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  • 1
    ISSN: 1432-1440
    Keywords: Blood Pressure ; Hypertension ; Salt ; Sodium ; Genetics ; Twin Model ; Salt Restriction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To examine the effect of genetic variance on blood pressure, sodium homeostasis, and its regulatory determinants, we studied 37 pairs of monozygotic twins and 18 pairs of dizygotic twins under conditions of volume expansion and contraction. We found that, in addition to blood pressure and body size, sodium excretion in response to provocative maneuvers, glomerular filtration rate, the renin-angiotensin system, and the sympathetic nervous system are influenced by genetic variance. To elucidate the interaction of genetic factors and an environmental influence, namely, salt intake, we restricted dietary sodium in 44 families of twin children. In addition to a modest decrease in blood pressure, we found heterogeneous responses in blood pressure indicative of sodium sensitivity and resistance which were normally distributed. Strong parent-offspring resemblances were found in baseline blood pressures which persisted when adjustments were made for age and weight. Further, mother-offspring resemblances were observed in the change in blood pressure with sodium restriction. We conclude that the control of sodium homeostasis is heritable and that the change in blood pressure with sodium restriction is familial as well. These data speak to the interaction between the genetic susceptibility to hypertension and environmental influences which may result in its expression.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 149 (1987), S. 36-42 
    ISSN: 1432-072X
    Keywords: Catabolite repression ; Genetics ; Malate dehydrogenase ; Molecular cloning ; Sequence ; CRP binding site ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The malate dehydrogenase gene of Escherichia coli, which is susceptible to catabolite and anaerobic repression, has been cloned using plasmic pLC32-38 of Clarke and Carbon (1976). The nucleotide sequence was determined of a 2.47 kbp fragment, containing the mdh structural gene. All information necessary for expression of the mdh structural gene was mapped within a 1.3 kbp SphI-BstEII fragment. Compared with the untransformed wild type, transformations with pUC19 vector, containing this fragment, gave up to 40-fold more malate dehydrogenase activity in both E. coli wild type and mdh mutant recipients. Catabolite repression was not affected in the transformants. A possible CRP binding site in the promotor region of the mdh gene provides evidence for a co-regulation with fumA gene, the structural gene of fumarase, which is also subject to catabolite repression. The structures for transcription initiation and termination were similar to those previously described for E. coli. Amino acid sequence homologies between pro- and eucaryotic malate dehydrogenases are discussed.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 146 (1987), S. 283-287 
    ISSN: 1432-1076
    Keywords: Pena-Shokeir I syndrome ; Facial anomalies ; Ankylosis ; Pulmonary hypoplasia ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two siblings whose clinical and pathologic features were consistent with the “Syndrome of camptodactyly, multiple ankyloses and pulmonary hypoplasia” originally described by Pena and Shokeir were examined at autopsy. Additional features were intrauterine growth retardation, immaturity of the central nervous system (CNS) and atrophy of skeletal muscles. Our data suggest that CNS damage may cause the complicated phenotypic abnormalities of the syndrome.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 146 (1987), S. 550-554 
    ISSN: 1432-1076
    Keywords: Epilepsy ; Genetics ; Myoclonic-astatic seizures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This paper presents case reports of patients suffering from myoclonic-astatic and stimulus-sensitive myoclonic seizures, respectively. It gives details of clinical and EEG data in the pertinent families. This is discussed in the context of controversial nosographic concepts of epilepsies with myoclonic seizures, and of the results of extensive family investigations. The findings demonstrate the decisive importance of hereditary factors in the pathogenesis of myoclonic and myoclonic-astatic epilepsy, the genetic background of which is probably polygenic.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International journal of anthropology 2 (1987), S. 141-149 
    ISSN: 1824-3096
    Keywords: Absolute finger ridge count ; Genetics ; Dermatoglyphics ; India ; Major gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to test the hypothesis of a major gene effect on absolute total finger ridge count (ATFRC), the nature of relationship between mean ATFRC and its variability was evaluated in a series of 47 population samples from India. Regression analysis showed that both the standard deviation and the coefficient of variation are significantly related to mean ATFRC, and about 35% of the variation in ATFRC is explained by the dependent variable coefficent of variation. These results support the hypothesis of a major gene effect on the trait ATFRC.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 73 (1987), S. 440-444 
    ISSN: 1432-2242
    Keywords: Secale cereale L. ; Genetics ; α-Amylase ; Isozymes ; Modifiers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fifteen inbred lines of rye, F1 and F2 progenies from crosses between lines were studied using polyacrylamide gel electrophoresis. Conventional genetic analysis of α-amylase zymograms showed that the 19 bands detected in the endosperm of germinating caryopses were controlled by three linked structural loci and one independent modifying locus, which influenced the electrophoretic mobility of isozymes. Two codominant alleles were found at the α-Amy1, α-Amy2 structural loci and the M-α-Amy modifying locus while the α-Amy3 locus had three alleles. Double-banded expression of the α-amylase alleles was probably due to the simultaneous presence of modified and unmodified forms of isozymes on the zymogram.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 69-75 
    ISSN: 1432-198X
    Keywords: Blood pressure ; Essential hypertension ; Genetics ; Epidemiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This paper presents a review of the genetic transmission of normal blood pressure and of essential hypertension. Familial aggregation of normal blood pressure has been reported in adults, in children and even in newborns. Blood pressure aggregation phenomenon, however, is the result of both a genetic component and shared environmental factors. More specific for each etiological factor were the studies of blood pressure aggregation in twins and in adopted children. Attention was focused on the Montreal Adoption Study. In essential hypertension, a Japanese study is reviewed showing the occurrence of hypertension in the offspring of hypertensive parents. The heterogeneity of essential hypertension is underlined and two of the multiple etiological factors are particularly considered for their genetic component: the response to salt intake and erythrocyte cation fluxes. The conclusion from the literature reviewed is that essential hypertension is a polygenic disease transmitted by polygenic systems.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 136-139 
    ISSN: 1432-198X
    Keywords: IgA nephropathy ; Genetics ; Complement ; C4 ; Glomerulonephritis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract C4 and factor B typing were performed in 37 pediatric patients with primary IgA nephropathy. Null alleles for C4B occurred with a frequency of 26% in patients, as compared to 15% in healthy controls (NS). The phenotype of C4B deficiency (homozygous C4B null), however, was found in 16% of patients and 4% of controls (P〈0.05). Comparison of observed C4B phenotypes with those predicted from the Hardy-Weinberg equilibrium also confirmed an excess of C4B deficiency (P〈0.0005). In contrast, there was no evidence of distortion in the frequencies of the C4A null allele or phenotype, or of the factor B alleles. The data suggest that C4B deficiency may be one of multiple interacting factors contributing to the development of this glomerulopathy.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 436-438 
    ISSN: 1432-198X
    Keywords: Alport's syndrome ; Genetics ; Heterogeneity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The pattern of inheritance in Alport's syndrome has been controversial for some time. Recent studies have clarified the mode of inheritance in this disease. Alport's syndrome is a heterogeneous disorder made up of a number of genetically distinct syndromes, with an autosomal dominant, an X-linked dominant and a rare autosomal recessive form. Clinical analysis shows that there are many distinct forms with or without nerve deafness, and with early or late occurrence of end-stage renal disease.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 397-404 
    ISSN: 1432-198X
    Keywords: Cystic kidneys ; Genetics ; Prenatal diagnosis ; Linkage studies ; Potter sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Despite the high incidence of cystic kidney diseases, affected families are not usually well informed of the inheritance of these disorders. Genetic counselling must be based on precise diagnostic criteria. Detailed information on the different types of cystic kidney disease is summarized, including clinical features, pathology, radiology, prenatal diagnosis and the risk of recurrence. In addition, a genetic interpretation is given of the Caroli syndrome, Potter sequence as well as congenital hepatic fibrosis.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 74 (1987), S. 177-187 
    ISSN: 1432-2242
    Keywords: Barley ; Grain development ; Mutants ; Ultrastructure ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Eleven Na-azide induced barley shrunken endosperm mutants expressing xenia (sex) were characterized genetically and histologically. All mutants have reduced kernel size with kernel weights ranging from 11 to 57% of the wild type. With one exception, the mutant phenotypes are ascribable to single recessive mutant alleles, giving rise to a ratio of 3∶1 of normal and shrunken kernels on heterozygous plants. One mutant (B10), also monofactorially inherited, shows a gene dosage dependent pattern of expression in the endosperm. Among the 8 mutants tested for allelism, no allelic mutant genes were discovered. By means of translocation mapping, the mutant gene of B10 was localized to the short arm of chromosome 7, and that of B9 to the short arm of chromosome 1. Based on microscopy studies, the mutant kernel phenotypes fall into three classes, viz. mutants with both endosperm and embryo affected and with a non-viable embryo, mutants with both endosperm and embryo affected and with a viable embryo giving rise to plants with a clearly mutant phenotype, and finally mutants with only the endosperm affected and with a normal embryo giving rise to plants with normal phenotype. The mutant collection covers mutations in genes participating in all of the developmental phases of the endosperm, i.e. the passage from syncytial to the cellular endosperm, total lack of aleurone cell formation and disturbance in the pattern of aleurone cell formation. In the starchy endosperm, varying degrees of cell differentiation occur, ranging from slight deviations from wild type to complete loss of starchy endosperm traits. In the embryo, blocks in the major developmental phases are represented in the mutant collection, including arrest at the proembryo stage, continued cell divisions but no differentiation, and embryos deviating only slightly from the wild type.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 74 (1987), S. 439-444 
    ISSN: 1432-2242
    Keywords: Wheat ; Callus ; Regeneration ; Tissue culture ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Calli were initiated from immature embryos of nine lines of hexaploid wheat (Triticum aestivum L. em. Thell). These were the euploid lines Chinese Spring and Cappelle-Desprez, a line of Chinese Spring ditelocentric for the long arm of 4B, four substitution lines of Chinese Spring in which chromosome 4B has been replaced by its homologues from different wheat varieties and substituted into Chinese Spring and a substitution line of Besostaya I 4B into Cappelle-Desprez. The calli from these lines were found to differ in their growth rates and morphogenic and regenerative activities. The substitution of different 4B chromosomes into Chinese Spring significantly increased morphogenesis and shoot regeneration from callus. The potential for developing wheat lines with improved culture characteristics is discussed.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Environmental biology of fishes 18 (1987), S. 249-256 
    ISSN: 1573-5133
    Keywords: Developmental rate ; Genetics ; Inheritance ; Meristic ; Salmonidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Deviations from morphological intermediacy in six first generation hybrids between three hatchery strains of rainbow trout, raised in a common environment, are reported. Hybrids have higher mean counts of four meristic characters than their maternal parental strain in a significantly greater number of cases (18 out of 24). Furthermore, eight of eleven hybrid indices are not intermediate. These results are discussed in reference to several mechanisms and models proposed to account for observed responses of meristic characters to environmental and genetic influences.
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  • 14
    ISSN: 1617-4623
    Keywords: NAD metabolism ; Regulation ; nadR ; Salmonella typhimurium ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nadR locus (99 min) controls the transcription of several genes involved with either the biosynthesis (nadAB) or recycling (pncB) of NAD in Salmonella typhimurium. Point mutations in this locus were found to cause defects either in the transport of nicotinamide mononucleotide (PnuA-), the regulation of nadAB (NadR-) or both transport and regulation (PnuA-NadR-). Deletions or insertions into nadR always resulted in the PnuA- NadR- phenotypes. Merodiploids constructed with various combiminations of PnuA-, NadR- or PnuA-NadR- strains indicate a single complementation group. The results suggest the NadR product is a bifunctional regulatory protein. Operon fusions to lacZ (nadR:: Mud1-8) were used to show that nadR is not autoregulated and is transcribed in a clockwise direction. The gene was also cloned and located within a 2 kb EcoR1-BglII fragment.
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  • 15
    ISSN: 1617-4623
    Keywords: E. coli ; Genetics ; Polysaccharide biosynthesis ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Transposon and deletion analysis of the cloned K1 capsule biosynthesis genes of Escherichia coli revealed that approximately 17 kb of DNA, split into three functional regions, is required for capsule production. One block (region 1) is required for translocation of polysaccharide to the cell surface and mutations in this region result in the intracellular appearance of polymer indistinguishable on immunoelectrophoresis to that found on the surface of K1 encapsulated bacteria. This material was released from the cell by osmotic shock indicating that the polysaccharide was probably present in the periplasmic space. Insertions in a second block (region 2) completely abolished polymer production and this second region is believed to encode the enzymes for the biosynthesis and polymerisation of the K1 antigen. Addition of exogenous N-acetylneuraminic acid to one insertion mutant in this region restored its ability to express surface polymer as judged by K1 phage sensitivity. This insertion probably defines genes involved in biosynthesis of N-acetylneuraminic acid. Insertions in a third block (region 3) result in the intracellular appearance of polysaccharide with a very low electrophoretic mobility. The presence of the cloned K1 capsule biosynthesis genes on a multicopy plasmid in an E. coli K-12 strain did not increase the yields of capsular polysaccharide produced compared to the K1+ isolate from which the genes were cloned.
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  • 16
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 1-9 
    ISSN: 0192-253X
    Keywords: T/t-complex ; LT mice ; parthenogenesis ; recombination ; gene-mapping ; primitive streak ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ovarian teratomas that result from parthenogenetic activation of oocytes provide a double tool for developmental geneties. First, they provide a way of measuring recombination between a gene and its centromere. Second, in the absence of crossing over there is the potential of producing tumors that are homozygous for genes that would be lethal in the course of in utero embryonic development. We have applied both aspects to several t- haplotypes containing different early acting t-lethal genes. In a study of 26 tumors, genotyped by Southern blot analysis of the major histocompatibility complex (MHC), we measured the distance between the centromere and the start of the t-complex as 5.6 ± 2.3 cM. We found a marked deficiency of t-homozygous genotypes among the tumors we studied, although T/T genotypes formed teratomas at levels comparable to controls. None of the lethal t-haplotypes we studied permit homozygous embryos to develop to the primitive streak stage, while T/T embryos do develop essentially normally through that stage. Thus, although the total number of tumors observed from t-bearing mice was small, the great difference in the incidence of t/t tumors versus the incidence of T/T tumors suggests strongly that the parthenogeretic embryos that convert to teratocarcinomas must first pass through some of the stages of normal early development, including the formation of three germ layers and the primitive streak.
    Additional Material: 2 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 27-34 
    ISSN: 0192-253X
    Keywords: W locus ; mouse ; chromosome 5 lethal ; implantation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A recessive lethal mutant linked to Wsh causes the death of homozygous embryos between 4.5 and 5.5 days postcoitum (pc). Histological examination of implantation sites from intercross and backcross matings indicates that homozygotes are not all evident at 4.5 days pc, when embryos have begun to form trophectoderm giant cells and primitive endoderm, but are degenerating by 5.5 days pc, with only a few primary giant cells remaining after this time. The mutants thus form blastocysts that initiate the implantation process but the inner cell mass and polar trophectoderm fail to develop further. In vitro examination and culture of blastocysts indicated that the mutant homozygotes hatch from the zona pellucida and outgrow, although they do so somewhat more slowly than normal embryos. After 3 days of culture, the inner cell masses of mutant outgrowths may be smaller than normal. Since the gene has no known heterozygous effect and the primary gene function remains unknown, the mutant has been given the provisional symbol l(5)-1 for the first lethal on chromosome 5.
    Additional Material: 3 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 179-185 
    ISSN: 0192-253X
    Keywords: differentiation ; melanogenesis ; tyrosinase ; albino ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Albino mutation in animals blocks pigmentation owing to a deficiency in tyrosinase, although it does not affect the differentiation of colorless melanocytes from the neural crest. In the albino Japanese quail (al, sex-linked), it was demonstrated that morphologically normal melanocytes differentiated from neural crest cells in culture and that these cells contained unmelanized melanosomes as expected for the mutant cells. The mutant melanocytes, however, were shown to exhibit tyrosinase activity in the Golgi-endoplasmic reticulum-lysosome region and in the Golgi vesicles. Our results seem to indicate that the mutation at the al locus affects the transport of tyrosinase from the Golgi area to melanosomes.
    Additional Material: 4 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 187-187 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 21
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. i 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 22
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 23
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 91-98 
    ISSN: 0192-253X
    Keywords: wing size ; miniature ; cell size ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To elucidate the mechanisms whereby genes and environment influence wing size, we investigated the effects of various rearing temperatures and larval crowding conditions on the wings of the mutant miniature and wild-type fruit flies. In adults we monitored wing size, cell number, wing thickness, cell density; in larval imaginal discs we looked for cell death. Cell density was inversely proportional to wing size. Of particular interest was the finding that smaller wings tend to be thicker. Electron microscope studies showed that the miniature wing layers are grossly abnormal. We hypothesize that these abnormalities are due to abnormal cell flattening of the wing epithelial cells, and we conclude that gene and environmental effects on cell flattening may be an important component in determining cell density and hence organ size.
    Additional Material: 1 Ill.
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  • 24
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 73-82 
    ISSN: 0192-253X
    Keywords: isoelectric focusing ; corticosterone ; gene assignment ; alanine transferase ; tyrosine aminotransferase ; liver cytosol ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The amount of cytosolic glucocorticoid receptor in liver of Ts18, Tsl6, and Tsl9 vs euploid mouse fetuses was studied after incubation of [3H]dexamethasone with cytosol followed by isoelectric focusing on polyacrylamide gels. In addition, corticosterone concentrations and enzyme activities of alanine aminotransferase and tyrosine aminotransferase were measured in the cytosol of the livers. The amount of glucocorticoid receptor in the cytosol fractions of the livers was always higher in the Tsl8 than in the euploid fetuses of the same litter. It was also significantly (P 〈 0.0005) higher if pooled data from different litters were analyzed. The ratio of the glucocorticoid receptor in Ts l8 vs euploid mice varied between 1.3 and 4.7, with a mean of 2.1. In contrast, the glucocorticoid receptor levels in Tsl6 and Tsl9 fetuses were not different from the corresponding euploid controls. Comparing the corticosterone levels of the three trisomies tested with the corresponding euploid fetuses, no significant differences were found, indicating that the markedly elevated cytosolic glucocorticoid receptor concentrations in Tsl8 were not due to different corticosterone levels. This finding is consistent with the assignment of the glucocorticoid receptor gene to chromosome 18 in the mouse. There was no correlation betwen glucocorticoid receptor levels and the activity of the two glucocorticoid inducible enzymes tested in the liver of mouse fetuses.
    Additional Material: 3 Ill.
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  • 25
    ISSN: 0192-253X
    Keywords: Agrobacterium insertion mutants ; hormone equilibria ; differentiation ; dedifferentiation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A series of experiments are presented that have been performed to observe the interactions between Agrobacterium tumefaciens strains mutated in the T-DNA genes involved in indoleacetic acid and cytokinin biosynthesis and several Nicotiana species and hybrids. Infections were induced on leaf cuttings of Nicotiana debneyi, N. knightiana, N. clevelandii, N. bigelovii var bigelovii, N. bigelovii var quadrivalvis, N. glauca, N. langsdorffii, the amphidiploid tumorous hybrid N. glauca × N. langsdorffii, and a nontumorous mutant of it. The effect of deletions of the Ti plasmid varied according to plant genotype. Insertion mutants in iaaM and iaaH suppressed tumor formation in N. langsdorffii, reduced it in N. bigeloviivar quadrivalvis, had no effect in N. glauca and the two amphidiploid hybrids, and promoted tumorigenesis when compared to the wild-type Agrobacterium strain B6S3 in N. bigelovii N. debneyi, and N. knightiana. The same mutations induced shoot formation in N. glauca, increased it in N. debneyi, and suppressed root formation in N. knightiana. On the other hand, an insertion mutation of the isopentenyl transferase gene (ipt-) had no effect in N. bigelovii var quadrivalvis, N. debneyi, the tumorous hybrid, suppressed tumor formation in N. langsdorffii, and inhibited it in N. glauca, the nontumorous hybrid, N. bigelovii var bigelovii, and N. knightiana. Insertion in ipt suppressed shoot formation in the nontumorous hybrid and inhibited it in the nontumorous amphidiploid and N. debneyi, while promoting root formation in N. glauca and N. debneyi.The suggestion of the existence of specific hormone equilibria necessary for the shift to each morphogenetic pattern was supported by experiments with exogenous hormone treatments of three genotypes (N. glauca, N. langsdorffii, and the nontumorous N. glauca × N. langsdorffii).
    Additional Material: 4 Tab.
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  • 26
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 99-119 
    ISSN: 0192-253X
    Keywords: Drosophila ; tissue polarity ; frizzled ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The epidermis of Drosophila has a tissue polarity that is manifested by a parallel array of polarized structures (primarily hairs and bristles). The production of normal tissue polarity requires the function of the frizzled (fz) locus. We have isolated a large number of alleles at this locus and have phenotypically characterized more than 25 of them. We have found extensive allelic variation that a previous study failed to detect. Most of the alleles fall into a hypomorphic to amorphic series. Two alleles, however, have unusual properties. These alleles, which in general are moderately strong alleles, fail to produce a rough eye phenotype that is characteristic of all the other moderate or strong fz alleles. Thus, these two alleles are tissue specific in effect. Furthermore, these two alleles also have a neomorphic or antimorphic effect on hair polarity in one region of the wing.
    Additional Material: 8 Ill.
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  • 27
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 125-133 
    ISSN: 0192-253X
    Keywords: retrovirus ; embryonal carcinoma ; embryonic gene ; DNA methylation ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Northern blot analysis and in vitro nuclear transcription assays were performed in order to clarify conflicting reports on the expression of intracisternal A particle (IAP) genes in embryonal carcinoma (EC) cell lines. Results demonstrate that post-transcriptional mechanisms control the final steady-state levels of IAP RNA in EC cells. IAP genes were further found to be undermethylated in IAP-expressing EC cell lines.
    Additional Material: 5 Ill.
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  • 28
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 151-163 
    ISSN: 0192-253X
    Keywords: positional reference ; mitotic activity ; cell identity ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The fourth chromosome mutant cubitus interruptus-Wallace(ciW) produces leg, wing, and body bristle aberrations. The effect on the wing is similar to that produced by cubitus interruptus-dominant (ciD) which also has an influence on larval segmentation indicating that it has a regulatory function. Leg morphology of haplo-4, ciW, and mosaic haplo-4:diplo-4, ci/ci+ flies was examined in an attempt to distinguish between a structural and a regulatory function by ciW. Aberrations recovered include failure of segment elongation, intersegmental gaps, duplication of bristles, and segments that are shorter than normal and of greater than normal diameter. Many of these effects are localized, suggesting that ciW may act to maintain cell positional reference. Increased local cell proliferation appears to be one manifestation of loss of the normal function.
    Additional Material: 2 Ill.
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  • 29
    ISSN: 0192-253X
    Keywords: microinjection ; familial amyloidotic polyneuropathy ; fertilized egg ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To analyze the regulation of transthyretin gene expression we have produced transgenic mice by microinjecting cloned human transthyretin genes into fertilized eggs of C57BL/6 mice. The 7.6-kilobase (kb) human transthyretin gene containing about 500 base pairs (bp) in the upstream region was used for microinjection. Seven out of nine transgenic mice had detectable amounts of human transthyretin in serum when analyzed by enzyme-linked immunosorbent assay.Transthyretin mRNA was detected in liver and yolk sac but not in other tissues including brain. The amount of mRNA was variable among transgenic mice and was about one-tenth of mouse endogenous transthyretin mRNA. Human and mouse transthyretin mRNAs were detected in liver of fetus and yolk sac at 13 days of gestation and unlike yolk sac the level of mRNA in liver increased gradually during development and reached the maximum at around 17 days of gestation. Human transthyretin was associated with mouse transthyretin to form tetramers as judged from the dilution curve of enzyme-linked immu-nosorbent assay and the spur formation in Ouchterlony assay.
    Additional Material: 8 Ill.
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  • 30
    ISSN: 0192-253X
    Keywords: lactate dehydrogenase ; spermatogenesis ; multigene enzyme family ; somatic cell hybrids ; gene mapping ; evolution ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: From the data presented in this report, the human LDHC gene locus is assigned to chromosome 11. Three genes determine lactate dehydrogenase (LDH) in man. LDHA and LDHB are expressed in most somatic tissues, while expression of LDHC is confined to the germinal epithelium of the testes. A human LDHC cDNA clone was used as a probe to analyze genomic DNA from rodent/human somatic cell hybrids. The pattern of bands with LDHC hybridization is easily distinguished from the pattern detected by LDHA hybridization, and the LDHC probe is specific for testis mRNA.The structural gene LDHA has been previously assigned to human chromosome 11, while LDHB maps to chromosome 12. Studies of pigeon LDH have shown tight linkage between LDHB and LDHC leading to the expectation that these genes would be syntenic in man. However, the data presented in this paper show conclusively that LDHC is syntenic with LDHA on human chromosome 11.The terminology for LDH genes LDHA, LDHB, and LDHC is equivalent to Ldhl, Ldh2, and Ldh3, respectively.
    Additional Material: 4 Ill.
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  • 31
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. i 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 32
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 321-337 
    ISSN: 0192-253X
    Keywords: T-DNA ; T-cyt gene ; plant promoter structure ; plant development ; plant gene regulation ; plant defense-related mRNAs ; Agrobacterium tumefaciens ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 6 Ill.
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  • 33
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 339-350 
    ISSN: 0192-253X
    Keywords: psbA gene ; DNA sequencing ; sequence homologies ; promoter ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The light-regulated chloroplast psbA gene encoding the QB protein has been cloned from rice (Oryza sativa L.), and the nucleotide sequence has been determined. Comparison of nucleotide sequences and derived amino acid sequences between species indicates a high degree of conservation of the primary structure. Comparison of promoter regions from the light-inducible chloroplast psbA, rbcL, and psaA genes indicates conservation of the prokaryotic-like promoter elements in all three genes and of a  - 21 box common only to psbA and rbcL promoter regions. No other putative regulatory signals were found based on nucleotide sequences.
    Additional Material: 3 Ill.
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  • 34
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 305-320 
    ISSN: 0192-253X
    Keywords: maize ; chlorophyll-deficient mutants ; high-chlorophyll-fluorescent mutants ; albino mutants ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Although a wide range of mutations in the nuclear genome also affect chloroplast biogenesis, their pleiotropic nature often limits their use in studying nuclear genes that regulate or facilitate chloroplast development. However, many mutations that cause a high-chlorophyll-fluorescent (hcf) phenotype exhibit limited pleiotrophy, causing the loss of functionally related sets of chloroplast polypeptides. Several hcf mutations are described that result in the loss of one specific protein complex from the thylakoid membrane. Chlorplast and cytosolic mRNAs coding for component polypeptides of the missing complex are unaffected in the mutants, suggesting that each mutation disrupts some process in the synthesis and assembly of the missing complex. Another hcf mutation causes both the loss of three protein complexes and grossly abnormal thylakoid membrane structures. The primary effect of this mutation might be in the assembly of thylakoid membranes or in the stable accumulation of the three protein complexes. Two other hcf mutations are more pleiotropic. Hcf*-38 causes a quantitative reduction of many chloroplast proteins and a reduction of some chloroplast RNAs, including several splicing intermediates. Hcf*-7 causes a major reduction of all chloroplast-encoded proteins examined. The range of pleiotropic effects of hcf mutations indicates that the mutations identify nuclear genes whose products are involved in a number of different steps in chloroplast devclopment. Because some of the mutations described have been generated by transposon insertions, they can be cloned using the transposon to identify the mutant allele.
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  • 35
    ISSN: 0192-253X
    Keywords: soybean cell suspension cultures ; phytoalexin production ; 2,4-D starvation ; chitinase ; β 1,3-glucanase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Auxin (2,4-dichlorophenoxyacetic acid) starvation of soybean cell suspension leads to the arrest of cell division after about 4 days. Readdition of 4 μM of auxin enables cells to divide again after a lag phase of 1 day. Accumulation of a well-known isoflavonoid-derived phytoalexin (glyceollin) and a highly elevated catalytic activity of two of the enzymes associated with glyceollin biosynthesis, phenylalanine ammonia-lyase and chalcone isomerase, is described. Moreover, stimulation of catalytic activity of the enzymes chitinase and β 1,3-glucanase, which are involved in plant defense against pathogens, is observed at the same time. By comparing the patterns of in vitro protein synthesis, we have identified groups of polypeptides whose synthesis is either positively or negatively regulated by auxin. Some of these polypeptides are also induced by fungal elicitor treatment. Our results provide evidence of a dual control by auxin and fungal elicitor working in an opposite manner on the inducibility of enzymes and proteins that play a role in the induced defense response of soybean.
    Additional Material: 7 Ill.
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  • 36
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 365-374 
    ISSN: 0192-253X
    Keywords: soybean ; heat-shock gene ; CaMV promoter ; plant transformation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Transcription of heat-shock protein genes in soybean can be induced by high temperature stress leading to a transient expression of heat-shock proteins. We have tested whether the replacement of a native heat-shock promoter by a viral promoter results in constitutive transcript levels of the respective gene in transgenic plants. The 35S-transcript promoter of the cauliflower mosaic virus was linked to the protein-coding region of the genomic heat-shock gene hs6831, encoding a 17.6-kD heat-shock protein of soybean. After transformation of tobacco plants with this chimeric construction using a disarmed Agrobacterium binary vector, abundant mRNA levels were detected in transgenic plants. The steady-state level of this mRNA at 25°C was equal to that generated by the native heat-shock promoter at 40°C; however, it was markedly reduced by heat shock applied to the transgenic plants. These findings suggest a sufficiently high stability of heat-shock mRNA produced at the normal growth temperature to direct constitutive expression of heat-shock proteins. The application of constitutive gene expression for the investigation of thermotolerance is discussed.
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  • 37
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 375-387 
    ISSN: 0192-253X
    Keywords: urease ; isozymes ; clones ; null mutants ; soybean ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The soybean (Glycine max [L.] Merr.) contains two urease isozymes whose expression is regulated in a tissue-specific and temporal manner. The ubiquitous urease is expressed in all tissues examined (leaf, embryo, seed coat, cell culture); the embryo-specific urease is synthesized exclusively in the developing embryo. The embryo-specific urease accumulates during seed development while the ubiquitous urease is found in highest levels during early development of both leaves and seeds. We have isolated mutants which fall in three phenotypic classes lacking one or both urease isozyme activities. Genetic analysis has thus far identified three unlinked loci which control the expression of urease(s). Genomic and cDNA clones of urease structural genes have also been recovered and we are working to assign these to genetic loci by sequence and RFLP analyses. That the ubiquitous urease isozyme is expressed in cell culture makes it possible to include cell culture in physiological and developmental studies. Additionally, we have developed direct selections for urease-negative mutants, and their revertants, in cell culture. These selections will facilitate the study of the expression of cloned urease genes in genetically transformed tissue.
    Additional Material: 4 Ill.
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  • 38
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 389-403 
    ISSN: 0192-253X
    Keywords: nuclear mutations ; chloroplast assembly ; maize ; light ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The major chlorophyll a/b light harvesting complex (LHCII) of mesophyll chloroplasts is normally assembled late during chloroplast morphogenesis. LHCII occurs at greatly reduced levels in bundle sheath chloroplasts of maize. In order to understand the normal regulatory mechanisms we are examining nuclear maize mutants that alter either (1) the assembly timing or (2) the steady state level of LHCII in mature mesophyll thylakoids. We have found a delayed greening mutant, v24 (on chromosome arm 2L), that unmasks a second unlinked locus, Mof*, that can mediate LHCII assembly timing. The polypeptides of LHCII are encoded by the nuclear multigene cab family. We find that two alleles at Mof* regulate the steady state level of cab mRNA in parallel to their effect on LHCII assembly timing: The genotype Mof*-1 Mof*-1 v24 v24 corresponds to reduced cab mRNA and late LHCII assembly timing, while Mof*-2 Mof*-2 v24 v24 corresponds to reduced cab mRNA and late LHCII assembly timing. A second group of mutations (Oy-700, pg11 and pg12 reduces LHCII levels in mesophyll thylakoids. This is the first report that pg11 and pg12) reduce the LHCII of mesophyll thylakoids. The basis of pg11 and pg12 is unknown. Mutations at the Oy locus block the chlorophyll biosynthetic enzyme, protopor-phyrin IX Mg-chelatase. Heterozygotes of the codominant mutation Oy-700 with the normal allele (Oy) have reduced LHCII. We have defined genetic backgrounds that suppress and those that do not suppress the Oy-700 Oy phenotype under certain conditions: (1) reduced light intensities (200 μE cm-2 sec-1) and/or (2) plant maturity.
    Additional Material: 7 Ill.
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  • 39
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 405-434 
    ISSN: 0192-253X
    Keywords: plant genes ; chromatin ; nucleosomes ; DNAse I-hypersensitive sites ; cytosine methylation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The nuclear DNA of eukaryotic organisms is associated with a variety of proteins, which together make up what is called “chromatin.” Chromatin serves to package all genes into higher-order structures such as nucleosomes, solenoids, and loop domains. Tight packing of a particular gene and its regulatory sequences does not allow the approach of RNA I or II polymerase proteins. Before or during the activation of such an inactive gene its chromatin has to adopt a relaxed, more “open” configuration. This altered chromatin can be probed by its higher sensitivity toward nucleases, such as DNAse I or S1 nuclease, and the appearance of DNAse I-hypersensitive sites. These sites may constitutively be present or may be induced, and they can be mapped to specific DNA sequence motifs. In many cases, such sites are delimited by non-B-DNA, notably Z-DNA, which in turn may form part of enhancer elements. The Z-DNA configuration may be induced or maintained by methylation of cytosyl residues within underlying sequences.Two plant gene model systems have been selected to probe their chromatin structure. Constitutively expressed T-DNA genes of Agrobacterium induced tobacco crown gall tumor cells have been shown to be organized in canonical nucleosomes, to be more sensitive to DNAse I than the bulk of host chromatin, and to contain a series of six constitutive DNAse I-hypersensitive sites. Inducible ribulose-1,5-bisphosphate carboxyl-ase/oxygenase small subunit (rbcS) genes of pea are rearranged into a nuclease-sensitive format upon activation by light, especially in their promoter region. The rbcS promoter harbors a series of five constitutive DNAse I-hypersensitive sites and one light-inducible site, which is surrounded by potential regulatory sequences (enhancer cores, inverted repeats). The 3′ region of rbcS genes also contains constitutive sites. Methylation/demeth-ylation of Alu I-, Fnu4H1-, HaeIII-, Sau3AI-, and Sau 96I sequences in rbcS promoters does not play any role in rbcS gene inactivation/activation.
    Additional Material: 12 Ill.
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  • 40
    ISSN: 0192-253X
    Keywords: tubulin genes ; microtubules ; Arabidopsis thaliana ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Microtubules are important components of the cytoskeleton of plant cells and play key roles in plant growth and morphogenesis. Recent molecular studies have begun to elucidate the structure and expression of plant genes coding for the major components of microtubules, α- and β-tubulin. Tubulin amino acid sequences deduced from the DNA sequences of eight higher plant tubulin genes are 79-87% homologous with constitutively expressed mammalian tubulins. The genome of the model plant system Arabidopsis thaliana contains four dispersed α-tubulin sequences and at least seven β-tubulin sequences, only two of which appear to be linked. Of the five A. thaliana genes whose expression has been analyzed, the transcripts of one α-tubulin and one β-tubulin gene are constitutively expressed in roots, leaves, and flowers. A second α-tubulin gene is expressed predominately in flowers; the transcripts of the second and third β-tubulin genes are found predominately in leaves or in roots, respectively.
    Additional Material: 7 Ill.
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  • 41
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 461-473 
    ISSN: 0192-253X
    Keywords: H3 and H4 genes ; plants ; structure ; cloning ; S1 mapping ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The general structure of the plant histone genes has been deduced from the comparison of the nucleotide sequences of ten H3 and H4 genes of maize (3 H3 and 3 H4) and Arabidopsis thaliana (2 H3 and 2 H4). The five H3 and five H4 genes encode the same proteins, respectively. The 5′-flanking regions contain the classical histone gene-specific consensus sequences. In addition, a conserved octanucleotide CGCGGATC was found in all plant histone genes at 200-250 nucleotides before the initiation codon.All six maize H3 and H4 genes are transcribed during early germination as shown by nuclease S1 mapping and reverse transcriptase primer extension experiments. The mRNA 5′-ends are located within the consensus sequence CCAA/CT/C. The 3′-ends lack the classical T-hyphenated dGC-rich palindromic structure and possess long nontranslated sequences.In both plants the multiple copies of the H3 and H4 genes are organized into multigenic families. The genes of each family show a similar proximal environment, suggesting that they originate from the duplication of a common ancestor.
    Additional Material: 7 Ill.
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  • 42
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 475-493 
    ISSN: 0192-253X
    Keywords: methylation ; Adh1 ; Zea ; Arabidopsis ; transformed DNA ; CpG-rich islands ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Higher plant DNA is extensively methylated, but the two methylated sequences (CpG and CpNpG) show different characteristics. Using sequence analysis techniques, we demonstrate that while CpG methylation follows the existing models for cytosine methylation in animals, CpNpG methylation does not. Although there is evidence to support the suggestion that the low CpG frequency has arisen from deaminational conversion of 5-methylcytosine to thymidine, there appears to be no comparable conversion of 5-methylcytosine in the CpNpG configuration. It therefore appears that between the evolution of CpG and CpNpG cytosine methylation systems, a mechanism evolved for the correction of C→T conversion, probably using the methylated strand to direct the repair in the correct direction.
    Additional Material: 6 Ill.
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  • 43
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 495-511 
    ISSN: 0192-253X
    Keywords: barley leaf development ; nuclear genes ; developmental control of transcription ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Groups of cDNA clones encoding abundant leaf proteins or derived from genes (gene families) with other features of interest have been selected from a barley leaf cDNA library. The characteriaztion of nine of the groups is summarized and includes information on the tissue specificity and light dependence of expression of their corresponding genes. Different types of control of gene expression are represented in the collection: leaf-specific expression, both stimulated and inhibited by light, constitutive expression, and expression that is maximal in one case in coleoptiles and in two cases in meristematic tissue. For the light-stimulated genes (gene families) encoding chloroplast proteins (Cab, RbcS, and plastocyanin), relative and absolute levels of messengers were determined as a function of cell age in sections of 7-day-old barley leaves grown under diurnal conditions. Key parameters of cell growth (protein, RNA, and DNA accumulation) were determined in the same leaf sections. The main conclusions of the expression studies are as follows: (1) Light is in no case a requirement for gene expression although it has significant stimulatory effect on some genes; (2) weak expression of some genes coding for chloroplast proteins was detected in the leaf-like, white coleoptiles, whereas expression in roots could not be detected; (3) The cab, rbcS, and plastocyanin genes are expressed very early during leaf cell differentiation, when the plastids morphologically are still in their amyloplast-amoeboid stages; (4) The expression of the cab, rbcS, and plastocyanin genes is not coordinated during leaf cell development.
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  • 44
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 11-15 
    ISSN: 0192-253X
    Keywords: testicular feminization ; androgen induction ; meiosis inducing substance ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The sex-linked recessive gene Tfm in the mouse produces a condition of testicular feminization (androgen insensitivity syndrome, AIS) in hemizygotes, comparable to the condition of the same name in humans. The murine mutant was originally believed to have no derivatives of the mesonephric duct system (MDS), and this absence was ascribed to dependence of these derivatives on androgens for survival. However, microscopical epi-didymides, retia testes, and vasa deferentia were identified in these animals in our laboratory. These micro-organs may play a role in meiosis induction in Tfm/Y animals. The present study was designed to determine whether survival of these organs is due to retention of an ability to respond to androgens, or whether they are unique amongst MDS derivatives in being independent of androgens.Previous studies in our laboratory demonstrated that the enzyme β-glucuronidase (βG) is androgen sensitive in the epididymis of the normal mouse. In the present investigation we used this enzyme as a marker to study androgen sensitivity in the microscopical epididymides of Tfm/Y hemizygotes and in the epididymides of control +/Y litter-mate brothers. Both mutant and control animals were studied with and without exogenous androgen stimulation.Tfm/Y hemizygotes demonstrated low levels of diffuse, cytoplasmic βG activity that appears to be unresponsive to exogenous androgen stimulation. In light of our previous studies, this distribution of βG reaction products suggests some degree of androgen sensitivity. The survival of these micro-organs and their partial androgen sensitivity may be related to the role of the MDS in inducing meiosis.
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  • 45
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 17-26 
    ISSN: 0192-253X
    Keywords: ovarian dysgenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In nonreciprocal hybrids of Chironomus thummi an environmental factor has been detected which, along with genetic factors, determines gonadal dysgenesis. Female hybrids of the cross Ch' thummi thummi ♂ ♂ × Ch. thummi piger ♀ ♀ show various degrees of rudimentary developed ovaries and sterility. The extent of these abnormalities is dependent on the developmental temperature of the hybrids. At a temperature of 21°C approximately 90% of the females are completely sterile and at 16°C only 30%. The curative effect of a temperature of 16°C on sterility occurs, however, only in those hybrid females which hatch from a specific type of egg mass (class A). Females of another type of egg mass (class B) show nearly as many dysgenic ovaries as do those developed at 21°C. At a developmental temperature of 21°C no such differentiation between the A and B class of egg masses is possible.Ovarian dysgenesis and sterility is induced during atemperature-sensitive period which extends from the beginning of embryonic development through the first two-thirds of the first larva instar stage. The abnormalities observed must be due to a failure in the early development of the germ line and are probably initiated by an inhibition of primordial germ cell divisions.
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  • 46
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 123-123 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 47
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 121-122 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 48
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 135-150 
    ISSN: 0192-253X
    Keywords: mouse ; NADP-isocitrate dehydrogenase ; electrophoresis ; gene regulation ; allele-specific expression ; heart ; kidney ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The murine “housekeeping” enzyme, cytosolic NADP-isocitrate dehydrogenase (E.C. 1.1.1.42) (genetic locus:Idh-1), exhibited a complex pattern of allele-specific expression. Protein electrophoresis on cellulose-acetate gels and determination of relative enzymatic activity by means of densitometry revealed that in heart tissue (but not liver tissue) of certain hybrid crosses the AA-homodimer was underrepresented relative to total enzymatic activity, and the degree of underrepresentation changed during development. In mixtures of homozygous tissue extracts of heart tissue (but not liver tissue) the AA-homodimer was underrepresented relative to the BB-homodimer. Relative activity of allelic isozymes varied as a function of tissue (heart versus liver), age, and the parental source of the Idh-1a allele, but did not vary as a function of sex.Allele-specific expression was also exhibited in kidney tissue of the same animals. In adult male kidney tissue extracts from heterozygotes, the AA-hornodimer was underrepresented relative to total enzymatic activity; in adult female kidney tissue extracts from heterozygotes, a more codominant phenotype was observed. Tissue extracts from immature hybrid animals exhibited a phenotype midway between the adult male and adult female phenotypes. Tissue extracts from castrated males exhibited a phenotype equivalent to that seen in females. Relative activity of allelic isozymes in kidney varied as a function of age and sex, but did not vary as a function of the parental source of the Idh-1a allele.While cytosolic NADP-IDH is a “housekeeping” enzyme, expressed in multiple tissues of the mouse, differences in the relative intensities of allelic isozyme bands provide evidence for tissue- and stage-specific regulatory variation.
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  • 49
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 165-177 
    ISSN: 0192-253X
    Keywords: embryonic antigen ; tumor mutants ; oncodevelopmental molecule ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The 63-kDa antigen recognized by the monoclonal antibody F7D6 is present in all Drosophila embryonic cells and disappears from most tissues as each one reaches its final, differentiated state. Larval tissues lose the antigen around the time of hatching, imaginal tissues lose it during metamorphosis, and germ cells lose it during gametogenesis (Bedian et al: Devel Biol 115:105-118, 1986). The nervous system and spontaneously contracting musculature of the gut and gonads are exceptions and remain antigen positive at all stages. The F7D6 antigen appears to be associated with dividing, undifferentiated cells and electrogenic cells. This prompted us to test tumors for antigen presence. We tested four different recessive mutants that give rise to four different types of tumorous transformation: the embryonic tumor Notch, several larval melanotic tumors, the imaginal disc tumor 1(2)gl, and three alleles of the ovarian tumor otu. In all cases, tumorous tissues in homozygotes contained the F7D6 antigen. The electrophoretic mobility of the antigen appeared to be unaltered in tumorous tissues compared to normal cells, but the antigen is expressed at higher levels. The antigen is found on the cytoplasmic surface of plasma membranes and appears to be a marker of undifferentiated normal and tumorous cells. Similarities and differences between the F7D6 antigen and Drosophila c-src protein are discussed.
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  • 50
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 189-194 
    ISSN: 0192-253X
    Keywords: H-Y antigen ; skin grafts ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The influence of the major histocompatibility complex (MHC) on the survival of H-Y-incompatible skin grafts in rats has been determined by challenging normal and previously sensitized females of various isogenic and congenic strains with male trunk or ear skin isografts. The MHC's influence on the potency of H-Y has also been evaluated by determining the survival of male parental strain ear skin grafts on sensitized (with F1 hybrid male cells) F1 hybrid females of two different MHC congenic strains. The results indicate that, as in mice, the MHC has a dual affect on H-Y; it is involved in determining the ability of females to respond to the antigen as well as influencing its potency.
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  • 51
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    Developmental Genetics 8 (1987), S. 207-218 
    ISSN: 0192-253X
    Keywords: chimeras ; ovotestes ; sex differentiation ; sex mosaics ; hermaphrodites ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The majority of XX ↔ XY chimeric mice develop into fertile males. The sexual differentiation of the gonads in these animals has been examined on days 12-14 postcoitum to determine if their development parallels that of normal testes. It was found that 50% of chimeric fetuses, the proportion predicted to be XX ↔ XY, had neither normal testes nor ovaries. Instead, ovotestes were present, with varying proportions of presumptive ovarian and testicular tissue. On day 12 the ovotestes were organized with testicular tissue in the central region and ovarian tissue at the craniad and/or caudad poles. In the more advanced fetuses there was evidence of regression of the ovarian portion, which would account for the testes found in adults. These results are discussed in light of current theories of sex determination and differentiation and what was previously known about gonads of sex mosaics.
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  • 52
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    Developmental Genetics 8 (1987), S. 59-60 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 53
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 35-43 
    ISSN: 0192-253X
    Keywords: development ; isozymes ; murine trisomy ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We examined developmental changes in the relative activities of three different isozyme systems: aldolase, enolase and phosphoglycerate mutase, in tissues of fetal mice with trisomy 16 and of fetal euploid littermates. We wanted to determine whether morphological abnormalities such as reduced weight and size, which are generally observed in murine trisomy, are reflected at the molecular level. Following electrophoretic separation and subsequent measurement of relative activities of enolase isozymes in brain and phospho-glycerate mutase isozymes in heart, we found no significant differences between trisomy 16 fetuses and their euploid littermates. Synthesis of liver-specific aldolase was, however, delayed in trisomy 16 fetuses.
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  • 54
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 55
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    Developmental Genetics 8 (1987), S. 45-58 
    ISSN: 0192-253X
    Keywords: white-mottled ; Malpighian tubules ; gene action ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Riboflavin deposition in organs of Drosophila hydei was studied by means of a growth test using a riboflavin-deficient strain of the fungus Aspergillus nidulans. In wild-type animals, riboflavin is deposited in Malpighian tubules (MT) and testes but not in adult eyes. Certain white (w) mutants do not contain riboflavin, whereas intermediately colored w mutants contain minor amounts of the substance. Riboflavin-containing MT cells contain special globules that can be fixed and stained with the redox dye phenazine-methosulphate. The number and size of these granules is related to growth effect and point to a role of the w locus in the intracellular deposition of riboflavin in special organs. In white-mottled (wm) position-effect variegation mutants, a significant correlation was found between the extent of variegation (percentage of yellow cells) and riboflavin content (growth effect) of the MT. However, the individual variation of cell phenotype was extremely large and exaggerated types were observed indicating “overdominance” of the rearranged w+ gene. This contradicts an unsubstantiated dogma of position-effect variegation that assumes that the affected gene simply switches between the on and off state, as is discussed.
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  • 56
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    Developmental Genetics 8 (1987), S. 83-89 
    ISSN: 0192-253X
    Keywords: chick blastula ; hypoblast-epiblast interaction ; transcriptional control ; α-amanitin ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Interaction between the epiblast and the primary hypoblast in chick blastula results in induction of the primitive streak (PS) in the epiblast. Alpha-amanitin, a specific inhibitor of poly A-containing RNA synthesis, inhibits formation of the definitive PS. This inhibition is associated with qualitative changes in the pattern of protein synthesis in the hypoblast but not in the epiblast. The protein pattern of the component areas of the epiblast shows increase in some polypeptides after treatment with α-amanitin. By contrast, α-amanitin resulted in a decrease in synthesis of several polypeptides, which are either undetectable or weakly present in the hypoblast. The α-amanitin-sensitive translational products of the embryonic genome that are observed in the hypoblast may have specific functions in the control of PS induction and stabilization.
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  • 57
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    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 58
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    Developmental Genetics 8 (1987), S. 233-247 
    ISSN: 0192-253X
    Keywords: DNA dispersion ; human β-globin ; reverse transcription ; evolution ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A human bacteriophage clone containing adult β-globin genes with four Alu sequences was microinjected to produce transgenic mice. Southern blot analysis on the spleen of a transgenic mouse revealed an unusual hybridization pattern that suggested extensive dispersion of human DNA throughout the mouse genome. This pattern was reproducible using several restriction enzymes, including a noncutting enzyme. The hybridization pattern was not observed in other tissues, and sequences were not detected in progeny using the bacteriophage probe. However, hybridization of spleen DNA of offspring against a human Alu probe revealed genetic transmission of human Alu sequences. The results suggest dispersion of microinjected Alu sequences throughout the genome.
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  • 59
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    Developmental Genetics 8 (1987), S. 281-293 
    ISSN: 0192-253X
    Keywords: mouse ; human ; cow ; maps ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Technological advances in the 1970s encouraged the mapping of homologous gene loci in different mammalian species, including mouse and man. One hundred eighty-five homologous loci have now been mapped in these two species. Conservation of linkage is sufficient to identify substantial segments of the two genomes that have been left intact since their divergence from a common ancestor. The recognition of these conserved segments allows experimental manipulation of mouse chromosomes or chromosomal regions to produce models of human chromosomal anomalies of medical importance.Comparative gene mapping has been extended beyond mouse and man and the genomes of some species, including domestic cattle, appear to be more highly conserved relative to humans than the mouse. Such species may be particularly useful in providing models of human chromosomal anomalies that cannot be duplicated in laboratory mice.
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  • 60
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    Developmental Genetics 8 (1987), S. 249-265 
    ISSN: 0192-253X
    Keywords: trisomy ; trisomy 16 mouse ; trisomy 19 mouse ; Down syndrome ; gene dosage effects ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Autosomal aneuploidy in mammals adversely affects developmental processes. In human beings, for example, trisomy 21 is the most frequent aneuploidy detected among newborns and the most common known genetic cause of mental retardation. In this review, several hypotheses are discussed that have been proposed to explain the mechanisms by which aneuploidy (especially trisomy) disrupts development. These mechanisms included specific gene dosage effects, generalized disruption of genetic homeostasis, and the influence of the parental origin of the duplicated chromosome. The availability of specific chromosomal rearrangements in mice, coupled with selective breeding schemes, permits generation of aneuploidy of specific chromosomes or chromosomal segments on controlled genetic backgrounds, thus enabling the systematic study of the causes and consequences of defined aneuploidy. Phenotypic characteristics associated with a number of specific aneuploidies in the mouse are discussed. Emphasis is placed on the effects of trisomy 16. Genetic homology between mouse chromosome 16 and human chromosome 21 has led investigators to suggest that analogous mechanisms will be responsible for the developmental abnormalities produced in these respective aneuploidies. Analysis of trisomy 16 mice from the organismal to the subcellular level has revealed a number of phenotypic characteristics (particularly neurobiologic ones) shared with human trisomy 21. The dosage effects of shared genes (or their products) may contribute to the development of these features.
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  • 61
    ISSN: 0192-253X
    Keywords: mental retardation ; Down syndrome ; cholinergic neurons ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In this study, we examined the neurochemical profiles of selected brain regions (cerebral hemispheres, diencephalon/brainstem) in fetal (day 14 to 18 gestation) trisomy 19 (Ts19) mice. The neurochemical characteristics we observed in Ts19 mice were quite different from those we observed previously in Ts16 mice. Choline acetyltransferase (ChAT) activity was reduced significantly in the cerebral hemispheres, but not in the brainstem/diencephalon, of the fetal Ts19 mouse brain, suggesting a selective vulnerability of telencephalic cholinergic neurons. Additionally, the activity of glutamic acid decarboxylase (GAD) was reduced significantly in both hemispheres and diencephalon/brainstem of late gestation Ts19 fetuses, suggesting a selective vulnerability of GABAergic neurons as well. While the levels of catecholaminergic and dopaminergic markers were reduced significantly at late gestational ages, the relative rate of turnover of dopamine (DA), measured by the ratio of DOPAC/DA, was elevated significantly in Ts19 mice. Neither reduction in the thickness of various cellular zones of the cerebral cortex nor reduced cell density of the cerebral cortex accounts for the alterations in neurochemical parameters observed in Ts19 mice. These results suggest that the effects of the triplication of specific genes on the respective chromosomes, rather than a generalized disruption of developmental homeostasis resulting from extra chromosomal material, may produce selective alterations in neurochemical and neuroanatomical markers observed in these two mouse trisomies.
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  • 62
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    Developmental Genetics 8 (1987), S. 295-304 
    ISSN: 0192-253X
    Keywords: sequence ; cDNA ; fetal pig ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A cDNA clone of porcine alpha1 acid glycoprotein (α1AGP) has been isolated and sequenced. Sequence homologies between porcine, human, and rat indicate that porcine α1AGP is similar in structure to the rat and human proteins. RNA blots from days 40, 60, 80, and 110 fetal, newborn, and adult livers showed that α1AGP mRNA is relatively abundant throughout fetal development, particularly at the later stages and in the newborn; there is a rapid decline in abundance following birth. From birth to 3 days of age, there is a three- to four-fold decline in abundance, and α1AGP mRNA is approximately 100 times less abundant in the adult liver than in that of perinatal pigs. Southern blots showed that α1AGP is probably a single-copy gene. The isolation of a cloned cDNA for porcine α1AGP provides a tool to investigate the molecular mechanisms involved in the developmental regulation of the gene and to correlate changes in gene expression during development with fetal growth and well being.
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  • 63
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    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 64
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    Yeast 3 (1987) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 65
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    Yeast 3 (1987), S. 187-200 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 2 Ill.
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  • 66
    ISSN: 0749-503X
    Keywords: Cellulases ; Endoglucanases ; Trichoderma reesei ; Saccharomyces cerevisiae ; Cellulolytic yeast ; secretion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cDNA copies of the two endo-β-1,4-glucanase genes, egl1 and egl3, from the filamentous fungus Trichoderma reesei were expressed in yeast Saccharomyces cerevisiae under the control of the yeast phosphoglycerate kinase gene promoter. Active EGI and EGIII enzyme was produced and secreted by yeast into the growth medium. The recombinant EGI enzyme was larger and more heterogeneous in size than the native enzyme secreted by Trichoderma, due to differences in the extent of N-glycosylation between these two organisms. The morphology of the yeast cells producing EGI or EGIII was clearly different from control strain.
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  • 67
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    Yeast 3 (1987), S. 71-76 
    ISSN: 0749-503X
    Keywords: OFAGE ; X-ray damage ; DNA repair ; Saccharomyces cerevisiae ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Orthogonal field alternation gel electrophoresis (OFAGE) allows separation of DNA molecules in the size range of 200 kb to 3000 kb. These sizes encompass the chromosome sizes of the genome of Saccharomyces cerevisiae. Using this technique, we have found that yeast cells exposed to X-rays generate a smear of DNA fragments corresponding to the products of random, independent double strand breaks, and that the bands corresponding to unbroken chromosomes decrease in intensity in direct proportion to chromosome size. If exposed wild type cells are permitted time to repair (5 h at 30°C on YEPD), the fragments partially disappear and the chromosome bands reappear, although at less than normal intensity. In certain radiation-sensitive mutants (rad51, rad52 and rad54), the fragment smear appears following X-ray exposure but no repair of broken chromosomes occurs. In fact, loss of the fragments occurs; this could appear as partial repair using other procedures.
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  • 68
    ISSN: 0749-503X
    Keywords: Cyclic AMP ; nitrogen limitation ; resting state ; cell cycle ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have identified a mutation called rcal (for rescue by cAMP) which allows adenylate cyclase-deficient mutants to divide in the presence of cAMP. We took advantage of this rcal mutation to study the effect of externally added cAMP on the onset of the resting state when cells are starved for ammonium. We measured the resistance of the cells to zymolyase treatment as a parameter of the resting state. We observed that the onset of the resting state is reversibly blocked by cAMP. This inhibitory effect of cAMP is discussed together with the cAMP control of the start. This leads us to propose a model in which the cAMP level, controlled by the availability of nutrients, should trigger the choice between the entry of the cell into the resting state and the initiation of a new division cycle.
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  • 69
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    Yeast 3 (1987), S. 95-105 
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; tryptophan accumulation ; genetic engineering ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Plasmid pME559, carrying all five yeast TRP genes, was constructed. This plasmid is a yeast/Escherichia coli shuttle vector based on pBR322 and 2 μm-DNA sequences derived from plasmid pJDB207. We studied in yeast (i) the stability of the plasmid under selective and non-selective conditions, (ii) expression of all five TRP genes and (iii) tryptophan accumulation in yeast transformants. These studies were conducted in comparison with an earlier construction, pME554, which differs from plasmid pME559 in the expression of the TRP1 gene and which carries the TRP2 wild type instead of the TRP2fbr mutant allele. For stable maintenance of the plasmids in yeast a selection was necessary. Plasmid pME559 displayed normal expression of all TRP genes, and enzyme levels on average 23-fold higher than in the wild type strain were found. In comparison, the maximal tryptophan flux observed in such a plasmid-carrying strain was about ten-fold higher than the maximal flux capacity in the wild type strain.
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  • 70
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    Yeast 3 (1987), S. 117-129 
    ISSN: 0749-503X
    Keywords: Killer ; virus-like particles ; nucleotides ; pyrophosphatase ; RNA polymerase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The intracellular killer virions of yeast co-purify with an RNA polymerase activity which catalyzes the synthesis of fulllength transcripts of the two viral genomic double-stranded RNA segments. This polymerase utilizes ribonucleoside diphosphates or triphosphates as substrates. The virions have other associated nucleotide-metabolizing enzyme activities, including nucleoside diphosphate kinase, adenosine monophosphate kinase, and nucleoside triphosphate phosphotransferase, an activity which catalyzes the exchange of gamma-phosphate from any ribonucleoside triphosphate with any ribonucleoside or deoxyribonucleoside triphosphate. The purified virions also contain an inorganic pyrophosphatase activity. These enzymes may allow the virus to utilize nucleotide pools distinct from those utilized in host cell transcription.
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  • 71
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    Yeast 3 (1987) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 72
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    Yeast 3 (1987), S. 149-160 
    ISSN: 0749-503X
    Keywords: DNA repair ; RAD2 ; Saccharomyces ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cloned RAD2 gene of S. cerevisiae was tailored into regulatable expression vectors for overexpression of Rad2 protein in E. coli and in yeast. In E. coli both Rad2/β-galactosidase fusion protein and native Rad2 protein are insoluble, but are extractable with 1% Sarkosyl. In yeast some of the overexpressed native Rad2 protein is also insoluble; however, soluble protein is readily detected by immunoblotting with Rad2-specific antibodies. All forms of the protein detected in transformed or untransformed yeast cells and the insoluble species in E. coli migrate in denaturing polyacrylamide gels with an apparent molecular weight considerably larger than the size predicted from the sequence of the RAD2 coding region. This property is not the result of post-translational glycosylation detectable by binding of concanavalin A, or of phosphorylation of the protein. Overexpression of the RAD2 gene is toxic to yeast. Transformed yeast cells grow much more slowly than untransformed controls and when yeast transformants are serially propagated cultures show considerable colony heterogeneity and concomitant selection for rapidly growing variants which express less Rad2 protein. Antisera raised against Rad2/β-galactosidase fusion protein expressed in E. coli do not cross-react with Rad1, Rad3 or Rad10 protein in crude extracts of yeast, nor with purified E. coli UvrA, UvrB or UvrC proteins.
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  • 73
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; mitochondria ; cAMP-dependent protein kinase ; submitochondrial localization ; topology ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We describe the identification and submitochondrial localization of four protein kinases and of their target proteins in derepressed yeast mitochondria. The activity of one of the kinases depends on the presence of cyclic AMP (cAMP). It is soluble and localized in the mitochondrial intermembrane space. Its natural target is a polypeptide of 40 kDa molecular mass, which is bound to the inner membrane. Besides this natural target this kinase phosphorylates acidic heterologous proteins, like casein, with high efficiency. The other protein kinases identified so far are cAMP-independent. At least one is localized in the matrix having its natural substrates (49 and 24 kDa) in the same compartment. Two others are firmly bound to the inner membrane phosphorylating target proteins in the inner membrane (52·5 kDa) and in the intermembrane space (17·5 kDa), respectively.
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  • 74
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    Yeast 3 (1987) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 75
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 76
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    Yeast 3 (1987), S. 223-232 
    ISSN: 0749-503X
    Keywords: Ethanol tolerance ; membrane fluidity ; fermentation ; Saccharomyces ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Evidence is presented for an exponential increase in yeast plasma membrane fluidity (as meaured by pasive permeability to acetic acid) with ethanol concentration. The role of adaptation of yeast cells to ethanol can be seen in the existence of a threshold concnetration before the onset of an observed fluidizing effect. The physiological state of the yeast cells is also demonstrated to influence the sensitivity of the membrane to fluidizatio by ethanol. On the basis of these results, the concept that increased fluidity is an adaptive response conferring ethanol tolerance is disputed. An alternative hypothesis, namely that the observed increase in fluidity is the net result of a number of more fundamental changes, is presented to explain the observed effects.
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  • 77
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    Yeast 3 (1987), S. 1-4 
    ISSN: 0749-503X
    Keywords: Cell cycle ; sporulation ; meiosis ; nuclear division ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cell division age dependency of sporulation was investigated in a diploid strain of Saccharomyces cerevisiae (19el) which undergoes a single equational nuclear division during sporulation with consequent formation of asci containing two uninucleate diploid spores (apomictic dyads). Under modified nutritional conditions which partially restore meiosis and hence normal tetrad formation, newly formed (age 0) daughter cells were observed to be capable of formation of apomictic dyads but not of meiotic tetrads. Even under conditions in which only apomictic dyads developed, approximately 20% of the asci resulted from differentiation of newborn ‘inexperienced’ cells. Thus, the data indicated production of at least one bud to be a prerequisite for meiosis but not for apomixis; however, occurrence of at least one complete mitotic cell division cycle was evidently insufficient for the morphogenetic switch from diploid to haploid spore formation, since older cells bearing several bud scars often underwent apomictic dyad development, and some produced no spores.
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  • 78
    ISSN: 0749-503X
    Keywords: Zygosaccharomyces ; weak-acid resistance ; intracellular pH ; yeast ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Weak acids and hydrogen ions in different concentration combinations affect the intracellular pH value (pHi) of Zygosaccharomyces bailii. The lowest pHi value measured was not at the most extreme, but at intermediate conditions of inhibition. Proton and organic-acid ejection, on a cell volume basis, is greater in cells grown under inhibitory conditions and is stimulated by weak acids, whilst in cells not grown under inhibitory conditions acid efflux is lower and is depressed by weak acids; this may be important in the maintenance of tolerable pHi values in the presence of weak acids. The concentration of benzoic acid measured internally is identical to the value expected from its pK, external pH and pHi. Addition of fructose to starved cells causes both a decreased pHi and a concomitant efflux of previously loaded benzoic acid, quantitatively in accord with the shift in equilibrium of the freely permeable undissociated acid. There is no evidence that weak acids are actively extruded. Protoplast volume also varies with hydrogen-ion and weak-acid concentration and this too may play a role in intracellular pH maintenace.
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  • 79
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 80
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    Yeast 3 (1987), S. 62-62 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 81
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    Yeast 3 (1987) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 82
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 209-221 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 2 Tab.
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  • 83
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 201-206 
    ISSN: 0749-503X
    Keywords: Flocculation ; yeast ; shaking ; activation-energy ; surface-charge ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Flocculent yeast cells have an absolute requirement for mechanical energy input in order for flocculation to occur. Flocculation is arrested by cessation of energy input. The initial rate of flocculation increases as the square of the cell concentration. There is a minimum shaking speed to initiate flocculation and thereafter the initial rate of flocculation increases exponentially with the shaking speed. The minimum shaking speed for flocculation to occur increases with pH value. Activation energy for flocculation, derived from Arrhenius-like plots, varies with pH value. We propose that activation energy is required to overcome mutual repulsion between charged yeast cells and allow flocculent bonds to be formed.
    Additional Material: 6 Ill.
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  • 84
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 255-262 
    ISSN: 0749-503X
    Keywords: Yarrowia lipolytica ; isocitrate lyase ; structural gene ; gene map ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The gene ICL1 codes for the tetrameric enzyme isocitrate lyase of Y. lipolytica. Twenty icl1- alleles have been analysed for their reversion frequency, their interallelic complementation pattern, and the position of the corresponding mutation site on the fine structure map of the gene ICL1. One intragenic temperature-sensitive revertant of the allele icl1D-39 was isolated, which expressed a thermolabile enzyme. In spite of the fact that no nonsense mutations have been detected, the direction of transcription of the gene ICL1 was inferred from the localization of a linked cis-dominant regulatory mutation site. The size of the mitotic map of this gene suggests that recombination frequency in Y. lipolytica is lower than in Saccharomyces cerevisiae.
    Additional Material: 4 Ill.
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  • 85
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 273-273 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 86
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 263-270 
    ISSN: 0749-503X
    Keywords: Lodderomyces elongisporus ; Rhodotorula gracilis ; Saccharomyces cerevisiae ; accumulation ratio ; membrane transport ; suspension density ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The previously described effect of cell suspension density on metabolic and transport phenomena in yeast, apparently caused by inhibition by dissolved carbon dioxide, is also observed with the accumulation ratio of both sugars and amino acids where not only a kinetic but also an energetic factor comes into play. Unlike all previously measured metabolic and transport parameters, the dependence of the accumulation ratio on suspension density is not monotonic but shows a pronounced maximum in the range of 4-8 mg dry wt/ml, depending on yeast species and on cultivation conditions. In Rhodotorula gracilis and in Lodderomyces elongisporus it is not due to CO2 but is semiquantitatively related to the proton-motive force across the plasma membrane as well as to the intracellular ATP content. It is observed both in oxygen and in argon, over a wide range of pH values and of temperatures, but it is suppressed by metabolic inhibitors. It is expressed only in a range of transported solute concentrations between about 0·1 and 10 mM.
    Additional Material: 5 Ill.
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  • 87
    ISSN: 0749-503X
    Keywords: Cell cycle genes ; genetic mapping ; Saccharomyces ; OFAGE ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: CDC3, CDC25 and CDC42 were localized to chromosome XII by hybridizing the cloned genes to Southern blots of chromosomes separated by orthogonal-field-alternation gel electrophoresis. Meiotic tetrad analyses further localized these genes to the region distal to the RDN1 locus on the right arm of the chromosome. The STE11 gene, which had previously been mapped to chromosome XII (Chaleff and Tatchell, 1985), was found to be tightly linked to ILV5. The data suggest a map order of CEN12-RDN1-CDC42-(CDC25-CDC3)-(ILV5-STE11)-URA4. Certain oddities of the data set raise the possibility that there may be constraints on the patterns of recombination in this region of chromosome XII.
    Additional Material: 2 Ill.
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  • 88
    ISSN: 0749-503X
    Keywords: Pichia pinus ; alcohol oxidase ; catabolite repression ; metabolic regulation ; methanol ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effect of various carbon compounds on the synthesis of alcohol oxidase in a medium with methanol was studied in the wild type strain of Pichia pinus as well as in gcr1 and ecr1 mutants defective in glucose and ethanol repression of methanol metabolic enzymes, respectively. Compounds repressing the synthesis of alcohol oxidase in the wild type strain were divided into four groups. Repression of alcohol oxidase by compounds of the first group (glucose, fructose, mannose, galactose, L-sorbose and xylose) was impaired only in the gcr1 mutant and that by compounds of the second group (ethanol, acetate, 2-oxoglutarate and erythritol) only in the ecr1 mutant. Repression by compounds of the third group (malate, dihydroxyacetone) was not impaired in both these regulatory mutants and that by compounds of the fourth group (succinate, fumarate, L-arabinose, sorbitol, salicin, xylitol and cellobiose) was partially reduced in both gcr1 and ecr1 strains.Mutation gcr1 causes a significant decrease in phosphofructokinase activity. It also led to a six- to seven-fold increase in intracellular pools of glucose-6-phosphate and fructose-6-phosphate and to a two-fold decrase in the intracellular pool of fructose-1,6-bisphosphate. In ecr1 strains, a decrese in 2-oxoglutarate dehydrogenase activity accompanied by an increae in activities of NAD- and NADP-dependent isocitrate dehydrogenases and NAD- and NADP-dependent glutamate dehydrogenases was demonstrated. The intracellular pool of 2-oxoglutarate was increased 2·5-fold in ecr1 strains. Genes GCR1 and ECR1 are not linked.The mechanisms of catabolite repression of alcohol oxidase in methylotrophic yeasts are discussed.
    Additional Material: 4 Tab.
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  • 89
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 90
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 5-9 
    ISSN: 0749-503X
    Keywords: Schizosaccharomyces pombe ; sterile mutants ; ste genes ; protoplast fusion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In previous experiments of Girgsdies (1982), eight sterile (ste) mutants of Schizosaccharomyces pombe did not sporulate when fused with h+ or h- protoplasts. We succeeded in achieving sporulation with these mutants. Two hitherto unknown ste genes, ste7 and ste8, were found.
    Additional Material: 3 Tab.
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  • 91
    ISSN: 0749-503X
    Keywords: Yeast protein map ; carbon metabolism machinery ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Using a modification of the basic two-dimensional polyacrylamide gel electrophoresis technique, we have undertaken a systematic identification of the polypeptides of the protein map of Saccharomyces cerevisiae corresponding to components of the carbon metabolism machinery. To the previous location of nine glycolytic enzyme polypeptides on the yeast protein map we add the location of 23 polypeptides. Ten of them were identified as corresponding to cytoplasmic enzymes of the carbon metabolism machinery and 13 were characterized as mitochondrial proteins. The criteria used to establish the identification of these polypeptides spots include migration with purified proteins, immunodetection, overproduction by plasmid-carrying strains and physiological behaviour.
    Additional Material: 4 Ill.
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  • 92
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 33-42 
    ISSN: 0749-503X
    Keywords: Yeast ; acid phosphatase ; gene regulation ; upstream activating sequences ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To identify the sequences involved in the regulation of the yeast acid phosphatase gene (PHO5) we constructed a series of hybrid promoters. Increasing lengths of 5′-flanking sequences of the PHO5 gene were placed in front of the TATA-box of constitutively expressed acid phosphatase gene (PHO3).The PHO5/PHO3 promoter constructions were used to replace the entire PHO5, PHO3 gene cluster on chromosome II. Depending on the length of PHO5 5′-flanking sequences present the PHO3 gene driven by the hybrid promoter could now be derepressed in response to inorganic phosphate (low Pi) exactly as the PHO5 wild type gene. A critical regulatory element was located between position -402 to -351 (upstream from ATG) and sequences further downstream (from -351 to -300) could increase transcriptional activation. The transcription levels of PHO3 were determined by northern blot analysis, under repressed (high Pi) and derepressed (low Pi) conditions which was paralleled by an increase in extra-cellular acid phosphatase activity. Fully regulated promoter hybrids showed a 40-fold induction of mRNA levels, comparable to wild type PHO5 promoter. S1-nuclease protection experiments revealed that the PHO5 5′-flanking sequences, placed in front of PHO3, did not change the PHO3 transcription initiation site/s.
    Additional Material: 7 Ill.
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  • 93
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 43-49 
    ISSN: 0749-503X
    Keywords: Heterologous gene expression ; Hepatitis B ; protein estimation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Purified recombinant hepatitis B surface antigen separated on polyacrylamide gels in the presence of sodium dodecyl sulphate has a very low staining index with Coomassie blue relative to a number of standard proteins. In contrast the protein stains better than average with silver nitrate. This property has been used to develop a semi-quantitative method of estimation of recombinant surface antigen in extracts of Saccharomyces cerevisiae producing this protein. The method can be used to follow purification protocols. It is quick, simple and since it measures the surface antigen biochemically, is independent of the aggregation state or conformation of the protein, a factor which can affect enzyme-linked immunoassays which rely on antigen-antibody interactions.
    Additional Material: 3 Ill.
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  • 94
    ISSN: 0749-503X
    Keywords: Genome organization ; Saccharomyces cerevisiae ; chromosome I ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: MAK16 is an essential gene on chromosome I defined by the thermosensitive lethal mak16-1 mutation. MAK16 is also necessary for M double-stranded RNA replication at the permissive temperature for cell growth. As part of an effort to clone all the DNA from chromosome I, plasmids that complemented both the temperature-sensitive growth defect, and the M1 replication defects of mak16-1 strains were isolated from a plasmid YCp50: Saccharomyces cerevisiae recombinant DNA library. The two plasmids analysed contained overlapping inserts that hybridized proportionally to strains carrying different dosages of chromosome I. Furthermore, integration of a fragment of one of these clones occurred at a site linked to ade1, confirming that this clone was derived from the appropriate region of chromosome I. An open reading frame adjacent to MAK16 potentially coding for a 468 amino acid protein was defined by sequence analysis. 185 amino acids of this open reading frame were replaced with a 1·2 kb fragment carrying the S. cerevisiae URA3 gene by a one-step gene disruption. The resulting strains grew at a rate indistinguishable from the wild type at 20°C, 30°C, or 37°C, but could not grow at 8°C. The deleted region is thus essential only at 8°C, and we name this gene LTE1 (low temperature essential).
    Additional Material: 4 Ill.
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  • 95
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 63-70 
    ISSN: 0749-503X
    Keywords: Antibodies ; immunofluorescent labelling ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the course of making antibodies against various yeast (S. cerevisiae) proteins, we have noted that it is common to observe reactivity of rabbit sera with a number of extraneous bands on Western transfers of yeast proteins. The pattern of reactive bands can change within a period of weeks, even when the rabbit has not been injected with antigen. A simple method of affinity purification, using antigen bound to nitrocellulose, is employed to remove the reactivity with these extraneous bands from immune sera. The importance of affinity purification is demonstrated by our attempts to immunolocalize a 55 kd yeast protein (p55). Immune serum stains yeast cells to give a striking pattern of spots and blotches not seen with preimmune serum. However, affinity purification of anti-p55 antibody shows that this pattern is not due to staining by anti-p55 antibody; rather the pattern is due to staining left in the serum depleted of anti-p55 antibody.
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  • 96
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 77-84 
    ISSN: 0749-503X
    Keywords: Microbodies ; Saccharomyces cerevisiae ; oleic acid ; β-oxidation ; catalase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The development of microbodies in the yeast Saccharomyces cerevisiae was studied in response to different conditions of growth. Various strains of S. cerevisiae were investigated, using cells from the exponential growth phase on glucose as an inocullum in all transfer experiments. Electron microscopy, including serial sectioning, revealed that these cells generally contained one to four small microbodies which were localized in the vicinity of the cell wall and characterized by the presence of catalase. Transfer of these glucose-grown cells into media supplemented with various compounds known to induce microbody proliferation in other yeasts - i.e. uric acid, alkylated amines, amino acids, C2-compounds such as ethanol or acetate, in the presence or absence of compounds that induce oxygen radical formation - did not result in a significant change in the number of microbody profiles observed. Marked microbody proliferation was, however, observed after a shift of cells into media containing oleic acid and was associated with the induction of activities of β-oxidation enzymes. In addition, catalase and isocitrate lyase were present in enhanced levels. Kinetic experiments suggested that these microbodies developed from those originally present in the inoculum cells. In thin sections up to 14 microbody profiles were occasionally observed, often present in small clusters. Their ultimate volume fraction amounted to 8-10% of the cytoplasmic volume.
    Additional Material: 8 Ill.
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  • 97
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 107-115 
    ISSN: 0749-503X
    Keywords: DNA replication ; ARS elements ; histone genes ; Saccharomyces cerevisiae ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have previously identified an autonomously replicating segment (ARS) near the 3′ end of the histone H4 gene at the copy-I H3-H4 locus. We have now searched for additional autonomously replicating segments and sequences homologous with the ARS core consensus sequence near the copy-II histone H4 gene and both of the histone H3 genes. No new ARS elements were identified by functional cloning assays. However, several matches to the ARS core consensus element were found within the DNA sequencs of the copy-I and copy-II genes. An exact match to the ARS core consensus was identified in the region downstream from the copy-I histone H3 gene and a set of sequences with weak homology was also locatd within the copy-II region. However, restriction fragments including these sequences did not demonstrate ARS activity on a plasmid in transformed cells.
    Additional Material: 3 Ill.
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  • 98
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 131-137 
    ISSN: 0749-503X
    Keywords: Transformation ; Saccharomyces ; plasmid ; DNA uptake ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have studied the mechanism of DNA transformation of whole yeast cells in Saccharomyces cerevisiae with particular emphasis on the role of the cell wall complex in DNA uptake. Two new aspects of the process have been investigated in order to evaluated its specificity. Such aspects are: (i) effect of monovalent vs. divalent cations during incubation with the transforming DNA and (ii) timing of DNA adsorption and uptake. We found that the specificity for cation requirement is a strain-dependent characteristic influenced by the presence of transforming DNA in the cell suspension. This finding is supported by reports from several laboratories that some yeast strains show mutually exclusive transformability with monovalent vs. divalent cations. While irreversible adsorption of plasmid DNA molecules is induced by both heat shock and polyethylene-glycol(PEG), DNA uptake seems to occur only after the removal of PEG. In the course of this study we have developed a new, alternative method of whole cell DNA transformation with CaCl2 able to transform strains that do not respond to other methods.
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  • 99
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 3 (1987), S. 139-148 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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