelium ; microfilaments ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ponticulin is a 17,000-dalton transmembrane glycoprotein that is involved in the binding and nucleation of actin filaments by Dictyostelium discoideum plasma membranes. The major actin-binding protein isolated from these membranes by F-actin affinity chromatography, ponticulin also binds F-actin on blot overlays. The actin-binding activity of ponticulin in vitro is identical to that observed for purified plasma membranes: it resists extraction with 0.1 N NaOH, is sensitive to high salt concentrations, and is destroyed by heat, proteolysis, and thiol reduction and alkylation. A cytoplasmic domain of ponticulin mediates binding to actin because univalent antibody fragments directed against the cytoplasmic surface of this protein inhibit 96% of the actin-membrane binding in sedimenlation assays. Antibody specific for ponticulin emoves both ponticu-lin and the ability to reconstitute actin nucleation activity from detergent extracts of solubilized plasma membranes. Levels of plasma membrane ponticulin increase 2- to 3-fold during aggregation streaming, when cells adhere to each other and are highly motile. Although present throughout the plasma membrane, ponticulin is preferentially localized to some actin-rich membrane structures, including sites of cell-cell adhesion and arched regions of the plasma membrane reminiscent of the early stages of pseudopod formation. Ponticulin also is present but not obviously enriched at phagocytic cups of log-phase amebae. These results indicate that ponticulin may function in vivo to attach and nucleate actin filaments at the cytoplas-mic surface of the plasma membrane. A 17,000-dalton analogue of ponticulin has been identified in human polymorphonuclear leukocyte plasma membranes by immunoblotting and immunofluo-rescence microscopy. These findings suggest that the structure and function of ponticulin in motile cells has been evolutionarily conserved.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110506
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    Recent advances in the molecular genetics of Dictyostelium (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 388-390 
    Details
    ISSN: 0192-253X
    Keywords: Transformation ; electroporotion ; gene targetting ; antisense RNA ; complementation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: DNA mediated transformation is a critical technique for uniting genetic, molecular genetic and reverse genetic approaches to a wide range of problems in cell and molecular biology. In Dictyostelium, there is now the capability not only to manipulate DNA sequences in vitro and put them back into the cell, but also to alter the sequences of endogenous chromosomal genes through high frequency homologous recombination. This means that the range of gene manipulation techniques that have made yeast such a useful system should now be applicable in Dictyostelium. For studying problems such as cellular motility, morphogenesis, and gene regulation, few organisms have the combination of features offered by Dictyostelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110510
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    Positive selection for Dictyostelium mutants lacking uridine monophosphate synthase activity based on resistance to 5-fluoro-orotic acid (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 396-402 
    Details
    ISSN: 0192-253X
    Keywords: Transformation ; Dictyostelium discoideum ; UMP-synthase/ura-complementation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Whereas transformation ofDictyostelium discoideum now can be done routinely and reliably, there is increasing demand for a system that allows selection of cells that have gone through repeated transformation cycles. Such a system is presented here. Selection is based on resistance to 5-fluoro-orotic-acid (5-FOA). D. discoi-deum is highly sensitive to this drug, and cells can survive only in the presence of 5-FOA if they carry a defective UMP-synthase gene. After transformation with a plasmid carrying a cloned version of the UMP-synthase gene, 5-FOA resistant cells are obtained at high frequency. Because 5-FOA-resistant cells depend on exogenously added uracil, these cells can be taken through a second round of transformation. A plasmid-borne UMP-synthase gene renders 5-FOA-resistant cells phenotypically ura +. Finally, cells can be further transformed using the standard G418 selection system.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110512
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    Separate molecular mechanisms regulate CAT2 gene expression before and after glyoxysome maturation in two genetic lines of maize (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 280-288 
    Details
    ISSN: 0192-253X
    Keywords: Seed germination ; transcription control ; compartmentalization ; polysomes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The temporal expression pattern of the CAT-2 catalase isozyme in scutella of Zea mays seedlings normally coincides with that of other major glyoxysomal enzymes. In standard genetic lines (e.g., W64A), the CAT-2 enzyme is synthesized de novo after imbibition, reaches a peak at approximately 4 days later, and then declines steadily. In a high CAT-2 genetic line, R6-67, the enzyme accumulates in a linear fashion for at least 8 days after imbibition and reaches a level 3-fold higher than in W64A. During the first 9 days of early seedling growth in W64A, the correlation between Cat2 mRNA levels and CAT-2 protein suggests that pretranslational control governs Cat2 gene expression. In R6-67, the steady rise in CAT-2 protein appears to result from a pretranslational control mechanism in which Cat-2 mRNA apparently never declines to levels which would limit the rate of accumulation of CAT-2 protein. In addition, the amount of Cat2 mRNA bound to polysomes is 3-fold higher in R6-67 at day 9 relative to W64A at day 9, reflecting a much greater capacity to synthesize CAT-2 later in development. Despite substantial differences in Cat2 mRNA levels between genetic lines, early CAT-2 protein accumulation is similar until day 5, when other glyoxysomal enzymes also attain maximal activity levels. The early increase in CAT-2, between day 2 and day 5 post-imbibition, occurs despite a sharp decline in polysomal Cat2 mRNA. This is related to a transient decline in total extractable polysomes which paradoxically coincides with the peak in glyoxysomal enzyme activities. Early Cat2 gene expression is likely controlled by the compartmentalization of CAT-2 in glyoxysomes.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110406
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    Molecular and developmental analyses of the protein encoded by the Drosophila gene Ectodermal (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 310-317 
    Details
    ISSN: 0192-253X
    Keywords: Drosophila acidic protein ; leader sequence ; tubular structures ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Drosophila gene ectodermal (ect, located at 67D8-10 on chromosome 3) is expressed for a short period at mid-embryogenesis in all ectodermally derived tissues except the nervous system. During this stage the tissues involved form tubular structures by a process of invagination followed by cell fusion. Here we report the sequence of the ect protein as deduced from the longest ORF (280 codons) of an ect cDNA. The principal molecular features of the ect protein are: (1) a consensus leader sequence for targeting to the rough ER; (2) a central domain containing a remarkably high density of acidic residues arranged in large clusters separated by smaller clusters of hydrophobic residues; (3) a consensus nuclear-targeting sequence near the C-terminus; (4) a single tyrosine residue located at a potential tyrosine-sulfation site. The antibody staining pattern of the ect protein corresponds to the in situ hybridization pattern of the transcript. A possible role for the ect protein in the complex process of fubular formation that occurs in embryonic ectodermal tissues is discussed.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110410
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    Introduction (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 327-327 
    Details
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110502
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    Mechanisms of amoeboid chemotaxis: An evaluation of the cortical expansion model (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 333-340 
    Details
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; actin ; ABP-120 ; elongation factor 1 alphc ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In this work we evaluate the cartical expansion model for amoeboid chemo-taxis with regard to new information about molecular events in the cytoskeleton following chemo-tactic stimulation of Dictyostelium amoebae. A rapid upshift in the concentration of chemoattrac-tant can be used to synchronize the motile behavior of a large population of cells. This synchrony presents an opportunity to study the biochemical basis of morphological changes such as pseudopod extension that are required for amoeboid chemotaxis. Changes in the composition and activity of the cytoskeleton following stimulation can be measured with precision and correlated with important morphological changes. Such studies demonstrate that activation of actin nucleation is one of the first and most crucial events in the actin cytoskeleton following stimulation. This activation is followed by incorporation of specific actin cross-linking proteins into the cytoskeleton, which are implicated in the extension of pseudopods and filopods. These results, as well as those from studies with mutants deficient in myosin, indicate that cortical expansion, driven by focal actin polymerization, cross-linking and gel osmotic swelling, is an important force for pseudopod extension.It is concluded that whereas three forces, frontal sliding, tail contraction, and cortical expansion may cooperate to produce amoeboid movement, the cortical expansion model offers the simplest explanation of how focal stimulation with a chemoat-tractant causes polarized pseudopod extension.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110504
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    Localization, expression, evolutionary conservation, and structure of the 30,000 dalton actin bundling protein of Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 362-368 
    Details
    ISSN: 0192-253X
    Keywords: Dictyostelium ; filopodia ; actin binding proteins ; calcium ; cell motility ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Dictyostelium discoideum 30,000 dalton actin-binding protein is an actin cross-linking protein that organizes formation of parallel bundles of actin filaments in vitro, and is present in filopodia in living cells. This protein binds calcium directly and exhibits a decreased affinity for actin filaments in the presence of micromolar calcium. In this work, the existence of antigenic homologs of the 30,000 dalton protein in Physarum polycephalum, Schistosoma mansoni, Chara carolina, and Drosophila melanogaster is detected by use of affinity purified antibody and electrophoretic blotting methods. The expression of this protein during development of Dictyostelium is also analyzed, revealing a progressive 3-fold decrease in the level of this protein in amoebae between the vegetative and slug stages. A highly ordered structure of bundles of actin and the 30,000 dalton protein formed in vitro is inferred from the presence of transverse striations on the bundles with a minor periodicity at 11.4 nm and a major periodicity at 33.9 nm. Finally, we propose a working model of the interaction of this actin cross-linking protein with actin filaments to form bundles.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110507
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    Cell-cell adhesion and morphogenesis in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 377-387 
    Details
    ISSN: 0192-253X
    Keywords: Cell-cell ; adhesion molecule ; cell binding site ; cell aggregation ; development ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During development of Dictyostelium discoideum, cells acquire EDTA-resistant cell-cell adhesion at the aggregation stage. The EDTA-resistant cell binding activity is associated with a cell surface glycoprotein of Mr 80,000 (gp80), which mediates cell-cell binding via ho-mophilic interaction. Analysis of the structure of gp80 deduced from cDNA sequence reveals the presence of three internally homologous segments in the NH2-terminal domain, which also contains regions with homology to the neural cell adhesion molecule. Secondary structure predictions show an abundance of β-structures and very few α-helices. This is confirmed by circular dichroism measurements. It is likely that the homologous segments are organized into globular structures, extended from the cell surface by a Pro-rich stalk domain. The cell binding activity of gp80 resides within the first globular repeat of the NH2-terminal domain and has been mapped to a 51 amino acid region between Val123 and Leu 173. Synthetic oligopeptides corresponding to sequences within this region have been prepared and assayed for their ability to bind to cell surface gp80. Results lead to identification of the homophilic binding site to an octapeptide sequence within this region. Synthetic peptides containing this octapeptide sequence and univalent antibodies directed against this site block the formation of organized cell streams during aggregation. Although cell aggregates are eventually formed, most fail to undergo further development to give rise to slugs and fruiting bodies, indicating that cell-cell adhesion involving gp80 is an important step in normal morphogenesis.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110509
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    Quantification of transformation efficiency using a new method for clonal growth and selection of axenic Dictyostelium cells (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 403-409 
    Details
    ISSN: 0192-253X
    Keywords: Electroporation ; soft-agarose ; G418 ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A new method for clonal growth of Dictyostlium axenic amoebae has been developed. Cells are plated in growth medium containing 1% ultra-low gelling temperature agarose. Cells grow normally in the agarose and form colonies up to several millimeters in diameter. When the colonies have grown to a sufficient size, they begin multicellular development. Pseudoplasmodia are formed, migrate to the surface of the agar, and then undergo fruiting body formation. Cells can be removed from the soft agarose colonies with a toothpick or by picking spores from the fruiting bodies. This method should be useful for drug, auxotrophic, and temperature selections where clonal maintenance of axenic colonies is important.This method has been used in combination with a selection for resistance to G418 to isolate independent colonies following DNA-mediated transformation. Several parameters in the calcium phosphate and electroporation transformation protocols have been optimized and the transformation frequency qualified. Independent transformed colonies are obtained at a frequency of 1 in 104 to 1 in 105 cells when integrating plasmids are introduced using calcium phosphate coprecipitation. The frequency is about tenfold higher when extrachromosomal shuttle vectors are introduced into cells.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110513
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  • 80
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    Timing of the formation of the prestalk and prespore zones in Dictyostelium discoideum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 439-441 
    Details
    ISSN: 0192-253X
    Keywords: Cellular slime molds ; timing of differentiation ; differentiation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Vital dyes have been extensively used in many laboratories to distinguish the prestalk and prespore zones of a migrating slug in Dictyostelium discoideum. Here we present evidence that the two zones do not form immediately following aggregation, as is sometimes assumed, but only after 1-4.5 hr of migration. When the transition to the two-toned state occurs, it changes very quickly, in a matter of approximately 10 min. Furthermore, it can be rapidly induced by submerging the slug in mineral oil. The time of appearance of the zones is correlated with previously reported changes in the distribution of cyclic AMP secretion and with changes in regulation properties along the axis of the slug.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020110518
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  • 81
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    Analysis of developmentally expressed antigens in Polysphondylium pallidum (1990)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 11 (1990), S. 427-438 
    Details
    ISSN: 0192-253X
    Keywords: Cellular slime molds ; patterning ; development ; immunoblotting ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A series of monoclonal antibodies were previously raised against developing Polysphondylium pallidum cells. In this work, six of these antibodies have been used as probes to identify and characterize antigens regulated during development. Soluble and membrane fractions of P. pallidum cells at six stages of development or three stages of cyclic adenosine monophosphate (cAMP)-induced development were run in sodium dodecyl sulfate (SDS)-polyacrylamide gels and subjected to Western blot analysis. Three of the monoclonals, anti-Tp200, anti-Tp423, and antiPg 101, stain sorogen tips. Tp423 and Tp200 are membrane-associated antigens; both are stable to urea extraction, and Tp200 remains in the membrane after NaOH extraction. Tp423 is present in starved cells but is more prominent in sorogens and particularly in cAMP-developed cells. In contrast, Tp200 is first detected in early to mid-aggregation and is more abundant late in development. Pg101, which is expressed as a gradient with its highest concentration in tips, first appears in tight aggregates but is much more abundant in sorogens; unlike the Tp antigens, Pg101 is not greatly induced in cAMP-developed cells. All three of these antigens undergo changes in apparent molecular weight at the tight aggregate or sorogen stage: The gel mobilities of Tp200 and Pg101 increase, whereas that of Tp423 decreases. In addition to the tip-specific monoclonals, two monoclonals that stain all but the tips of sorogens have been used for analysis. One of these, anti-3D 10Pnk stains most cells within secondary tips, whereas anti-3D 10Dif does not. 3D 10Dif is membrane associated; it is present very early in development, increasing two- to threefold through the sorogen stage and diminishing in late cAMP-developed cells. 3D 10Pnk is a mostly soluble species first detected in late streaming. Anti-1c3, a sixth monoclonal, which stains nuclei uniformly throughout sorogens, is also developmentally expressed. 1c3 is mainly membrane associated and is expressed from late streaming through the sorogen stage.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/dvg.1020110517
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    Chromosome constitution of highly motile mouse sperm (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 27 (1990), S. 168-172 
    Details
    ISSN: 1040-452X
    Keywords: Motility ; Genetics ; Sex chromosome ratio ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In this study, we address the relationship between motility and genetic content of mouse sperm. The chromosome complements of highly motile mouse sperm, selected using the swim-up technique, were analyzed after in vitro fertilization, at the first cleavage state. They were compared to those of unselected sperm. Identification of male and female chromosome sets was possible because of their differential condensation at the first mitotic division. In vitro fertilization, swim-up separation, chromosome preparation, and staining were carried out using standard techniques. The results indicate that highly motile mouse sperm did not differ in types and frequencies of chromosomal abnormalities from those not selected for motility. Moreover, separation of motile sperm does not deviate the sex ratio from the theoretical 1:1.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080270213
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  • 83
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    Yeast flocculation: Cationic inhibition (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 77-86 
    Details
    ISSN: 0749-503X
    Keywords: Flocculation ; yeast ; salt inhibition ; pH value ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Yeast flocculation was inhibited by high concentrations of a number of salts. Calcium and magnesiun salts were potent inhibitors and cesium salts were least effective. Partial inhibitors by different salts additive and were completely reversible by salt removal. Inhibition by salts was time dependent; prolonged incubation increased the degree of inhibition. Salt inhibition was partly caused by the action of salts lowering the buffer pH value, and partly caused by chaotropic inhibition of proteins on the surfaces of flocculent cells. Flocculation receptors on non-flocculent cells were ubaffected by high salt concentration. At sub-inhibitory salt concentrations, there was an enhancement of flocculation in both rate and extent.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060109
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    Twenty years after, but younger than before. The Yeasts, 2nd Edition, Volume 3, Metabolism and Physiology of Yeasts. Edited by A. A. Rose and J. S. Harrison. Published by Academic Press, London and San Diego, at £55 (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 171-171 
    Details
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060211
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    Yeast Saccharomyces cerevisiae selectable markers in pUC18 polylinkers (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 363-366 
    Details
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; Selectable markers ; Plasmids ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A set of plasmids was constructed that contain the yeast selectable markers HIS3, LEU2, TRP1 or URA3 embedded in the multiple cloning site of pUC18.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/yea.320060502
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  • 86
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    The glucanase-soluble mannoproteins limit cell wall porosity in Saccharomyces cerevisiae (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 491-499 
    Details
    ISSN: 0749-503X
    Keywords: Cell wall porosity ; permeability ; mannan ; cell wall composition ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cell porosity of batch-grown Saccharomyces cerevisiae was maximal in the early exponential phase and fell off rapidly to lower levels in later growth phases.Treatment of stationary-phase cells with alpha-mannosidase restored wall porosity to the level of cells in early exponential phase. When cells in the early exponential phase were treated with alpha-mannosidase, or tunicamycin, an inhibitor of N-glycosylation, even higher porosities were obtained. Mutants with truncated mannan side-chains in their wall proteins also had very porous walls. The importance of the mannan side-chains for wall porosity was also seen during sexual induction. Treatment with alpha pheromone, which leads to the formation of wall proteins with shorter mannan side-chains, enhanced wall porosity.Disulphide bridges also affect cell wall porosity. They were predominantly found in the glucanase-soluble wall proteins. Because the main part of the mannan side-chains is also found in this family of wall proteins, our results demonstrate that the glucanase-soluble mannoproteins limit cell wall porosity in yeast.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/yea.320060606
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    Osmoregulatory active sodium-glycerol co-transport in the halotolerant yeast Debaryomyces hansenii (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 187-191 
    Details
    ISSN: 0749-503X
    Keywords: Halotolerance ; osmoregulation ; glycerol-sodium symport ; glycerol-potassium symport ; sodium-proton exchange ; Debaryomyces hansenii ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Several authors have shown that the halotolerant yeast Debaryomyces hansenii, when growing exponentially in glucose medium in the presence of sodium chloride, maintains osmotic balance by establishing sodium and glycerol gradients of opposite signs across the plasma membrane. Evidence is presented here that the two gradients are linked through a sodium-glycerol symport that uses the sodium gradient as a driving force for maintaining the glycerol gradient. The symporter also accepts potassium ions as co-substrate. The kinetic parameters at 25°C, pH 5·0 were the following: Vmax, decreasing from over 500 to less than 40 μmol g-1 per h over a concentration range of 0-3 M extracellular sodium chloride; Km (glycerol) 0·40-0·6 mM over the same range; Km (sodium ions) 16·0 ± 3·21μM; Km, (potassium ions) 10·4 ± 3·6μM. Furthermore, it was observed that glycerol uptake was accompanied by proton uptake when extracellular sodium chloride was present and that the protonophore carbonylcyanide-M-chlorophenylhydrazone induced collapse of the glycerol gradient, supporting earlier proposals by others that the sodium gradient is maintained by an active sodium-proton exchange mechanism.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060303
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    The alcohol dehydrogenase system in the yeast, Kluyveromyces lactis (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 193-204 
    Details
    ISSN: 0749-503X
    Keywords: Kluyveromyces lactis ; alcohol dehydrogenase ; gene regulation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have studied the alcohol dehydrogenase (ADH) system in the yeast Kluyvefromyces lactis. Southern hybridization to the Saccharomyces cerevisiae ADH2 gene indicates four probable structural ADH genes in K. lactis. Two of these genes have been isolated from a genomic bank by hybridization to ADH2. The nucleotide sequence of one of these genes shows 80% and 50% sequence identity to the ADH genes of S. cerevisiae and Schizosaccharomyces pombe respectively. One K. lactis ADH gene is preferentially expressed in glucose-grown cells and, in analogy to S. cerevisiae, was named K1ADH1. The other gene, homologous to K1ADH1 in sequence, shows an amino-terminal extension which displays all of the characteristics of a mitochondrial targeting presequence. We named this gene K1ADH3. The two genes have been localized on different chromosomes by Southern hybridization to an orthogonal-field-alternation gel electrophoresis-resolved K. lactis genome. ADH activities resolved by gel electrophoresis revealed several ADH isozymes which are differently expressed in K. lactis cells depending on the carbon source.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/yea.320060304
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  • 89
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    Dekkera, Brettanomyces and Eeniella: Electrophoretic comparison of enzymes and DNA-DNA homology (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 299-310 
    Details
    ISSN: 0749-503X
    Keywords: Dekkera ; Brettanomyces ; Eeniella ; DNA ; enzymes ; systematics ; yeasts ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The taxonomic status of various species of Dekkera, Brettanomyces and Eeniella was examined by electrophoretic comparison of enzymes, by deoxyribonucleic acid homology and by physiological characterization. These studies demonstrated that two teleomorphic Dekkera species, D. anomala and D. bruxellensis (Synonym. D. intermedia), and four anamorphic Brettanomyces species, B. anomalus (synonym B. claussenii), B. bruxellensis (synonym B. abstinens, B. custersii, B. Intermedius, B. lambicus), B. custersianus and B. naardenesis, can be recognized. The anamorphic genus Eeniella remained as a separate, monotypic taxon.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060403
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  • 90
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    Analysis of the THR4 region on chromosome III of the yeast Saccharomyces cerevisiae (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 353-361 
    Details
    ISSN: 0749-503X
    Keywords: Threonine metabolism ; amino acid biosynthesis ; homologous domains ; chromosome III ; gene organisation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The gene encoding theonine synthase (THR4) from the yeast Saccharomyces cerevisiae was cloned by complementation of a thr4 mutant. This gene was also found on a lambda clone (5239) consisting of a fragment of chromosome III inserted in the vector lambda MG3. The THR4 gene encodes a protein of 514 amino acids (M.W. 58 kDa), which has extensive homologies with E. coli threonine synthase (thrC) and B. subtilis threonine synthase. The 5′ flanking region of the gene contains three regulatory sequences. [TGACT(C)] for the general amino acid control (GCN).About 130 bp downstream of the THR4 gene another open reading frame (563 amino acids) is found in the opposite orientation. This may imply that this open reading frame, called CTR86, shares a terminator region with THR4. The function of the protein encoded by CTR86 is not yet clear, but the fact that the upstream region contains a GCN4 responsive site that the gene product may also be involved in amino acid biosynthesis.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060408
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  • 91
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    The chromosomal constitution of wine strains of Saccharomyces cerevisiae (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 367-382 
    Details
    ISSN: 0749-503X
    Keywords: Yeast genetics ; wine yeast ; Saccharomyces cerevisiae ; chromosomes ; karyotyping ; aneuploidy ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A general procedure is described for determining the chromosomal constitution of industrial strains of Saccharomyces cerevisiae based on analysis of segregation frequencies for input markers among random spore progeny of industrial-laboratory strain hybrids. The multiple auxotrophic haploid testers used carried a dominant erythromycin-resistance marker, allowing hybrids to be selected in mass matings with produced by the wild-type industrial strains. Analysis a number of independent crosses between the haploid testers and an unselected population of spores of each wine strain distinguished between disomic, trisomic and tetrasomic chromosomal complements in the parents. Possible explanations for a significant class of aberrant segregation frequencies are discussed.Results of the analysis indicate that UCD Enology 522 (Montrachet) is diployed and possibly trisomic for chromosome VII; 522X is diploid; UCD Enology 505 (California Champagne) is disomic for chromosome XVI, trisomic for chromosomes I, II, III, VI, VIII, IX, X, XII, XV, tetrasomic for chromosomes IV, XI, XIII, XIV and either trisomic or tetrasomic for chromosomes V and VII; and that UCD Enology 595 (Pasteur Champagne) is disomic for chromosomes I, II, III, IX, XVI, trisomic for chromosomes IV, VI, X, XII, XIV, XV, tetrasomic for chromosomes V, VIII, XI, XIII, and either disomic or tetrasomic for chromosome VII.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060503
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    Mapping of the trifunctional fatty acid synthetase gene FAS2 on chromosome XVI of Saccharomyces cerevisiae (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 411-415 
    Details
    ISSN: 0749-503X
    Keywords: Multifunctional FAS2 gene ; Chromosome hybridisation ; spo11 mapping ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The trifunctional FAS2 gene encoding subunits α of the Saccharomyces cerevisiae fatty acid synthetase complex was mapped on the left arm of chromosome XVI 24 centinorgans proximal to GAL4 and 39 centimorgans distal and PEP4 relative to the centromere. Mapping was achieved by three-independent methods: meiotic co-segragation of FAS2 and ARO7 in recombination-deficient spo11-mutants; tetrad analysis of crosses between FAS2, GAL4 and PEP4; and Southern hybridization of purified FAS2 DBA with individual yeast chromosomes separated by pulsed-field gel electrophoresis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060506
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    Ornithine decarboxylase in Saccharomyces cerevisiae: Chromosomal assignment and genetic mapping of the SPE1 gene (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 455-460 
    Details
    ISSN: 0749-503X
    Keywords: Ornithine decarboxylase ; putrescine ; SPE1 gene ; spe10 mutation ; chromosome XI ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The gene for ornithine decarboxylase in Saccharomyces cerevisiae, SPE1, has been assigned to chromosome XI by the technique of transverse alternating pulsed field electrophoresis and DNA-DNA hybridization. Genetic mapping by tetrad analysis shows that the SPE1 gene is located on the left arm of chromosome XI, 6 cM from the LAP1 gene and 43 cM from the TRP3 gene. The spe10 mutation previously isolated in this laboratory is mapped to the N-terminal region of the SPE1 gene, and therefore should be designated as a spe1 allele.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060602
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    An assay of relative cell wall porosity in Saccharomyces cerevisiae, Kluyveromyces lactis and Schizosaccharomyces pombe (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 483-490 
    Details
    ISSN: 0749-503X
    Keywords: Cell wall porosity ; permeability ; polycation assay ; cell wall structure ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have developed a new assay to determine relative cell wall porosity in yeasts, which is based on polycation-induced leakage of UV-absorbing compounds. Polycations with a small hydrodynamic radius as measured by gel filtration (poly-L-lysine) caused cell leakage independent of cell wall porosity whereas polycations with a large hydrodynamic radius (DEAE-dextrans) caused only limited cell leakage due to limited passage through the cell wall. This allowed the ratio between DEAE-dextran- and poly-L-lysine-induced cell leakage to be used as a measure of cell wall porosity in Saccharomyces cerevisiae, Kluyveromyces lactis and Schizosaccharomyces pombe. Using this assay, we found that the composition of the growth medium affected cell wall porosity in S. cerevisiae. In addition, we could show that cell wall porosity is limited by the number of disulphide bridges in the wall and is dependent on cell turgor. It is argued that earlier methods to estimate cell wall porosity in S. cerevisiae resulted in large underestimations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060605
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  • 95
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    Assembly of amine oxidase and D-amino acid oxidase in the cytosol of peroxisome-deficient mutants of the yeast Hansenula polymorpha during growth of cells on glucose in the presence of primary amines or D-alanine as the sole nitrogen source (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 501-509 
    Details
    ISSN: 0749-503X
    Keywords: Hansenula polymorpha ; peroxisomes ; peroxisome-deficient mutants ; amine oxidase ; D-amino acid oxidase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have studied growth of two peroxisome-deficient mutant strains of Hansenula polymorpha on glucose in the presence of different organic nitrogen sources (methylamine, ethylamine and D-alanine), the metabolism of which is mediated by peroxisome-borne oxidases in wild-type (WT) cells. Both strains grew well on each of these substrates with growth rates comparable to WT cells. Growth on both methylamine and ethylamine was associated with enhanced levels of catalase and amine oxidase in the cells; in D-alanine-grown cells D-amino acid oxidase activity and increased. In WT cells of H-polymorpha the activities of these enzymes were confined to the peroxisomal matrix; however, in both peroxisome-deficient strains their activities were localized in the cytosol. Electron microscopy indicated that, dependent on the stage of growth, the enzymes may form large protein aggregates.The molecular masses of both amine oxidase and D-amino acid oxidase in the mutant strains were identical to their respective counterparts in WT cells, indicating that both proteins were correctly assembled and active in the cytosol.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060607
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  • 96
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    Excessive membrane development following exposure of the methylotrophic yeast Hansenula polymorpha to oleic acid-containing media (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 511-519 
    Details
    ISSN: 0749-503X
    Keywords: Peroxisomes ; oleic acid ; β-oxidation ; membrane proliferation ; Hansenula polymorpha ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We studied the physiological responses of Hansenula polymorpha during adaptation of cells to oleic acid-containing media. Growth experiments indicated that the organism was unable to use oleic acid as the sole source of carbon and energy. However, upon incubation of glucose-grown cells in mineral media containing oleic acid, activities of various enzymes of the β-oxidation pathway were induced. These enzymes were localized in microbodies together with alcohol oxidase. Furthermore, a drastic increase in phospholipid content of the cells was observed; this was due to a rapid proliferation of membranes. These consisted of a variable number of membranous layers which were continuous with the peroxisomal membrane. Upon continued incubation, the membrane proliferations extended and large compartments were formed. This process was dependent on the presence of peroxisomes in the cells since it was not observed in peroxisome-deficient mutant strains of H. polymorpha. The newly formed membranous compartments differed from peroxisomes since they did not contain peroxisomal matrix proteins; these were confined to the single enlarged organelle which was incorporated in the membranous structure and characterized by a large alcohol oxidase crystalloid. The membranous compartments are considered to be whole entities since they could not be separated from the peroxisomes by common cell fraction methods; also they were degraded entirely after a shift of cells to glucose-excess condition.Freeze fracturing reveled that the substructure of the membranes greatly resembled that of normal peroxisomal membranes. Since a distinct enhancement of different peroxisomal membrane proteins was observed during the initial hours after the shift, we assume that exposure of H. polymorpha to acid lead to a drastic overproduction of peroxisomal membranes.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060608
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  • 97
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    The plasmid-encoded killer system of Kluyveromyces lactis: A review (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 1-29 
    Details
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060102
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  • 98
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    Occurrence of peroxisomal membrane proteins in methylotrophic yeasts grown under different conditions (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 35-43 
    Details
    ISSN: 0749-503X
    Keywords: Hanseula polymorpha ; Candida boidinii ; peroxisomes ; peroxisomal membrane proteins ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have the substructure and polypeptide composition of the peroxisomal membranes in two methylotrophic yeasts in relation to different growth conditions. The results obtained that no significant ultrastructural differences existed between the membranes of variously grown cells.The presence of specific peroxisomal membrane proteins (PMPs) was studied biochemically. On sodium dodecyl sulphate-polyacrylamide gels of purified microbody membranes isolated from methanol-grown Hansenula polymorpha, prominent proteins bands were observed at 22, 31, 35, 42, 49 and 51 kD. These proteins were also present when the cells were grown in media containing ethanol and/or ethylamine. Apart from these, several other PMPs were specifically induced under these conditions, namely 24, 29, 37 and 62 kD proteins. The polypeptide composition of peroxisomal membranes from H. polymorpha was compared with that of another methylotroph. Candida biodinii. In the latter organism a specific PMP with a molecular weight of 23 kD was induced during growth on D-alanine instead of ammonium sulphate as the nitrogen source.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060104
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  • 99
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    Electronic Resource
    Comparative study on cytochrome P-450 of yeasts using specific antibodies to cytochromes P-450alk and P-45014DM (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 61-67 
    Details
    ISSN: 0749-503X
    Keywords: Cytochrome P-450 ; Lanosterol 14α-demethylase ; alkane hydroxylase ; Immunological Analysis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The occurrence of cytochrome P-45014DM(lanosterol 14α-demethylase) and cytochrome P-450alk (long-chain alkane terminal hydroxylase) in various yeast strain was determined with immunological procedures. Cytochrome P-45014DM, which is a constitutive or housekeeping enzyme playing an essential role in ergosterol biogenesis, was found in all yeast strains so far tested. Cytochromes P-45014DM from different species of yeast were immunologically different, although they may have a few common antigenic sites. In contrast, cytochrome P-450alk was detected only in the alkane-assimilating yeasts.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060107
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  • 100
    Electronic Resource
    Electronic Resource
    Bacterial plasmid pBR322 sequences serve as upstream activating sequences in Saccahromyces cerevisiae (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 221-229 
    Details
    ISSN: 0749-503X
    Keywords: Gene expression ; yeast ; vector ; gene fusion ; acid phosphatase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The expression of acid phosphatase (Apase) from PHO5 and MFα-PHO5 hybrid genes is regulated by inorganic phosphate and mating type locus respectively, as well as the PHO4 and MATα1 gene products respectively. When PHO5 and MFα-PHO5 hybrid genes were cloned in the BamHI site of the pBR322 sequence of the yeast shuttle vectors (YRp7 or YEp9T), in one orientation they were regulated normally but in the other orientation their expression was not regulated but expressed constitutively. The pBR322 sequences present upstream of the inserted genes are responsible for the constitutive expression. By replacing the PHO5 upstream activating sequences (UAS) element with pBR322 fragments, we have identified three pBR322 sequences, rom nucleotides 376 to 650, 2068 to 2116 and 2136 to 2247, which were able to promote expression of APase. A comparison of these three pBR322 fragments revealed 5′ ATCGCGCGAG 3′ and 5′ CGGTGATGNCGG 3′ to be the common sequences likely to act as USAs in Saccharomyces cerevisiae. By using synthetic oligonucleotides, it was found that both sequences are required for maximum expression of APase activity.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060307
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