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  • Articles  (17)
  • Drosophila melanogaster  (17)
  • Springer  (17)
  • American Chemical Society (ACS)
  • International Union of Crystallography
  • International Union of Crystallography (IUCr)
  • 2005-2009
  • 1990-1994
  • 1980-1984  (17)
  • 1980  (17)
Collection
  • Articles  (17)
Keywords
Publisher
  • Springer  (17)
  • American Chemical Society (ACS)
  • International Union of Crystallography
  • International Union of Crystallography (IUCr)
Years
  • 2005-2009
  • 1990-1994
  • 1980-1984  (17)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 127-132 
    ISSN: 1432-041X
    Keywords: Pole cell isolation ; Maternal effect mutants ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A procedure for pole cell isolation has been developed that takes advantage of theDrosophila melanogaster maternal effect mutantmat(3) 1. Embryos derived from homozygousmat(3)1 mothers form exclusively pole cells. By outcrossing we could substantially increase the expressivity of the original mutant stock. We further introduced theTM8 balancer chromosome, which carries the dominant temperature sensitive mutationDTS-4. This allows the accumulation of large homozygousmat(3) 1 fly populations by eliminating the heterozygous flies at the restrictive temperature. Early embryos were mechanically fragmented and the cells were isolated by means of metrizamide step gradients. The isolated cells were demonstrated to exhibit the various ultrastructural and histochemical characteristics of pole cells. The isolated cells were transplanted into genetically marked host embryos. The germ line mosaics that were obtained indicate that the isolated cells represent functional pole cells. Proteins synthesized by the isolated pole cells during short term in vitro labelling with35S-methionine were compared to the proteins synthesized by blastoderm cells fromOregon-R embryos. At least one protein could be demonstrated in the pole cell samples that is not synthesized byOregon-R blastoderm cells. The method allows a fast and gentle isolation of highly enriched pole cell populations which are a prerequisite for the biochemical analysis of germ cell determination and differentiation.
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  • 2
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; choice of oviposition site ; strain difference ; site discrimination ; egg insertion ; selection ; wild type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Females ofDrosophila melanogaster were given a choice of oviposition site either on the surface of the medium or on the surface of paper positioned vertically on the medium. A significant difference was seen in the proportion of eggs deposited on the paper among wild strains of different geographic origins. Bidirectional selection for oviposition on these two sites was effective. These selected lines were examined under various conditions to determine the factors involved in this site selection for oviposition. The lines that chose medium laid eggs only on substrates into which egges could be inserted. The lines preferring paper showed no strict requirement for burying their eggs. Tarsal sensillae were involved in site discrimination.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 10 (1980), S. 163-170 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; mating success ; male fertility ; male age ; female choice experiments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Female choice experiments were used to investigate the effect of relative male age on mating success inD. melanogaster. Experiments were conducted with a Canton-S (CS) strain, in which two virgin males of different ages (2, 4, or 8 days old) were offered to virgin females. Older males were found to be more successful under competitive conditions. In another group of experiments, vermilion (v) males of different ages competed with CS males of different ages. The competitive success ofv males was found to increase with their relative age. Male fertility at 2, 4, and 8 days of age was documented for both male genotypes mated with CS females. CS males fathered more offspring per copulation thanv males, and the fertility of all males was found to increase with age. Discussion focuses on the changes in male mating success and fertility with age and genotype.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 65-76 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; cuticle ; chitin ; β-alanine ; N-acetyldopamine ; tanning ; melanization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In Drosophila melanogaster, the chitinous microfibrils arising from the tips of the epidermal villi in adult cuticles remain irregular and loose in the mutant ebony (which fails in cuticular incorporation of β-alanine) but closely knit and regular in normal flies. Addition of β-alanine to cuticles from which nonchitinous materials have been removed with alkali converts the loose arrangement of the microfibrils to a compact and sharply delineated arrangement. β-alanine also accelerates tyrosinase-catalyzed oxidation of N-acetyldopamine by reacting with the oxidized product of the reaction to produce an orange-red complex. Similarly, β-alanine accelerates oxidation of N-acetyldopamine when these two substances are added to fluids from the hemocoel, to lead to tanning instead of normal blackening. These findings may help explain why β-alanine induces tanning while inhibiting melanization in insects.
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  • 5
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; 6-phosphogluconate dehydrogenase ; isozyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 6-Phosphogluconate dehyrogenase is evident at all developmental stages of Drosophila melanogaster. The activity level is highest in early third instar larvae and declines to a lower, but relatively constant, level at all later stages of development. The enzyme is localized in the cytosolic portion of the cell. The A-isozymic form of 6-phosphogluconate dehydrogenase was purified to homogeneity and has a molecular weight of 105,000. The enzyme is a dimer consisting of subunits with molecular weights of 55,000 and 53,000. For the oxidative decarboxylation of 6-phosphogluconate the Km for substrate is 81 µm while that for NADP+ is 22.3 µm. The optimum pH for activity is 7.8 while the optimum temperature is 37 C.
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  • 6
    ISSN: 1573-4927
    Keywords: Tryptophan ; kynurenine ; white ; Drosophila melanogaster ; amino acid transport ; Malpighian tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Dissected Malpighian tubules from wild type and the eye color mutant white of Drosophila were compared with respect to their abilities to transport tryptophan and kynurenine into tubule cells. It was determined that mutation at white greatly impairs the ability of Malpighian tubule cells to take up tryptophan. Functional studies on the extracellular spaces and ultrastructural observations indicated no differences in these respects between wild type and white tubules. It is consistent with several observations that much of the tryptophan associated with white exists in the intercellular spaces. Furthermore, the uptake of tryptophan by the w + system of wild type tubules is inhibited by the analogue 5-methyl-tryptophan. However, the incorporation of radioactive tryptophan into protein in tubule cells from wild type and white occurs at the same rates and is not affected by 5-methyl-tryptophan. Therefore, it is apparent that Malpighian tubules have a transport system that enables entry of tryptophan into a cellular pool and that this cellular pool is initially independent of the tryptophan pool used for protein synthesis. The mutant white lacks this transport system. From these studies and others it appears that compartmentalization of cellular pools may be brought about via the utilization of specific membrane transport systems.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 303-309 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; allozymes ; GPT ; genetic mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have used electrophoretic variants of glutamate-pyruvate transaminase (GPT, E.C. 2.6.1.2) in Drosophila melanogaster to genetically map the structural gene to position 42.6 on the X chromosome. By pseudodominance tests over several deficiencies we have localized it cytogenetically to the interval 11Fl-2 to 12Al-2. The sedimentation constant (s 20,w) of the native enzyme was determined in sucrose density gradients to be 5.9 and the native molecular weight approximately 87,000. The similarity in physical properties to mammalian enzymes suggests that the enzyme may also be dimeric in D. melanogaster.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 699-715 
    ISSN: 1573-4927
    Keywords: modifying genes ; G6PD activity ; 6PGD activity ; Drosophila melanogaster ; enzyme polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Different homozygous lines of similar genotype with respect to G6pd and 6Pgd were shown to have different enzyme activities for G6PD and 6PGD. Crosses between high and low lines suggested that there were modifying genes present on the autosomes, while others were probably located on the X chromosome. Allelic variation within each electrophoretic class of G6pd and 6Pgd might, however, also have contributed to this variation. An experiment on adaptation to sodium octanoate demonstrated that in adapted flies selection for lower enzyme activity had occurred, which provided further evidence for the existence of genetic differences in activity. Furthermore, a strong positive correlation between the activities of G6PD and 6PGD was found for each genotype. Since no correlation was found between MDH and the two enzymes G6PD and 6PGD, it could be concluded that this correlation was probably rather specific for G6PD and 6PGD. Interaction between genotypes with respect to activity was also found. It was shown that the variation at 6Pgd influenced the activity of G6PD within a genotype. The data are discussed in relation to fitness differences presented in foregoing articles.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 905-913 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; allozymes ; α-glycerophosphate dehydrogenase ; frequency-dependent selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Polymorphism at the α-Gpdh locus was studied in Drosophila melanogaster. Using two different lines, one marked by the F allele (FF line) another by the S allele (SS line), four populations were initiated, two in which the initial frequency of F was 0.1 and two in which it was 0.9. They have been observed for 34 generations. From the fifth generation on, the equilibrium frequency in the four cages was about 0.60. Viability has been measured during the evolution of the populations while F frequencies changed and recombinations between the FF and SS lines occurred. It has also been evaluated in synthetic populations built with different frequencies: (1) from the original FF and SS lines and (2) from FF and SS lines extracted after 34 generations of joint evolution. In all three cases, the FF viability depended on the frequency of the F allele. The similarity of the three linear regressions implies that the α-Gpdh locus or other closely linked loci is the target of the selection in the populations analyzed here.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 10 (1980), S. 183-190 
    ISSN: 1573-3297
    Keywords: ethanol ; Drosophila melanogaster ; larvae ; strain difference ; habitat selection ; isofemale strains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract There is a latitudinal cline in attraction to ethanol of newly hatchedD. melanogaster larvae; attraction decreases as one moves from the temperate regions to the Australian tropics. Tropical populations manifest high levels of heterogeneity compared with temperate regions, making tropical populations less dependent on ethanol. Since ethanol is a resource forD. melanogaster, an approach to the genetics of resource utilization in natural populations via behavior genetics of larval ethanol responses is feasible, using isofemale strains as experimental material.
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