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  • 1990-1994
  • 1985-1989
  • 1980-1984  (41)
  • 1982  (41)
  • Genetics
  • 1
    ISSN: 1432-2072
    Keywords: Ethanol sensitivity ; Barbiturate sensitivity ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two lines of rats, ‘least affected’ (LA) and ‘most affected’ (MA), had been selectively bred for their differential sensitivity to ethanol. Both males and females of the LA strain were observed to be less sensitive than their MA counterparts to the acute hypnotic and motor-impairing effects of ethanol. However, a lower ethanol metabolic rate of the MA males suggests that both CNS and metabolic factors contribute to their enhanced sensitivity to ethanol. By contrast, no differences were observed between the LA and MA males with respect to the hypnotic and subhypnotic effects of pentobarbital or to the clearance of this drug. MA females were more sensitive only to the hypnotic effects of pentobarbital, probably because of a smaller apparent volume of distribution. No strain difference was observed in the hypnotic effect or clearance of barbital. These observations suggest that, in spite of a differential sensitivity to ethanol, the LA and MA lines do not differ in their response to the barbiturates tested.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 139 (1982), S. 298-303 
    ISSN: 1432-1076
    Keywords: Thanatophoric dysplasia ; Cloverleaf-skull ; Dwarfism, neonatal ; Histomorphology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The radiologic and morphologic features of thanatophoric dysplasia with cloverleaf-skull could be demonstrated in a neonate who died from asphyxia shortly after birth. Occipital bone hemangiomatosis, a typical histomorphologic finding in cloverleaf-skull, is reported for the first time in a thanatophoric dwarf. Our investigations and the discussion of 26 observations of thanatophoric dysplasia with cloverleaf-skull reported since 1967 do not yet allow complete understanding of the pathogenetic relationship of both malformations. They serve, however, to elucidate some crucial unanswered questions which it is suggested should be studied in future observations of thanatophoric dysplasia with cloverleaf-skull.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 232 (1982), S. 137-155 
    ISSN: 1433-8491
    Keywords: Unipolar depression ; Neurotic-reactive depression ; Sporadic depression ; Morbidity risk ; Genetics ; Monopolare Depression ; Neurotisch-reaktive Depression ; Sporadische Depression ; Morbiditätsrisiko ; Genetik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Sechzig (23 Männer und 37 Frauen) monopolare Patienten und 67 (25 Männer und 42 Frauen) Patienten mit einer neurotisch-reaktiven Depression, fortlaufend in die Psychiatrische Klinik der Universität Umeå aufgenommen, nahmen an einer Familienstudie mit dem Ziel das Morbiditätsrisiko (MR) für psychiatrische Erkrankungen unter Verwandten 1. Grades (n=437) zu identifizieren, teil. Außer dem in Umeå zu Forschungszwecken angewandten Klassifikationssystems, wurden die Patienten auch gemäß dem ICD-9, DSM-III, Ausbruchsalter (unter bzw. über 40 Jahre alt) und der Winokurschen Klassifikation der primären affektiven Erkrankungen eingeteilt. In diesem Artikel sind jedoch nur die Ergebnisse hinsichtlich der Umeå- und der Winokurschen Klassifikation wiedergegeben. Neunzig Prozent der Patienten erfüllten Kendells Kriteria für Depressionen zur Zeit der Untersuchung, wohingegen der Rest sich in der Besserungsphase befand. Die Diagnosen der Sekundärfälle wurden ohne Kenntnis der Diagnosen der Probanden gestellt. Unter den Verwandten der monopolaren Probanden wurden nur 2 sekundäre Fälle von bipolaren affektiven Erkrankungen gefunden — einer unter Eltern und einer unter Geschwistern (MR% 1,1 bzw. 0,6). Das Gesamtmorbiditätsrisiko für affektive Erkrankungen (MR% 22,8 unter Eltern und 15.5 unter Geschwistern) erwies sich höher als in früheren Untersuchungen. Auch in den Familien der neurotisch-reaktiven Patienten lag das Morbiditätsrisiko für manisch-depressive Erkrankungen sehr niedrig (MR% 1,0 unter Eltern und 0,7 unter Geschwistern), das Gesamtmorbiditätsrisiko für affektive Erkrankungen dagegen stellte sich als überraschend hoch (12,1% unter Eltern bzw. 6,7% unter Geschwistern) heraus. In keiner der beiden Gruppen zeigte sich ein erhöhtes Risiko für Schizophrenia oder Alkoholismus unter den Verwandten. Bei der Aufteilung der Verwandten nach dem Geschlecht ergab sich, außer für Alkoholismus, der häufiger unter männlichen Verwandten auftrat, kein eindeutiger Unterschied bezüglich des Morbiditätsrisikos, nachdem die Väter und Brüder mit den Müttern und Schwestern verglichen worden waren. Vorläufige Ergebnisse unter Verwandten zweiten Grades deuten darauf hin, daß sekundäre Fälle von affektiven Erkrankungen unter Verwandten zweiten Grades von solchen Patienten auftreten, die gemäß der Winokurschen Klassifikation als an einer „sporadischen Depression“ leidend, bezeichnet werden können.
    Notes: Abstract Sixty unipolar (23 male and 37 female) patients and 67 patients (25 male and 42 female) suffering from a neurotic-reactive depressive disorder, consecutively admitted to the Department of Psychiatry of Umeå University have participated in a family study aimed at identifying morbidity risks for psychiatric illnesses among first degree relatives (n=437). Besides the classification of affective disorders used in Umeå for research purposes the patients have been classified, according to the ICD-9, DSM-III, age at onset (below or above 40 years), and the Winokur's classification of primary affective disorders. However, only the findings regarding the Umeå classification and the Winokur's classification are given in the present article. Of the patients 90% fulfilled Kendell's criteria for depression at the time of the investigation whereas the others were in a phase of remission when studied. The diagnosis of secondary cases were made without knowledge of the diagnoses of the probands. Among relatives of unipolar probands only two secondary cases of bipolar affective disorder were found—one among parents, and one among siblings (MR% 1.1 and 0.6 respectively). The overall morbidity risk for affective disorders (MR% 22.8 among parents and 15.5 among siblings) proved to be higher than in previous studies. In the families of neuroticreactive patients the morbidity risk for bipolar affective disorders was also very low (MR% 1.0 among parents and 0.7 among siblings), whereas the overall MR% for affective disorders proved to be surprisingly high (12.1 among parents and 6.7 among siblings). No increased risk for schizophrenia or alcoholism was found among the relatives of either group. When the relatives were divided according to their sex no clear-cut difference in morbidity risk emerged when fathers and brothers were compared with mothers and sisters but alcoholisms occurred more frequently in male relatives. Preliminary findings in second degree relatives suggest that secondary cases of affective disorders might occur among second degree relatives of patients classified as suffering from “sporadic depression” according to Winokur's classification.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical biology 15 (1982), S. 65-77 
    ISSN: 1432-1416
    Keywords: Epidemics ; Genetics ; Continuous models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Mathematics
    Notes: Abstract Continuous deterministic models are used to investigate the relationship between the epidemiology of endemic infectious disease and the genetics of natural selection in the host population when a specific genetic locus controls susceptibility to disease under a variety of circumstances. One locus, two allele genes are considered in the contexts of haploid and diploid host populations while the agent of infection is assumed to be invariant. It is found that polymorphic equilibria exist and are stable for certain parameter combinations in each of the cases studied. The equilibrium levels of gene frequencies and disease prevalence depend on both genetic and epidemic factors.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 62 (1982), S. 97-102 
    ISSN: 1432-2242
    Keywords: Guide dogs ; Behaviour ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many dogs are found to be unsuitable for training as guide dogs for the blind. Consequently the Royal Guide Dogs for the Blind Association of Australia has embarked on a breeding program to produce a strain of labrador dogs which is suitable for guide dog training. The most common reasons for rejecting dogs are fearfulness, dog distraction, excitability, health and physical reasons and hip dysplasia. The selection program seems to have been successful in improving the success rate mainly by lowering fearfulness, but there has not been a continuing improvement. This is probably due to continual introduction of dogs from other populations into the breeding program. Males suffer from a higher rejection rate due to dog distraction and a lower rejection rate due to fearfulness and excitability than females, so that there is little sex difference in overall success rate. The heritability of success (0.44) is high enough to predict further progress from selection, again mainly against fearfulness. Variation in environment prior to 6 weeks of age, in age when dogs were placed into a private home and in age when males were castrated, had little effect on the success rate.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 62 (1982), S. 233-239 
    ISSN: 1432-2242
    Keywords: Hordeum vulgare ; Haploids ; Androgenetic responsiveness ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Anthers of 55 different spring barley (Hordeum vulgare) hybrids and four varieties were cultured in vitro. Microspores of each hybrid gave rise to calluses and subsequently plantlets, from all hybrids, except one. As criteria of microspore responsiveness, callus formation and plant regeneration frequencies were studied in detail. Large differences with regard to these criteria were found, which were traced back to the genotype of the anther donor plant. Callus formation varied between 3.3 and 73.2 per 1,000 anthers plated, whereas green plant regeneration ranged from 0 to 12.7 per 1,000 anthers cultured. Comparisons of microspore regeneration frequencies of hybrids and their parents indicated that culture responsiveness is a heritable, complex character involving at least two different and separately inherited mechanisms: 1) the ability of microspores within anthers to divide and give rise to calluses and subsequently 2) the ability of calluses for morphogenesis, to yield green or albino plants. Because it is heritable, anther culture responsiveness can be transferred to breeding material which is initially non-responsive. This genetic way of improving success in androgenetic haploid production appears to be more realistic than the search for optimum culture conditions.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Plant ecology 50 (1982), S. 23-42 
    ISSN: 1573-5052
    Keywords: Beech ; Beechwoods ; Bioclimatology ; Fagus ; Genetics ; Mediterranean region ; Vegetation structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The study area is at the southern limit of the beech area, between the rivers Rhône in France and Ebro in Spain. From an analysis of the occurrence of beechwoods in this region and the pluviometric climate, it appears that part of the beechwood is found in a dry climate, which is still mediterranean. This argument seems sufficient to justify the existence of a ‘mediterranean’ beechwood, at least on a climatic level. Beechwood when occurring in a dry climate has special characteristics: - The development of the wood differs with the climate. Young beeches need shadow in a dry climate; they can grow in full light in a moist climate. - The floristic composition is different. - The understorey of dry woods is less structured than that of moist woods. - The genetic structure as measured in the enzymatic system Px1 is polymorphic in the dry and monomorphic in the moist conditions studied. It would be interesting to verify if the characters noted in a dry mediterranean climate are also present in dry atlantic or continental beechwoods. Since the mediterranean climate is drier and more unfavorable to beech than other climates, the particular characters of ‘dry’ beechwoods will be more pronounced near the Mediterranean.
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 1-6 
    ISSN: 0192-253X
    Keywords: glycerol-3-phosphate dehydrogenase ; isozymes ; mice ; genetics ; development ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genetic variants that affect the heat stability and ionic charge of the adult isozyme of glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) map to a gene, Gdc-1, located on chromosome 15. A second isozyme of glycerol-3-phosphate dehydrogenase, structurally homologous to the product of the Gdc-1 locus and expressed predominantly in undifferentiated tissues, has previously been identified. We have now discovered an electrophoretic variant of this embryonic isozyme. This expression is determined by a codominant allele of the gene, Gdc-2, that maps to the distal end of chromosome 9 as inferred from the observed gene order Mpi-1-d-Mod-1-Gdc-2.
    Additional Material: 1 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 273-273 
    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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  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 299-308 
    ISSN: 0192-253X
    Keywords: survival ; selection ; heat-shock proteins ; Drosophila melanogaster ; temperature compensation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Two stocks of Drosophila melanogaster, one sensitive (6.5% survival) and one resistant (76.24%) to heat shock (40°C/25 min) were derived through indirect selection [1]. Genetic analysis of heat-sensitive and heat-resistant lines we had selected revealed that the survival rate is chiefly determined by cytoplasmic inheritance but also depends to some extent on the nucleus [1]. The ability of the fly to survive thermal stress was found to have an excellent correlation with the kinetics of protein synthesis in ovaries or glands subjected to heat treatment. The incorporation rate of 35S-methionine into proteins was found to be higher for strains exhibiting higher survival (R1, R1S1) than for strains with a lesser ability (S1, S1 R1) to survive heat shock. Moreover, the intensity of labeling of the proteins synthesized and especially of the hsps (heat-shock proteins) after the heat shock is higher in the R1 and R1S1 stocks than in the S1 and S1R1 stocks. This convergence between survival and the cellular level of hsps (both manipulated by selection) bears on the physiological significance of these proteins which seems to participate in the control of the survival as an additive component.
    Additional Material: 3 Ill.
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  • 11
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 371-372 
    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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  • 12
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 197-205 
    ISSN: 0192-253X
    Keywords: mouse fetal erythrocyte antigen ; erythropoiesis ; differentiation ; gene switching ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Bone marrow cells from normal adult mice were introduced by microinjection via the placenta into W/Wv genetically anemic fetuses of 11 days' gestation. After birth, erythrocytes were fractionated by fluorescence-activated cell sorting on the basis of antibody binding to a fetal-specific antigen (Ft). Lysates of Ft-positive, i.e., fetal, erythrocytes did not detectably contain hemoglobin of the donor type, as judged from electrophoresis of strain-specific hemoglobin variants. Thus, adult hematopoietic bone marrow cells did not resume fetal differentiation despite their post-transplant maturation in a fetal environment.
    Additional Material: 3 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 255-272 
    ISSN: 0192-253X
    Keywords: salivary glands ; pupation stage ; protein synthesis and transport ; prepupal development ; developmentally regulated proteins ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Pulse-labeling experiments of salivary glands from the prepupal stages of development showed selectively high rates of synthesis of a set of low molecular weight proteins (6K-12K). These proteins are stably maintained in the salivary glands during prepupal development and are subsequently transported to the pupation fluid (found between the pupal case and the prepupal cuticle) when pupation occurs. These small polypeptides are very basic with the major components having isoelectric points of 8.6-8.7 and the minor components having isoelectric points of 9.1-9.5. This study shows the continuing function of the salivary glands - specifically, the synthesis and secretion of a set of proteins with a putative role in pupation.
    Additional Material: 8 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 129-142 
    ISSN: 0192-253X
    Keywords: glycerol phosphate dehydrogenase ; turnover ; Drosophila ; gene dosage ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In vivo radiolabeling of Drosophila melanogaster sn-glycerol-3-phosphate dehydrogenase (E.C. 1.1.1.8; GPDH) has been accomplished by microinjection of 3H-leucine into anesthetized flies. Comigration of immunoprecipitated radiolabeled GPDH with purified 14C-labeled GPDH-1 in SDS polyacrylamide disc gels has established the monospecificity of our immunoprecipitation technique. Short-term uptake experiments have demonstrated that maximum radiolabel incorporation of total TCA precipitable protein and immunoprecipitable GPDH-1 occurs within 4 hours postinjection, with GPDH-1 accounting for approximately 1% of the total radiolabeled TCA precipitable protein. In order to develop the parameters for turnover studies of GPDH in Drosophila, a comparative analysis of the rates of synthesis and degradation of GPDH-1 in flies bearing two and three doses of the structural gene have been conducted by the construction of adult flies aneuploid and euploid for the cytogenetic region 25F-26B on the left arm of chromosome II. Short-term uptake studies have demonstrated that the rate of GPDH-1 synthesis in the three-dose flies is approximately 1.58 times that found in the two-dose euploid flies. This value is in close agreement with data obtained for steady-state levels of CRM by rocket immunoelectrophoresis. In contrast, longterm pulse-chase experiments have revealed that rates of GPDH-1 degradation in these aneumploid and euploid flies appear to be identical. These data suggest that the rate of GPDH-1 synthesis in Drosophila is primarily regulated by a tightly linked cis-acting element which appears to act autonomously with respect to gene copy number as well as steady-state GPDH protein levels.
    Additional Material: 5 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 165-176 
    ISSN: 0192-253X
    Keywords: X-chromosome inactivation ; digynous triploidy ; mouse ; post-implantation embryo ; late replication ; Cattanach's translocation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Using BrdU-labeling and acridine orange staining, the behavior of X-chromosome replication was studied in 28 XXX and 19 XXY digynous mouse triploids. In some of these the paternal and maternal X chromosome could by cytologically distinguished. Such embryos were obtained by mating chromosomally normal females with males carrying Cattanach's X chromosome which contains an autosomal insertion that substantially increases the length of this chromosome. In the XXX triploids there were two distinct cell lines, one with two late-replicating X chromosomes, and the other with only one late-replicating X. The XXY triploids were also composed of two cell populations, one with a single late-replicating X and the other with no late replicating X chromosome. Assuming that the late-replicating X is genetically inactive, in both XXX and XXY triploids, cells from the embryonic region tended to have only one active X chromosome, whereas those from the extra-embryonic membranes tended to have two active X chromosomes. The single active X chromosome was either paternal or maternal in origin, but two active X chromosomes were overwhelmingly maternal in origin, suggesting paternal X-inactivation in extra-embryonic tissues.
    Additional Material: 3 Ill.
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  • 16
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 207-214 
    ISSN: 0192-253X
    Keywords: germ line clones ; bithorax lethals ; dominant female sterile mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three Ultrabithorax (Ubx) alleles and three different deficiencies of the bithorax complex (BX-C) of Drosophila melanogaster have been tested for maternal effects in the germ line. The dominant female sterile technique was used. The Ubx alleles and a deletion of the abdominal region of the BX-C are homozygous viable in germ line clones and show no maternal effects. Two deletions which lack the proximal portion of the BX-C are lethal in the female germ line indicating either that these deficiencies lack genes apart from the BX-C that are necessary for fertility or that there are BX-C genes that are essential for normal maternal germ line function. The significance of the bias in the isolation of only zygotic mutations at the BX-C are discussed with respect to these results.
    Additional Material: 1 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 235-245 
    ISSN: 0192-253X
    Keywords: Drosophila ; chitin biosynthesis ; lethalcryptocephal mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Estimation of chitin deposition in the pupal and adult cuticles of adult Drosophila melanogaster during the pupal period is described. The timing of the periods of chitin deposition is compared with that deduced by previous workers using electron microscopy. The hypothesis that lethalcryptocephal mutant homozygotes are unable to evert their cephalic complexes at pupation because of excess chitin deposition is examined. The data obtained show no evidence that the mutation has any effect on chitin deposition.
    Additional Material: 4 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 19
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 283-297 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; cAMP-unresponsive mutants ; parasexual genetic analysis ; cell differentiation ; chemotaxis to folate and cAMP ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To find mutants of Dictyostelium discoideum that are unable to respond to exogenous cAMP signals (frigid mutants), amoebae of 218 independent aggregation-deficient mutants were treated in suspension with artificial pulses of cAMP and screened for the capacity to form EDTA-resistant cohesion sites. Eleven frigid mutants were identified and further characterized. Using parasexual genetic techniques, these strains were assigned to five complementation groups (fgdA-E) and the fgd loci were mapped in three linkage groups: fgdA and D in group II, fgdC in group III, and fgdB and E in group VII. Biochemical and physiological experiments with these strains indicated that fgd mutants are of two general types. When starved, strains in groups fgdB, D, and E failed to produce detectable levels of membrane-associated cAMP phosphodiesterase, surface cAMP receptors, or extracellular phosphodiesterase inhibitor, and the cells continued to respond chemotactically to folate. Thus, these strains are probably arrested in the vegetative phase or very early in development. In contrast, strains in groups fgdA and C produced low levels of cAMP receptors and secreted phosphodiesterase inhibitor. Moreover, after starvation, some of these mutants elicited a weak chemotactic response to cAMP. Therefore, unlike the former group of mutants, these strains appear to initiate development when starved, but the process is blocked at an early stage.
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  • 20
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 365-365 
    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 3 (1982) 
    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
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 7-23 
    ISSN: 0192-253X
    Keywords: gene expression ; superoxide dismutase ; Zea mays ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Immunoassays for the cytosolic and mitochondrial superoxide dismutases (SOD) of maize were developed and used to study the expression of these proteins in the maize seedling. The genetically distinct proteins, SOD-3 and SOD-4, are preferentially expressed in the scutellum, comprising approximately 1% of the total water-soluble protein of that tissue. SOD-2, SOD-3, and SOD-4 are synthesized in the scutellum during early sporophytic development, probably on cytosolic ribosomes. Two-dimensional gel electrophoresis of crude scutellar extracts indicates that significant changes occur in the protein composition of the maize scutellum following seed imbibition. Using the immunoassays, a maize line exhibiting a significant reduction in cyanide-sensitive SOD protein was identified.
    Additional Material: 8 Ill.
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  • 23
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 24
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 177-177 
    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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  • 25
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 179-196 
    ISSN: 0192-253X
    Keywords: alcohol dehydrogenase ; regulatory ; mutant ; mutable alleles ; organ-specific ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three new mutant alleles of maize alcohol dehydrogenase-1 (Adh 1) were recovered following allyl alcohol selection of pollen. Each is altered in quantitative, organ-specific, regulatory properties. All mutant sites act in cis to the structural gene component. One mutant arose spontaneously, one followed indirectly from irradiation with high Z accelerated particles, and one was induced by an autonomous mutator system. Each mutant is assessed in three organs by utilizing ADH allozyme ratios that were quantified at the level of ADH enzyme activity and either [3H]-Leu incorporation into newly synthesized ADH 1 subunits or direct protein determinations. One mutation simultaneously raises Adh 1 expression in one organ and lowers it in another, another affects expression in one organ only, and another is extremely underexpressed in all organs but is unstable. This unstable allele has generated derivative mutant alleles that have less or zero ADH expression. We do not yet know whether or not coding sequences are involved in these mutants. We conclude that information for organ specificity and quantitative behavior resides near or within Adh 1 coding sequences.
    Additional Material: 6 Ill.
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  • 26
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982) 
    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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  • 27
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 69-89 
    ISSN: 0192-253X
    Keywords: female sterility mutations ; fusome ; incomplete cytokinesis ; interconnected sibling cells ; ongenesis ; ovarian tumor genes ; polytene chromnsomes ; pseudonurse cells ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A comparative cytological study was made of oogenesis in flies carrying various mutant alleles of the female sterile gene otu. It resides at 22.7 on the genetic map and within subdivision 7F of the cytological map of the X-chromosome. Each of the five ethyl methane sulfonate-induced mutations observed falls into one of three classes. In class 1, most mutant ovarioles lack germ cells; in class 2, most mutant ovarioles contain tumorous chambers; and in class 3 mutants, chambers occur that possess defective oocytes. The otu2 allele belongs to class 1; otu1 to class 2; and otu3, otu4, and otu5 to class 3. The mutations have no effects upon female viability or upon the viability and fertility of hemizygous males. Heterozygous females are fertile and have cytologically normal ovaries. In otu5 homozygotes, all ovarioles contain egg chambers, but oogenesis is prematurely terminated to produce a pseudo-stage 12 oocyte. Ovarioles from otu3 and from otu4 homozygotes contain both ovarian tumors and oocytes. Pseudonurse cells (PNC), which are cystocytes that have stopped dividing and have entered the nurse cell mode of development, are also abundant. PNCs contain polytene chromosomes. Since the homologs are paired, each nucleus has the haploid number of chromosomes. In chambers lacking an oocyte, the number of PNCs is less than the normal number of nurse cells. In chambers containing an oocyte, the number of accompanying nurse cells may be 15, or above or below normal. In vitellogenic chambers, the chromosomes in the nurse cells connected directly to the oocyte are more expanded than those in more distant nurse cells. The KA14 deficiency lacks the plus allele of otu. KA14 heterozygotes are fertile and have cytologically normal ovaries. When females carry KA14 and otu1, otu3, otu4, or otu5, 80% of their ovarioles are agametic. When females carry otu2 and one of the other mutant alleles, the ovarioles proceed further in development. So otu2 produces a product that has a beneficial effect on the test allele. When two different otu alleles are combined in a single fly, the phenotype of the hybrid ovary usually most resembles that of the ovary homozygous for the “stronger” allele (the otu mutant that allows oogenesis to proceed farthest). The results indicate that the product of the otu+ locus functions at least three different times during oogenesis; first to permit oogonia to proliferate, second to control the division and differentiation of germarial cystocytes, and third to facilitate the normal growth of the ooplasm. The gene product appears to be required in higher concentrations at each developmental period. The lesions produced by the mutations are thought to interfere with the stability or functioning of the gene product, and the ovarian phenotype produced by a given genotype depends upon the concentration of functional gene product available to the germ cells.
    Additional Material: 8 Ill.
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  • 28
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 103-113 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; Polycomb ; homoeotic mutation ; determination ; maternal effect ; embryogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: When heterozygous, dominant mutant alleles of the Polycomb locus are associated with a variety of adult homoeotic effects. Zygotes homozygous for these alleles die as late embryos showing homoeotic transformation of head, thoracic, and abdominal segments. This study shows that embryos homozygous for Pc3 are more extreme than those homozygous for Pc1 or Pc2. Moreover, Pc1/Pc3 heterozygotes are more extensively transformed if their mothers were Pc3/ + than if they were Pc1/ +; this effect does not depend on zygotic genetic background and must be maternal in nature. Embryos homozygous for Pc3 are less extreme if they arise from Pc3/ + / + than from Pc3/ + mothers. These results strongly suggest that the Polycomb locus acts maternally as well as zygotically to affect early determinative decisions.
    Additional Material: 5 Ill.
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  • 29
    ISSN: 0192-253X
    Keywords: B cell development ; immunoglobulin M ; B cell tumor ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Tumors of B lymphocyte origin have been used as models for normal B cells “frozen” at particular stages of their development. Surface properties, amount, and intracellular location of immunoglobulin and the synthesis of J chain have all been used as indicators of developmental stages. Each requires special techniques or yields data that are difficult to compare from one experiment to the next. For these reasons, we have developed a metric for B cell development that is simple to perform and allows quick quantitative comparisons of cell lines.It has recently been established that the membrane (μm) and secreted (μs) forms of the IgM heavy chain differ at their extreme carboxy termini. The two proteins differ slightly in size and are easily distinguished when they are compared without their carbohydrate on sodium dodecyl sulfate (SDS) polyacrylamide gels. We have examined four mouse tumors derived from the B lymphocyte lineage whose phenotypes resemble late pre-B cells (internal μ only; uninduced 70Z/3), small B lymphocytes (high levels of surface IgM; LPS-induced 70Z/3, WEHI 231), lymphoblasts (both membrane and secreted IgM; WEHI 279.1), and plasma cells (copious IgM secretion; MOPC 104E). Despite the fact the 70Z/3 and WEHI 231 secrete no detectable IgM, all of the tumors synthesize at least intracellular forms of both μm and μs. The proportion of μm is stable and is characteristic of each tumor. The 70Z/3 cells and WEHI 231 cells synthesize about 75% of their total μ as μm; WEHI 279.1 cells synthesize about 30% and MOPC 104E cells about 5% of their total μ as μm. The population of LPS-stimulated B lymphocytes shows a similar progression during its differentiation. The proportion of μm correlates with other developmentally regulated parameters (Fc receptor, Ia and plasma cell antigen levels, and J chain) and can be used as a simple metric for comparison with developing B lymphocytes and determination of the developmental stage of a B cell tumor.
    Additional Material: 4 Ill.
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  • 30
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 143-154 
    ISSN: 0192-253X
    Keywords: imaginal neurogenesis ; visual development ; genetic mosaics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The neural phenotype of an imaginal disc degenerate mutant l(1)d deg-3 was studied in histological sections. The mutant larvae showed severe abnormalities in the imaginal neural development. Gynandromorphs, which are composed of genetically mutant and nonmutant cells, were generated and analyzed as late larvae. The results of mosaic analysis were consistent with l(1)d deg-3 gene acting autonomously in the imaginal disc and imaginal neural cells. The optic lobe development patterns observed in the larval mosaics provided evidence for an eye disc-optic lobe interaction during the late third instar larval stage.
    Additional Material: 6 Ill.
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  • 31
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 329-345 
    ISSN: 0192-253X
    Keywords: Drosophila embryo ; mutation ; myogenesis ; fibrillogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The I(1)fdg mutation demonstrates two separate phases of lethality, depending on developmental conditions. At 32-33°C, an embryonic lethality is expressed whereas at lower temperatures a larval-pupal lethality is observed. This larval-pupal lethality characteristically produces noncondensed, curved puparia, and since the contraction of the pupa depends on strong muscular contraction, this phase of lethality implicates some involvement of abnormal musculature. The embryonic expression of I(1)fdg at 32-33°C is the subject of this study. In these embryos, which are alive but immobile (incapable of hatching), the fibrillar organization and fiber morphology of the somatic musculature varies from being apparently normal to being grossly abnormal. While the abnormalities appear as unusual distributions of fiber organelles, abnormal convolutions of the muscle fibers, and disorganizations of fibrillar components, it seems most probable that the underlying defect ultimately responsible resides in some system essential for Z body alignment and sarcomere formation. Accompanying the embryonic lethality, certain abnormalities in midgut development are observed which at present do not appear to be related to the defects observed in the somatic muscle.
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  • 32
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 347-363 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; muscle defect ; genetic mosaics ; allelic variability ; intragenic complementation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The recessive X-linked mutation erect wing (ewg), in Drosophila melanogaster, was characterized as a flightless behavioral mutant which specifically lacked the dorsal longitudinal flight muscles [1]. This mutation was mapped distal to the X chromosomal locus yellow, and further to the cytological segment 1 A 1 to 1 B2-3 [2]. Several lethal complementation groups have been mapped to this interval [3]. Our complementation tests show that ewg is allelic to one lethal complementation group in the region 1 A 1 to 1 B2-3. A further analysis of ewg and several lethal alleles isolated at this locus was undertaken in the present investigation. Most of the lethal alleles at this locus lead to a late embryonic or early larval lethal phase, indicating that the ewg+ gene product is necessary for the development of more than just the dorsal longitudinal flight muscles. Intragenic complementation was observed for some of the ewg lethal alleles. Genetic mosaics with ewg lethal alleles showed that mutant cell clones in cuticular structures are viable. Mosaic analysis is consistent with a mesodermal defect associated with the locus.
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  • 33
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 41-51 
    ISSN: 0192-253X
    Keywords: Artemia ; histone synthesis ; histone genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The synthesis of histones and presence of histone mRNA sequences in embryos and larvae of the brine shrimp, Artemia, were investigated. Radiolabeling of proteins synthesized in vivo followed by electrophoretic and fluorographic analysis confirmed the prediction that histone synthesis is coordinated with the wave of DNA replication in newly hatched larvae. No histone synthesis occurs during development of encysted embryos. Hybridization of cloned Artemia histone gene DNA to total cell RNA indicated that dormant encysted embryos do not contain “masked” messenger RNA.
    Additional Material: 4 Ill.
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  • 34
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 91-102 
    ISSN: 0192-253X
    Keywords: hyperthermia ; heat shock ; phenocopy ; teratogenesis ; morphogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have for some years been making use of phenocopies in Drosophila, as induced by heat shock, as tools for studies of the molecular events in morphogenesis [18, 21, 22]. In this paper, we have brought together some accumulated information on the conditions for phenocopy production, on a temporal sequence of sensitivity to induction, and on the nature of many of the morphogenetic abnormalities that can be induced. In general, the induction of phenocopies by heat shock requires conditions drastic enough to turn off transcriptional activities but not extreme enough to prevent recovery. This situation is most easily achieved in pupal stages where heat resistance is high, but even in this range, resistance varies with the stage of development.The phenocopies described resemble, for the most part, mutants that affect structures derived from epithelial differentiation or muscle development.
    Additional Material: 5 Ill.
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  • 35
    ISSN: 0192-253X
    Keywords: tumorous and nontumorous genotypes ; DNA amplification ; repetitive DNA ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The possible relevance of changes in amounts of highly repetitive DNA sequences for plant differentiation and dedifferentiation processes has been suggested in several cases. Data are lacking however on (1) the genetic control of these phenomena and (2) cause-effect relationships between DNA amplification and specific ontogenetic patterns.The present study was carried out on a Nicotiana genetic system consisting of the tumorous amphidiploid N glauca X N langsdorffii, a nontumorous mutant of it, their F1, and a backcross to the tumorous parent. Backcross segregation ratios were shown to be compatible with a “single gene” hypothesis, the F1 plant being nontumorous but showing a low percentage of tumors induced by wounds, 6-azauracil or X-rays.In vitro studies of excised pith tissue grown on Linsmaier and Skoog medium for different periods of time showed the presence, confirmed by cytological analyses, of amplification of highly repetitive sequences only in the nontumorous stock, as judged by reassociation experiments in the first 24-96 hours of culture. CsCl analytical ultracentrifugation of those sequences showed the appearance in the same stock of a heavy DNA satellite (density = 1.721 gm/ml), whose presence was also confirmed by derivative melting curves.Amplification seemed to be essential for the initiation of cell division, which was completely inhibited in the nontumorous genotype and partially influenced in the F1 by incorporation during the critical period (24-96 hours of the primary explant) of 5-bromo-2′-deoxy-uridine.The results are discussed in terms of an hypothesis of an integrated gene-controlled, hormone-mediated regulatory system of cell proliferation involving changes in target repetitive DNA sequences.
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  • 36
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 115-128 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; polygenic variation ; pattern formation ; wing veins ; campaniform sensillae ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This study was designed to measure the degree of correlation between vein formation and the specification of campaniform sensillae positions in the wing of Drosophila melanogaster. The campaniform sensillae are sensory organs placed at various locations on the wing. Those on the third longitudinal vein (L3) were the focus of this analysis. The system of polygenic modifiers of vein length is comparatively simple, as shown in whole chromosome assays of selected lines. This variability provides a sensitive method of altering vein-forming ability and of assessing correlated changes in other parts of the vein pattern. In selection lines of veinlet, sensillae were displaced toward the base of the wing as vein length decreased by distal loss of vein material. Changes in the amount of vein were, however, not directly proportional to changes in sensillae positions. The more distal sensillae were shifted the largest amount. In the mutant tilt, in which reduced L3 vein-forming competence results in subterminal gaps, distal campaniform sensillae were almost completely eliminated. The remaining sensillae were shifted toward the base of the wing where vein formation is normal. The placement of sensillae therefore appears to be sensitive to the same underlying determinants involved in vein-forming competence.
    Additional Material: 6 Ill.
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  • 37
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 155-163 
    ISSN: 0192-253X
    Keywords: shiverer mouse ; myelin ; myelin basic protein ; myelination ; proteolipid protein ; sciatic nerve ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The central nervous system of the shiverer mouse is known to be severely deficient in myelin. Animals heterozygous for this autosomal-recessive mutation were crossed, and the myelin proteins were examined in the brains and spinal cords of shiverers and unaffected littermates among the offspring. In the brains and spinal cords of nine of the 14 unaffected littermates examined, the quantities of the myelin basic and proteolipid proteins were lower than normal. Furthermore, in the brains of heterozygotes 33 to ∼ 150 days old, the myelin basic and proteolipid proteins were reduced in amount, compared to wild-type controls; the myelin basic protein was also present in subnormal amounts in the spinal cords from heterozygous animals at the ages of 17 to 150 days. More severe reductions in the quantities of the myelin proteins were observed in central nervous system tissue from homozygous shiverer mice, and the quantity of the myelin proteolipid protein in the central nervous system of the shiverer mouse, expressed as a ratio to the control value at each age, underwent a developmental decline. In heterozygotes, as well as shiverers, the peripheral nerves were also deficient in the P1 and Pr proteins, which are the same as the basic proteins in rodent central nervous system myelin. The findings regarding heterozygotes suggest that the defective primary gene product in the shiverer mouse could be the myelin basic protein itself or a protein required for a rate-limiting step in the processing of the myelin basic protein.
    Additional Material: 5 Ill.
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  • 38
    ISSN: 0192-253X
    Keywords: urate oxidase ; 20-hydroxyecdysone ; Drosophila melanogaster ; Malpighian tubules ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The tissue-specific enzyme urate oxidase is confined exclusively to the Malpighian tubules of Drosophila melanogaster and expressed only in the third-instar larva and the adult. Shortly before pupariation urate oxidase activity declines precipitously and is not detectable 24 hours later. That 20-hydroxyecdysone is the factor that triggers the disappearance of urate oxidase activity in late third-instar larvae is demonstrated using the temperature sensitive mutant ecd1 which at the nonpermissive temperature of 29°C fails to accumulate a sufficient concentration of 20-hydroxyecdysone necessary for puparium formation and thus remains a third-instar larva for 1 to 2 weeks before death. Both the life cycle and the temporal profile of urate oxidase activity in ecd1 larvae at 19°C is identical to that of the wild type. However, at 29°C ecd1 third-instar larvae retain high urate oxidase activity. A precipitous decline in urate oxidase activity is observed when ecd1 larvae at 29°C are fed 20-hydroxyecdysone. These data implicate 20-hydroxyecdysone in the process that controls the rapid decline of urate oxidase activity at the time of puparium formation. In whole homogenates of Malpighian tubules, the urate oxidase polypeptide was identified in SDS-polyacrylamide gels by its Rf with respect to homogeneously pure Drosophila urate oxidase and also by immunoprecipitation with rabbit anti-Drosophila urate oxidase IgG. Throughout development the amount of the urate oxidase polypeptide is correlated with the magnitude of urate oxidase activity.
    Additional Material: 8 Ill.
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  • 39
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 247-253 
    ISSN: 0192-253X
    Keywords: H-Y antigen ; sex determination ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Karyotypically XY individuals of the C57BL/6J-YPOS mouse stock develop as females or hermaphrodites, but never as normal males. The aberrant sexual development results from the interaction of the C57BL/6J genetic background with the M. poschiavinus-derived Y chromosome. XY females from this stock were assayed for H-Y antigen. By the criteria of skin-grafting, the cell-mediated lympholysis test, and the popliteal lymph node assay, these XY females are antigenically indistinguishable from normal C57BL/6 males. Implications for the hypothesis that H-Y antigen induces formation of the mammalian testis are discussed.
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  • 40
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 275-282 
    ISSN: 0192-253X
    Keywords: Drosophila ; sex chromosomes ; gene dosage ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In Drosophila, the ratio of the number of X chromosomes to sets of other chromosomes initiates a series of events which result in sexual differentiation. In addition, this ratio establishes dosage compensation, a mechanism which equalizes the products of X-linked genes in males and females. The present review discusses possible genetic entities responsible for the interpretation of chromosomal sex and subsequent sex-mediated regulation during development.
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  • 41
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 309-327 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; DNA polymerase ; developmental enzyme profile ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An assay procedure was developed that allowed the first reproducible measurement of DNA polymerase activity in all developmental stages of Drosophila melanogaster. Evidence is presented that the same enzymatic species is present in extracts of embryos, pupae, and adults of both sexes and that this activity has many properties similar to vertebrate α-polymerases. Polymerase activity per individual is low in embryos and rises steadily through larval instars, reaches a peak in early pupae, declines through the late pupal period, and remains low in newly eclosed adults of both sexes. A dramatic increase is observed in adult females as mature oocytes are formed. This pattern of enzyme activity is completely coincident with changes in DNA levels during development, and suggests that the Drosophila enzyme, like vertebrate α-polymerases, functions in cellular DNA replication. Two mutagen-sensitive mutants, deficient in both replication on undamaged templates and postreplication repair, were found to have normal levels of this α-polymerase activity. Our results suggest that a single enzymatic species of α-polymerase holoenzyme exists in Drosophila and is common to all developmental stages of this organism.
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