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  • Drosophila melanogaster  (138)
  • Springer  (138)
  • American Geophysical Union
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wiley
  • 2005-2009
  • 1980-1984  (71)
  • 1975-1979  (67)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1396-1397 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; ovicidal activity ; dehydromatricaria ester ; toxicity, enhancement by UV ; polyacetylenic compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Freshly laid eggs ofDrosophila melanogaster were treated with the polyacetylenic compoundcis-dehydromatricaria ester. The toxicity of the chemical was enhanced by treatments with long-wavelength ultraviolet light, and the maximum effect was observed when the UV irradiation was performed 4–5 h after the initial contact of the eggs with the chemical.
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  • 2
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    Development genes and evolution 193 (1984), S. 133-138 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Compartment boundary ; Operculum seam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Histochemical staining of the hypoderm ofDrosophila larvae for aldehyde-oxidase activity allowed detection of a row of cells destined to form the operculum seam, along which the pupal case opens when the adult ecloses. Analysis ofmal clones in hypoderms of gynandromorph larvae showed that the prospective operculum seam coincides, in part, with a line of clonal restriction that divides the thorax into dorsal and ventral halves. We propose that this line represents the embryonic dorsal/ventral compartment boundary
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  • 3
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    Springer
    Development genes and evolution 193 (1984), S. 226-233 
    ISSN: 1432-041X
    Keywords: Wing development ; Sensory neurons ; Differentiation ; Axonal outgrowth ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary TheDrosophila wing is a simple structure bearing many sensory neurons which form an elementary pattern of nerves within the veins, and provides a simple system for studying the formation of nerve pathways. A light-and electron-microscope study of the developing pupal wing was undertaken to establish the time at which the different classes of sensillum differentiate and to determine the arrangement of tissues within the wing during sensory axon out-growth in order to assess possible candidates for directing axon outgrowth. Major findings were 1. Wing development passes through three main stages: at 6–12 h after puparium formation the wing is flantened and secreting pupal cuticle; at 15–18 h the wing is dramatically inflated but is still a simple epithelium secreting pupal cuticle; at 21–24 h the wing collapses and begins to differentiate adult structures. 2. There are no persisting larval nerves which might act as pioneers or pathfinders for the later developing adult neurons. 3. Axon bundles are first observed during the 15–18 h stage prior to the pupal moult when the wing is still secreting pupal cuticle. 4. At this stage the wing is an inflated sac, without any veins or orderly arrangements of tracheae which might act as guides for axon outgrowth. Vein formation takes placeafter formation of the axon pathways. 5. The bristle axons grow along the anterior wing margin in close contact with the basal lamina of the epithelial cells, often within a gap between the processes of the epithelial cells, which could mechanically channel their out-growth. 6. The campaniform sensillum axons appear to navigate along the inner surface of the wing epithelium rather like the pioneer axons found in embryonic appendages of other insects. 7. Differentiation of sensory neurons takes place long before differentiation of the other cells associated with sensilla; most axons are present by 18 h when the wing is still secreting pupal cuticle but morphological differentiation of the bristle shaft and socket cells is not observed until about 42 h when the wing is secreting the cuticulin layer of the adult cuticle.
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  • 4
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    Springer
    Development genes and evolution 193 (1984), S. 242-245 
    ISSN: 1432-041X
    Keywords: Chaetae ; Sensillae ; Differentiation ; Genetic regulation ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutants in two loci,hairy (h +) andextramacrochaetae (emc +), produce phenotypes corresponding to an excess of function of theachaete-scute complex (AS-C), that is, they cause the appearance of extra chaetae. These mutants, although recessive in normal flies, become dominant in the presence of extra doses of AS-C. Here we study the interactions between these three genes, in an attempt to elucidate their relationships. The results show that the insufficiency produced byh oremc mutants can be titrated by altering the number of copies of AS-C. Moreover, excess of function of AS-C produced by derepression mutants within the complex (Hairy-wing) can also be titrated by altering the number of wild type copies of+ oremc +. These specific interactions indicate that bothh + andemc + code for “repressors” of AS-C that interact with theachaete andscute region of the complex respectively.
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  • 5
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    Development genes and evolution 193 (1984), S. 246-251 
    ISSN: 1432-041X
    Keywords: Chaetae ; Differentiation ; Genetic regulation ; Pattern formation ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have already shown that theachaetae-scute complex (AS-C) ofDrosophila is regulated by two genes,hairy andextramacrochaetae. Using mutants in these genes, we have analysed how different levels of expression of AS-C affect the pattern of chaetae. The results indicate that the spatial distribution of chaetae results from cell interactions, probably by a mechanism of lateral inhibition. The results are discussed in view of the different theories of pattern formation.
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  • 6
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    Biochemical genetics 22 (1984), S. 551-566 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; larval serum protein polymorphisms ; genetic heterogeneity ; northern populations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract LSP-1βS is present in Michigan and Massachusetts Drosophila melanogaster natural populations. Its frequency, 10%, is significantly higher in an East Jordan, Mich. (latitude, 45.10° N), population than in East Lansing, Mich. (latitude 42.44° N), or Hadley, Mass. (latitude, 42.21° N), populations, where it averages 3% at each location. The average frequency of LSP-2S is more comparable, 6, 5, and 7% at East Jordan, East Lansing, and Hadley, respectively. LSP-1γF variants are also present. A total of 342 single third-instar larvae was scored for LSP-1 autosomal variants, and 323 for LSP-2 variants. Each larva represented a newly established isofemale line from collections at East Jordan in 1981 and 1983, East Lansing in 1982, and Hadley in 1981, 1982, and 1983. Within localities, frequencies of hemolymph protein variants did not differ significantly between years. Proteins 9, 10, 11, and 15 correspond to the LSP-1γ, β, and α triplet and LSP-2 polypeptide in D. melanogaster. Our results together with those of Singh and Coulthart [(1982). Genetics 102:437] indicate that D. melanogaster populations in north temperate climates maintain considerable genetic heterogeneity for the larval hemolymph proteins.
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  • 7
    ISSN: 1573-4927
    Keywords: larval serum protein ; gene dosage ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larval serum protein-1 (LSP-1) and LSP-2 are the major proteins of Drosophila larval serum. The amount of LSP-1 synthesized is strictly proportional to the number of LSP-1 genes present within the range 1–10. The normal number in female flies is 6. Flies with extreme amounts of LSP-1 were, by our criteria, as fit as the wild type. The ratio of LSP-2:LSP-1 was analyzed in 169 different stocks and was constant in 164 of these. The significantly different ratios in five stocks were all due to the lack of one of the LSP-1 gene products.
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  • 8
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    Biochemical genetics 22 (1984), S. 453-465 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; ribosomal DNA ; compensation ; selective amplification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Compensation is a mechanism by which the X-chromosome nucleolus organizer region of Drosophila melanogaster can increase its ribosomal DNA content up to twofold. It occurs in somatic cells under specific genetic conditions and is mediated by a defined genetic site, the compensatory response locus. The In and various type I ribosomal DNA repeat units were separated by restriction endonuclease digestion. Comparison of the percentages of these repeat unit types between compensating and noncompensating genotypes showed the same distribution. Therefore no selective amplification of these repeat unit types occurs during ribosomal DNA compensation. These results demonstrate that two processes of rDNA amplification in somatic cells, compensation and independent rDNA polytenization, are exclusive events.
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  • 9
    ISSN: 1573-3297
    Keywords: sympatric populations ; Drosophila melanogaster ; Drosophila simulans ; olfaction ; alcohols ; methanol ; ethanol ; propanol ; iso-propanol ; butanol ; hexanol ; octanol ; “threshold response model.”
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Alcohol preference by adults (1–2 days old) of sympatric populations ofDrosophila melanogaster andD. simulans were studied in a T-shaped glass maze. Concentrations for ethanol, methanol, propanol, and hexanol alcohols (group I) were 10, 25, 35, and 50%; for iso-propanol, butanol, and octanol alcohols (group II), they were 1.5, 2.5, 3.5, and 10%.D. simulans preferred the four alcohols in group I, more thanD. melanogaster. While moreD. melanogaster thanD. simulans preferred iso-propanol, moreD. simulans thanD. melanogaster preferred butanol. The two species had a similar preference for octanol. Regardless of the position of alcohol in the maze,D. melanogaster preferred to turn right in the presence of all alcohols, whileD. simulans preferred to turn right in the presence of group I alcohols only. At 10% concentration, males of both species preferred to turn right and females preferred to turn left. More females than males ofD. simulans preferred group II alcohols. There was no significant difference among concentrations for all alcohols in group I forD. melanogaster. Highly significant differences among concentrations were detected for group I alcohols forD. simulans and group II alcohols for both species.D. simulans was more dependent on ethanol concentration thanD. melanogaster. There was also an alcohol by concentration interaction forD. simulans group I andD. melanogaster group II. At the common concentration (10%) there was no difference between the two species in their preference for any alcohol, with the following ranking order in attractiveness: methanol〉ethanol〉propanol 〉hexanol〉octanol〉butanol〉iso-propanol. There was a negative correlation between some physical properties of alcohols and their attractiveness. In general, the results are consistent with the “threshold response model.”
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  • 10
    ISSN: 1573-3297
    Keywords: oviposition behavior ; circadian rhythm ; Drosophila melanogaster ; photoperiodism ; genetic drift
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Under photoperiodic conditions, flies recently collected in nature exhibit, at the beginning of the scotophase, an oviposition peak which has a higher amplitude in Afrotropical than in European temperate populations. Several old laboratory strains failed, however, to show this peak. In each cross between genetically different strains, the oviposition curves of F1 and F2 were usually close to the midparent curve. Ten isofemale lines from an Afrotropical populations were submitted to inbreeding and drift. After 100 generations, two of the four surviving lines had retained the high peak typical of the origin population while the two others had lost it. Chromosome substitutions between these lines demonstrated a polygenic inheritance with a significant effect of the three major chromosomes. Presumably, the variations of amplitude of the oviposition peak were not caused by a modification of the ovarian activity but by a behavioral change toward the external signals of the environment.
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  • 11
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    Behavior genetics 14 (1984), S. 269-277 
    ISSN: 1573-3297
    Keywords: negative phototaxis ; artificial selection ; dispersal behavior ; habitat choice ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Population dispersal ofDrosophila melanogaster in the wild has been studied with the release and recapture of 60,000 flies from two photonegative selection lines and their photopositive control. The results show evidence of phototaxis-dependent habitat choice of at least one photonegative population. For this reason, phototactic behavior measured in Y mazes could be of evolutionary significance inDrosophila melanogaster.
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  • 12
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    Cell & tissue research 236 (1984), S. 279-288 
    ISSN: 1432-0878
    Keywords: Nucleoli ; Fibrillar centres ; Chromatin ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In embryonic cell-line derivative KCo of Drosophila melanogaster, the nucleolus, like most nucleoli, contains a small proportion of ribosomal DNA (1–2% of the total nucleolar DNA). The ribosomal DNA is virtually the only active gene set in the nucleolus and is found among long stretches of inactive supercoiled heterochromatic segments. We have demonstrated by use of a Feulgen-like ammine-osmium staining procedure that, depending on the state of growth, more or less fibres of decondensed DNA emanating from the intra-nucleolar chromatin (which is in continuity with the nucleolus-associated chromatin) ramify and unravel within the central nucleolar core to be transcribed. The nucleolus expands or contracts with the variation of activity and could belong to a supramolecular matricial structure such as is shown after extraction of the nuclei. After a long period of exposure to high doses of actinomycin D, the central nucleolar core became an homogeneous fibrous structure that could be interpreted as an aggregate of protein skeletal elements. The mechanism of repression and derepression of the nucleolar chromatin could thus be explained by a mechanism involving in part a sub-nucleolar structure. We propose a schematic organization of the nucleolar chromatin in KCo cells of Drosophila and discuss it in relation with other nucleolar organizations.
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  • 13
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    Development genes and evolution 192 (1983), S. 366-368 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Wing discs ; 20-Hydroxyecdysone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Full wing disc evagination requires about 10 h of continuous exposure to 20-hydroxyecdysone. The synthesis of two polypeptides is increased when wing discs are subjected to short exposure (4 h) to the hormone, and their synthesis is dependent on hormone. A second group of proteins increased in synthesis only after longer hormonal treatment (12 h); however, the increased synthesis of these proteins can be induced by withdrawing hormone after short exposure. The results of this study are consistent with the model of sequential gene activation by 20-hydroxyecdysone proposed by Ashburner et al. (1974).
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  • 14
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    Development genes and evolution 192 (1983), S. 103-107 
    ISSN: 1432-041X
    Keywords: Cell Surface ; Drosophila melanogaster ; 20-hydroxyecdysone ; protein changes ; Two-dimensional polyacrylamide gel electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Drosophila cell lines have provided popular material for study of the mechanisms by which steroid hormones regulate cellular events. Previous investigations at the organismic or organ level have suggested that ecdysteroids are bound by a cytoplasmic receptor, and that the resulting complex translocates to the nucleus where it results in active transcription of a few genes. The protein products of these primary responding genes then modulate a larger series of secondary transcriptional changes. In cultured cells, other investigators have detected the hormonally-induced synthesis of only 4–5 new polypeptides through 72 h of treatment. Although these proteins may represent the gene products associated with the primary response, this small number of changes is surprising in view of the rapid morphological alteration of the cells and changes in such surface-mediated behavior as substrate adhesion and agglutinability observed within the same time interval. In this report, we show that lactoperoxidase-catalyzed radioiodination followed by 2-dimensional polyacrylamide gel electrophoresis and autoradiography provide an effective protocol for visualizing cell surface proteins of a Drosophila cell line. Among the more than 175 labeled species detected, comparisons of control cells with those treated by 20-hydroxyecdysone for 72 h shows at least 27 differences. We interpret these differences as the result of the secondary transcriptional response to the hormone.
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  • 15
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    Development genes and evolution 192 (1983), S. 189-195 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Embryo Metabolism ; Protein biosynthesis ; Ovary ; Growth and development egg yolk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The accumulation of endogenously synthesized non-yolk proteins, and of exogenously derived yolk, was quantitated during oogenesis and embryogenesis ofDrosophila. Rates of non-yolk protein accumulation were calculated, and were correlated with polysome content at each developmental stage. Three distinct phases of non-yolk protein accumulation were observed: 1) relatively slow accumulation, lasting to stage 9 of oogenesis; 2) very rapid accumulation between stages 10 and 12 of oogenesis, when half of the protein of the mature egg is accumulated in less than 4 h; and 3) no further protein accumulation from stage 12 of oogenesis through at least the gastrula stage of embryogenesis. During phases 1 and 2, rates of non-yolk protein accumulation correlate well with the polysome content of egg chambers. Surprisingly, during the entire phase 3 the content of polysomes remains at high levels, even though no detectable protein accumulation occurs. This finding is in agreement with the low levels of protein synthesis that have been measured during early embryogenesis, and strongly suggests that late in oogenesis the efficiency of translation suddenly drops by about 20-fold. Moreover, our results imply that polysome content cannot always be directly correlated with protein synthetic activity.
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  • 16
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila melanogaster ; multiple forms ; conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The nature and the interconversion of the three multiple forms Adh-5, Adh-4, and Adh-3 of the purified alleloenzymes AdhS, AdhF, and AdhUF from the fruitflyDrosophila melanogaster have been examined. The experiments show that these multiple forms differ from those in crude extracts of flies homozygous at the Adh locus. On electrophoresis in a starch gel containing NAD or NADH, of purified AdhS which consists of the three Adh forms S-5, S-4, and S-3, five enzymatically active zones appear. This contrasts with the single active zone that arises with crude extracts. Of the five zones that appear with purified enzyme, S-5 gives rise to one, while the other four zones come from the two minor forms S-4 and S-3. The occurrence of the three multiple forms Adh-5, Adh-4, and Adh-3 for each of the purified alleloenzymes is considered due to Adh-5 and, in the case of Adh-4 and Adh-3, deamidation of Adh-5, with the Adh-3 fraction also containing some reversible modified Adh-5. Of the labile amides, at least one must be located in the coenzyme binding region with deamidation preventing coenzyme binding. Pure NAD does not convert Adh-5 to Adh-3 and Adh-1. To produce conversion, the presence of either acetone or butanone along with NAD is necessary. Increased amounts of either acetone or butanone result in increased conversion. In contrast to this, none of the carbonyl compounds cyclohexanone, (+)- and (−)-verbenone, acetaldehyde, acrolein, or crotonaldehyde produces conversion. The ketone group binds to the alcohol binding site in the enzyme-NAD complex. Conversion is considered due to the ketone group binding to a nucleophilic amino acid residue and forming a bridge to the C-4 of the nicotinamide moiety of NAD.
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  • 17
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; common and rare allozymes ; esterase-6 ; biochemical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The biochemical properties of three allozymes coded by theEst-6 locus, two common forms (EST-6S and EST-6F) and one rare form (EST-6VF), were studied. The results show the existence of differences in isoelectric point, activity, activation energy, Km, and temperature coefficient among the three variants, especially between the two common forms and the one rare form. The specific activity of the rare enzymatic variant seems to be less affected by temperature variation. The possible significance of these findings in relation to the mechanism of reproduction is briefly discussed.
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  • 18
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; esterase 6 ; isozymes ; enzyme kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Esterase-6 (EST 6; carboxylic-ester hydrolase; EC 3.1.1.1) from Drosophila melanogaster was purified to homogenity. Purified enzyme occurs as two closely moving isozymes, slow (EST 6S) and fast (EST 6F), on native polyacrylamide gel electrophoresis. Except for slight differences in their mobility, the two isozymes share similar molecular and catalytic properties. Both isozymes are glycoproteins and have an apparent molecular weight of 62,000 to 65,000 as judged by analytical gel filtration and sodium dodecyl sulfate (SDS) electrophoresis. They have identical mobility on SDS-polyacrylamide gels and an isoelectric point of 4.5. Each isozyme has a single active catalytic site as confirmed by titration with 0,0-diethyl-p-nitrophenyl phosphate (Paraoxon). We conclude that EST 6 is a monomeric enzyme. The amino acid composition of the two isozymes is very similar and both variants lack half-cystine residues. The low pI of the enzyme is due in part to a relatively high proportion of glutamic and aspartic amino acid residues. Characterization of the kinetic parameters of the isozymes using β-naphthyl and p-nitrophenyl esters revealed no statistically significant differences in catalytic efficiency. There is, however, a suggestion that the two isozymes may differ in their substrate specificity.
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  • 19
    ISSN: 1573-4927
    Keywords: two-dimensional electrophoresis ; Drosophila melanogaster ; yellow (y) gene ; protein purification ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Analysis of temperature-sensitive mutants suggests that the yellow (y) gene in Drosophila melanogaster is expressed at a different time in each cell type that gives rise to the various structures of the adult cuticle. An important step in analyzing the regulation of this gene requires identification of the y structural protein. A polypeptide has been identified which correlates with the presence or absence of a functional y gene. Furthermore, this protein has the tissue distribution profile expected of the y structural gene product. The ability to locate this gene was facilitated by the use of coisogenic stocks, two-dimensional electrophoretic protein separation, and an ultrasensitive silver protein stain.
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  • 20
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    Biochemical genetics 21 (1983), S. 49-62 
    ISSN: 1573-4927
    Keywords: glycerol-3-phosphate dehydrogenase ; enzyme synthesis ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Methods have been developed to measure the synthesis of glycerol-3-phosphate dehydrogenase (GPDH) during the development of Drosophila melanogaster. In emerged adult flies, GPDH is a principal component of protein synthesis, comprising between 1 and 2% of the protein synthetic effort. This high relative rate of protein synthesis continues throughout adult life during a period of stable enzyme concentration. Therefore, it is evident that GPDH undergoes continual turnover. Analysis of GPDH synthesis in the adult segments reveals that this enzyme is synthesized in head, thorax, and abdomen. In 5-day-old flies, the relative rates of GPDH synthesis in the thorax and abdomen are similar. However, the concentration of GPDH in the thorax greatly exceeds that found in the abdomen. Therefore, it appears that the turnover rate of GPDH in the abdomen must be greater than the turnover rate of GPDH in the GPDH-containing cells (flight muscle) of the thorax. GPDH represents between 0.5 and 0.9% of the protein synthetic effort of larvae. The principle GPDH-containing tissue of larvae is fat body. The turnover of GPDH in larvae is similar to that in adult abdomen. This may be related to the concurrent presence of GPDH isozyme-3 in both tissues. Our studies indicate that the cell type-specific control of GPDH occurs at several levels.
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  • 21
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila melanogaster ; multiple forms ; conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The nature and the interconversion of the three multiple forms Adh-5, Adh-4, and Adh-3 of the purified alleloenzymes AdhS, AdhF, and AdhUF from the fruitfly Drosophila melanogaster have been examined. The experiments show that these multiple forms differ from those in crude extracts of flies homozygous at the Adh locus. On electrophoresis in a starch gel containing NAD or NADH, of purified AdhS which consists of the three Adh forms S-5, S-4, and S-3, five enzymatically active zones appear. This contrasts with the single active zone that arises with crude extracts. Of the five zones that appear with purified enzyme, S-5 gives rise to one, while the other four zones come from the two minor forms S-4 and S-3. The occurrence of the three multiple forms Adh-5, Adh-4, and Adh-3 for each of the purified alleloenzymes is considered due to Adh-5 and, in the case of Adh-4 and Adh-3, deamidation of Adh-5, with the Adh-3 fraction also containing some reversible modified Adh-5. Of the labile amides, at least one must be located in the coenzyme binding region with deamidation preventing coenzyme binding. Pure NAD does not convert Adh-5 to Adh-3 and Adh-1. To produce conversion, the presence of either acetone or butanone along with NAD is necessary. Increased amounts of either acetone or butanone result in increased conversion. In contrast to this, none of the carbonyl compounds cyclohexanone, (+)- and (−)-verbenone, acetaldehyde, acrolein, or crotonaldehyde produces conversion. The ketone group binds to the alcohol binding site in the enzyme-NAD complex. Conversion is considered due to the ketone group binding to a nucleophilic amino acid residue and forming a bridge to the C-4 of the nicotinamide moiety of NAD.
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  • 22
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    Biochemical genetics 21 (1983), S. 49-62 
    ISSN: 1573-4927
    Keywords: glycerol-3-phosphate dehydrogenase ; enzyme synthesis ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Methods have been developed to measure the synthesis of glycerol-3-phosphate dehydrogenase (GPDH) during the development ofDrosophila melanogaster. In emerged adult flies, GPDH is a principal component of protein synthesis, comprising between 1 and 2% of the protein synthetic effort. This high relative rate of protein synthesis continues throughout adult life during a period of stable enzyme concentration. Therefore, it is evident that GPDH undergoes continual turnover. Analysis of GPDH synthesis in the adult segments reveals that this enzyme is synthesized in head, thorax, and abdomen. In 5-day-old flies, the relative rates of GPDH synthesis in the thorax and abdomen are similar. However, the concentration of GPDH in the thorax greatly exceeds that found in the abdomen. Therefore, it appears that the turnover rate of GPDH in the abdomen must be greater than the turnover rate of GPDH in the GPDH-containing cells (flight muscle) of the thorax. GPDH represents between 0.5 and 0.9% of the protein synthetic effort of larvae. The principle GPDH-containing tissue of larvae is fat body. The turnover of GPDH in larvae is similar to that in adult abdomen. This may be related to the concurrent presence of GPDH isozyme-3 in both tissues. Our studies indicate that the cell type-specific control of GPDH occurs at several levels.
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  • 23
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    Biochemical genetics 21 (1983), S. 375-390 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; segmental aneuploidy ; octanol dehydrogenase ; allozymes ; cytogenetic localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A gene-dosage effect is characteristic of eukaryotic structural genes and is therefore useful in gene mapping. However, attributing quantitative variations in enzyme activity to a gene-dosage effect or other putative regulatory loci can be suspect when the locus in question may be inducible by variations in culture conditions. The problem of controlling for allele-specific variations in activity and regulation can be circumvented in Drosophila melanogaster by the use of synthetic duplications and deficiencies in conjunction with enzyme polymorphism. A method for constructing segmental aneupliods heterozygous for electrophoretic variants of octanol dehydrogenase (Odh) is presented which permitted variations in allozyme phenotype and enzyme activity—which show a strict dosage dependency—to be produced simultaneously. The structural gene region for Odh was identified using T(Y;A) stocks and the deficiency M(3)S31 was used to assign the locus to polytene band region 86D1–4. With this method a segmental aneuploid survey of Drosophila for purposes of gene localization can be accomplished in one generation with appropriate stocks.
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  • 24
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; NADP+-dependent isocitrate dehydrogenase (NADP-IDH) ; cis-acting regulation ; population null alleles
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have characterized biochemical effects of Idh GB1 in Drosophila melanogaster. This is a “null”-activity allele for NADP+-dependent isocitrate dehydrogenase (NADP-IDH) isolated from a natural population. The homozygous mutant strain has 5% of the NADP-IDH specific activity found in controls and less than 24% of the immunologically cross-reacting material (CRM). This mutation maps to 27.2 on the third chromosome, to the right of h. The biochemical phenotype of this mutant strain includes a coordinate reduction in malic enzyme (ME) specific activity and CRM and an increase in specific activity for the pentose-phosphate shunt enzymes, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase. The K m values for purified NADP-IDH are not different from those found for the purified control enzyme for NADP+ or isocitrate. It is suggested that this allele may represent a cis-acting control mutation for one of at least two loci involved in the production of NADP-IDH in D. melanogaster.
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  • 25
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    Behavior genetics 13 (1983), S. 179-190 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; strain differences ; olfactory conditioning ; visual conditioning
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    Topics: Biology , Psychology
    Notes: Abstract Ten wild-type strains ofDrosophila melanogaster were used to compare performance in two different discriminative avoidance tasks, one involving odor as a discriminative stimulus and shock as the aversive stimulus and the other involving colored lights as the discriminative stimulus and vigorous shaking as the aversive stimulus. Significant strain differences were established for performance on both tasks. No significant correlation, however, was observed between performances on the two tasks; this suggests independent genetic control.
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  • 26
    ISSN: 1573-3297
    Keywords: foraging behavior ; larval ; selection ; Drosophila melanogaster ; D. simulans
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    Topics: Biology , Psychology
    Notes: Abstract A laboratory study is presented which shows that larval foraging behavior in the sibling speciesDrosophila melanogaster andD. simulans can respond rapidly (in six generations) to unidirectional selection. An apparatus was designed which selected for larvae which moved from nonnutritive agar medium to plugs of nutritive medium and remained feeding there. Larvae of the selected lines showed a correlated decrease in foraging path length which mirrored thesitter larval forager behavior type previously defined by Sokolowski [(1980).Behav. Genet. 10:291–302]. This supported the hypothesis that sitter larvae moved toward, and remained feeding on, a food source when they were not already utilizing one, whereasrover larvae foraged from food patch to food patch.
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  • 27
    ISSN: 1573-3297
    Keywords: foraging behavior ; pupation heights ; larval ; Drosophila melanogaster
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    Notes: Abstract Larvae which demonstrated long trails covering a large area while feeding (rover foragers) pupated significantly higher than those covering a relatively small area and exhibiting short paths (sitter foragers). Pupation height and density of larvae per vial were positively correlated. Under the condition of equal larval density per vial,rovers were found to pupate significantly higher thansitter larval foragers. The effect of three light regimes (constant light, constant darkness, and 12 h light followed by 12 h dark) indicated a more complex relationship between pupation height and larval foraging behavior.
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  • 28
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; common and rare allozymes ; esterase-6 ; biochemical properties
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    Notes: Abstract The biochemical properties of three allozymes coded by the Est-6 locus, two common forms (EST-6S and EST-6F) and one rare form (EST-6VF), were studied. The results show the existence of differences in isoelectric point, activity, activation energy, Km, and temperature coefficient among the three variants, especially between the two common forms and the one rare form. The specific activity of the rare enzymatic variant seems to be less affected by temperature variation. The possible significance of these findings in relation to the mechanism of reproduction is briefly discussed.
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    Biochemical genetics 21 (1983), S. 1153-1166 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; glucose-6-phosphate dehydrogenase
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Three alleles of the Zw locus of Drosophila melanogaster—Zw A, ZwB,and Zw lol—apparently code for dimeric, tetrameric, and monomeric forms of glucose-6-phosphate dehydrogenase (G6PD), respectively. The three forms of G6PD are characterized by different apparent K mvalues for glucose-6-phosphate but similar apparent K mvalues for NAPD+. When high concentrations of NAPD+ were added to enzyme preparations, the Zw Aand Zw lolforms of G6PD assumed tetrameric and dimeric properties, respectively. Although Zw loladults exhibit little G6PD activity, they maintain levels of G6PD-antigen comparable to those in Zw Aand Zw Badults. Thus the low level of G6PD activity in Zw lolindividuals cannot be explained as the consequence of lack of synthesis of the G6PD subunit.
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    Behavior genetics 13 (1983), S. 517-523 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; courtship ; homosexual behavior
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    Topics: Biology , Psychology
    Notes: Abstract In eightDrosophila melanogaster stocks, males which are only a few hours old stimulate courtship which is qualitatively and, in many of the stocks, quantitatively indistinguishable from the courtship elicited by virgin females. Although the sex appeal of young males and the extent to which it declines as the males become sexually mature vary somewhat from stock to stock, homosexual courtship appears to be characteristic of the species.
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    Theoretical and applied genetics 66 (1983), S. 221-223 
    ISSN: 1432-2242
    Keywords: Artificial selection ; Selection plateau ; Accumulation of lethals ; Sternopleural bristle number ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Four synthetic lines of D. melanogaster selected for low sternopleural bristle number for 50 generations were screened for lethals on chromosome III when their mean score equalled 2.5. Each line originated from a cross between line M (previously selected for the same trait during 130 generations) and a different unselected cage population. Line M was already known to carry a recessive lethal on chromosome III affecting the selected trait, such that the bristle score of the lethal heterozygote was lower than that of the viable homozygote. Tests revealed 18 lethals, 15 of these present in at least two lines. Each line carried from 10 to 16 lethals. All lines carried groups of lethals present on the same chromosome, and at least six lethals in each line were included in such an association with a frequency of 0.18 or higher. It appears that the lethal affecting bristle score in line M has protected a segment of chromosome III from natural selection and that the remaining 14 lethals have accumulated later in that line.
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  • 32
    ISSN: 1432-0878
    Keywords: Antennal sensilla ; Central projections ; Antennal glomeruli ; Orthograde cobalt diffusion ; Drosophila melanogaster
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    Topics: Biology , Medicine
    Notes: Summary Cobalt fills from small, defined regions of the antenna in D. melanogaster show that the three types of sensilla on the third segment, the flagellum, and a fourth sensillum located in the arista, project into the glomeruli of the antennal lobe. We have identified 19 glomeruli in each lobe, according to their location, shape, and size. At least ten of these represent major projection areas of flagellar or aristal sensilla. The large majority of glomeruli is innervated from both antennae, but a small group of five receive exclusively ipsilateral input. A particular sensory fiber appears to terminate only in one specific glomerulus, either in the ipsilateral or in both lobes. Fills from flagellar regions bearing a single type of sensillum, yield a specific pattern of glomeruli containing stained terminals. Aristal projections remain strictly ipsilateral, whereas those from the other sensilla consist of an ipsilateral and a bilateral component. When filling from different points in an area bearing one type of sensillum, similar projections are produced, suggesting that projection patterns observed reflect predominantly the type of sensillum rather than its location on the flagellum. Accordingly, individual glomeruli might represent functional units, each receiving antennal input in a characteristic combination.
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    Development genes and evolution 191 (1982), S. 257-263 
    ISSN: 1432-041X
    Keywords: Juvenile hormone ; Precocene ; Drosophila melanogaster ; Oocyte degeneration
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    Topics: Biology
    Notes: Summary It is known from previous work that juvenile hormone (JH) is required to initiate vitellogenin uptake into maturing oocytes ofDrosophila melanogaster, but additional requirements for this hormone during oocyte maturation have not been fully understood. To determine if early vitellogenic oocytes (stages 8 and 9) require JH for continued development, these oocytes were transplanted toDrosophila female and male hosts which were rendered deficient in JH by three methods. Implanted stage 9 and usually stage 8 oocytes were found to degenerate in JH-deficient hosts unless ZR-515, a JH analogue, was applied to the host shortly after implantation. These results were confirmed during in situ ovary development. JH deficiency was produced in gravid females, and ovaries examined at subsequent time intervals were found to be deficient in stage 8–10 oocytes as early as 6 h after treatment. Degenerating oocytes corresponding to these stages were commonly found. ZR-515 prevented oocyte degeneration during at least the first 8 h and continued to support stage 8–10 oocyte development 24 h after application to these females. The results suggest that JH is required not only for initiation but also for continuation of vitellogenin uptake and oocyte development.
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    Development genes and evolution 191 (1982), S. 331-334 
    ISSN: 1432-041X
    Keywords: Genetic mosaics ; Cell autonomy ; Cell affinities ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary InDrosophila melanogaster, segmental specification takes place in groups of cells around the blastoderm stage. This segmental specification requires the function of the genes of the bithorax-complex. We have studied preblastoderm mosaics (gynandromorphs) of mutant (bx 3,pbx, Ubx, Ubx 80) and wildtype (heterozygotes for these alleles) cells. The results show a total cell autonomy in the differentiation of both wildtype and homoeotially transformed cells. However, several unexpected phenotypes were found. They are discussed in terms of the function of the bithorax genes and early interactions between mutant and wildtype territories.
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  • 35
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    Development genes and evolution 191 (1982), S. 381-384 
    ISSN: 1432-041X
    Keywords: Polyteny ; DNA content ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary The amounts of DNA in midgut and Malpighian tubule cells of adult maleDrosophila melanogaster have been determined by Feulgen-DNA cytophotometry. The DNA values fall into discrete classes reflecting different levels of polyteny. The maximum level is 64C in the midgut, 256C in Malpighian tubules, and the modal values are 32C and 128C respectively. The data provide no evidence for extensive underreplication of heterochromatin. It is suggested that the reduced amount of satellite DNA found in the tissues of young adult flies may be a consequence of the fact that cycles of DNA replication started in the pre-adult stages are not completed until some hours after eclosion.
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    Biochemical genetics 20 (1982), S. 1117-1129 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; amylase ; dietary effects ; enzyme quantity
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The level of amylase activity in larvae and adults of Drosophia melanogaster is dependent on the dietary carbohydrate source; flies or larvae from a food medium containing starch show higher levels of activity than individuals from a food containing simple sugars. This is shown to be due to repression of activity by sugars rather than enhancement of activity by starch. Moreover, the changes in enzyme activity reflect a change in enzyme quantity rather than a change in catalytic efficiency. The seeming stimulation of amylase activity by sucrose in some experiments is due, simply, to comparisons with “starvation” diets which cause a large nonspecific reduction in enzyme activity. Though all strains tested showed repression of enzyme activity by simple sugars, the degree of repression varies between strains. Also, in those strains which carry a duplication of the amylase structural gene, the two isozymal forms of amylase can be differentially repressed by dietary sugars.
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    Biochemical genetics 20 (1982), S. 607-619 
    ISSN: 1573-4927
    Keywords: orotic acid ; pyrimidine biosynthesis ; Drosophila melanogaster
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Flies mutant for one or both of the last two enzymes of de novo pyrimidine biosynthesis express a number of phenotypes that are also expressed by mutants of the first four pathway enzymes (r and Dhod-null mutants). However, r-1 flies also express two phenotypes, mottled eyes and poor viability, that are not usually expressed by r and Dhod-null flies. Chemical determinations show that orotic acid, a substrate for the fifth pathway enzyme, accumulates in r-1 individuals but not in r and wild-type individuals. Moreover, flies simultaneously mutant for r and r-1 do not express the mottled-eye phenotype, showing that r is epistatic to r-1 for this r-1-specific phenotype. When genotypically wild-type flies are cultured on a medium containing 6-azauracil, the base of a potent inhibitor of the last enzyme of de novo pyrimidine biosynthesis, phenocopies are obtained that include the mottled-eye as well as the wing phenotypes of r-1 flies. These results support hypotheses that the phenotypes common to r, Dhod-null, and r-1 flies are consequences of uridylic acid deficiency, whereas the r-1-specific phenotypes result from orotic acid accumulation in flies lacking either or both of the last two enzymes of de novo pyrimidine biosynthesis.
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  • 38
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    Biochemical genetics 20 (1982), S. 747-761 
    ISSN: 1573-4927
    Keywords: allozymes ; geographic races ; Drosophila melanogaster ; adaptation
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allelic frequencies at five polymorphic loci were determined in seven European and six Afrotropical populations of Drosophila melanogaster. African populations, which may be considered as ancestral for the species, showed a greater genetic diversity as measured by the number of alleles found. Within each geographic group (Europe or tropical Africa) genetic distances between local populations were very small (D=0.027). By contrast, the average distance between European and African populations (D=0.389) was more than 12 times bigger. It was previously known that various morphological or physiological differences, which probably reflect genetic adaptations to different environments, exist between these temperate and tropical populations. Data presented here suggest that the divergence in allozyme frequencies also reflects some selective mechanisms.
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  • 39
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; sexual behavior ; behavioral mutant ; temperaturesensitive mutation
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    Topics: Biology , Psychology
    Notes: Abstract NormalDrosophila melanogaster males rapidly react to changes in the mobility of mutantshibire ts females by performing less courtship when the females are paralyzed and by courting movingshibire ts females vigorously. Mutantoptomotor-blind males, which are unable to respond to certain horizontally moving patterns, sustain abnormally short courtship bouts when tested with normal females, almost never perform orientation, one of the courtship behaviors, and require more time to initiate copulation than normal males. These results suggest that males must perceive female movement to perform normal courtship and copulation. Normal females become stationary before copulation occurs. Normal males mate quickly in response to this change in female behavior, while blind males require more time to effect copulation, prolonging the time that the female remains stationary. Mutantsmellblind females, which do not respond to certain odors, continue to move during the time that they are courted by normal or blind males and also require more time to copulate, suggesting that females may stop moving before mating in response to olfactory cues.
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    Theoretical and applied genetics 62 (1982), S. 289-293 
    ISSN: 1432-2242
    Keywords: Interocellar bristles ; Drosophila melanogaster ; Disruptive selection ; Mating system
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    Topics: Biology
    Notes: Summary A population of Drosophila melanogaster has been exposed to disruptive selection for interocellar bristle number for fifteen generations. Two different mating systems have been employed: quasi-random and mating-choice. The expected results of an increase in phenotypic variance and divergence of extreme mating groups were not found when the mating-choice system was used, while a clear divergence (2.04% of overlap) was found at the end of the experiment in one line where the quasi-random system (QR1) had been used. A possible explanation for our results, which is also suggested by those of several other authors, could be that of hybrid vigor. Thus, the reason for the absence of effect in MCh may be that the progeny of “hybrid” matings are likely to be less inbred and therefore have higher viability, mating ability and egg production.
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  • 41
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    Theoretical and applied genetics 62 (1982), S. 89-96 
    ISSN: 1432-2242
    Keywords: Population genetics ; Drosophila melanogaster ; Multiple mating ; Alcohol dehydrogenase
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    Topics: Biology
    Notes: Summary Mother-offspring data for alcohol dehydrogenase genotypes of a vineyard cellar population of D. melanogaster are best explained by a model that allows 21% of females in the population to mate twice with an 83% level of sperm displacement. A population model with multiple mating and sperm displacement is examined theoretically. A formula for the effective population size is derived under this model. Multiple mating increases the effective population size relative to single mating.
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  • 42
    ISSN: 1432-041X
    Keywords: Salivary gland ; Protein synthesis ; Larval development ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Patterns of protein synthesis in the salivary glands ofDrosophila melanogaster have been studied throughout late larval and prepupal development by pulse labelling the tissues with35S-methionine. Specific changes to the pattern of proteins synthesized during development are found and the significance of these changes is discussed in view of the known changes in gene (puffing) activity which occur at the same times. We review the problem of salivary gland function in “prepupal”Drosophila.
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  • 43
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    Development genes and evolution 190 (1981), S. 226-229 
    ISSN: 1432-041X
    Keywords: Early neurogenesis ; Mutants ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Embryonic lethal mutations at the Notch locus are known to produce a conspicuous central nervous system hypertrophy accompanied by a hypotrophy of the epidermal sheath. We have studied several zygotic mutants belonging to four different autosomal complementation groups which produce the same phenotype. The embryonic development of the new mutants, as well as that of Notch, consists of an initial enlargement of the neurogenic region at the expenses of epidermal cell precursors. The possibility is discussed that these five loci are involved in the determination of neural and epidermal cell precursors.
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  • 44
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    Development genes and evolution 190 (1981), S. 237-240 
    ISSN: 1432-041X
    Keywords: DNA replication ; Polytene salivary gland nuclei ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Combined cytophotometric and autoradiographic experiments are performed on individual polytene salivary gland nuclei of X/X-female and X/Y-male larvae ofDrosophila melanogaster, DNA measurements of unlabeled nuclei reveal complete douplings of all 4C DNA quantity during polytenization. These new data do not agree with the hypothesis of heterochromatic underreplication.
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  • 45
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    Development genes and evolution 190 (1981), S. 365-369 
    ISSN: 1432-041X
    Keywords: Selector genes ; Determination ; Homoeotic mutations ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary New alleles of thetrithorax locus have been isolated and analysed. The phenotypes of different allelic combinations confirm that a decrease or loss of function of the locus is responsible for homoeotic transformations of the adult thoracic and abdominal segments. Since neither these homoeotic transformations nor larval lethality are complemented by the previously described mutationRg-bx, it is concluded that the latter is an allele oftrithorax. The effect of near loss of function of thetrithorax locus after the completion of embryogenesis has been investigated by clonal analysis. This has produced two unexpected results: 1) there is a requirement for the activity of the locus after embryogenesis is completed; 2) the locus is required for the normal development of at least some mesothoracic structures. These results are discussed with respect to the selector gene hypothesis and other putative activator gene mutations.
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    Biochemical genetics 19 (1981), S. 15-30 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; RNA polymerase ; adults
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In preparation for the isolation and biochemical characterization of putative RNA polymerase mutants, DNA-dependent RNA polymerases of Drosophila melanogaster adults were isolated and partially characterized. Approximately 70% of the female adult RNA polymerase is located in ovaries. Multiple forms of ovarian RNA polymerases I and II are separable by DEAE-Sephadex chromatography. The two forms of RNA polymerase II differ in ammonium sulfate optima. RNA polymerase IIA is more active with double-stranded DNA as template, whereas RNA polymerase IIB transcribes single-stranded DNA most efficiently. Rechromatography of RNA polymerase IIA on DEAE-Sephadex results in the loss of ability of this form to transcribed double-stranded DNA most efficiently. Ovariectomized carcasses have two forms of RNA polymerase I and one form of RNA polymerase II and each transcribes single-stranded DNA most efficiently. As judged by gel filtration chromatography, female adult extracts have forms of RNA polymerase II that differ in molecular weight and template preference.
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    Biochemical genetics 19 (1981), S. 47-60 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; aminopeptidases ; leucine aminopeptidases
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two leucine aminopeptidases from Drosophila melanogaster larvae have been partially purified. The LAP A and D enzymes have similar biochemical characteristics including molecular weights of ≅280,000 daltons, Michaelis-Menten constants of ≅0.05 mM, associations with metal cofactors, and specificities toward natural and chromogenic substrates. They differ in their pH optima and spatial distributions. If the closely linked genes that code for these enzymes have resulted from a tandem gene duplication event, it is suggested that there has been subsequent evolutionary divergence. This would provide Drosophila larvae with two related, but functionally distinct enzymes.
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  • 48
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; RNA polymerase ; mutants
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    Notes: Abstract A method for assaying Drosophila melanogaster adult DNA-dependent RNA polymerase II in crude extracts from as few as two females or three males is described. Preparation of the extracts involves incubating homogenates at 25 C for 60 min and subsequent treatment with Macaloid. Eighty-five percent of the activity in the extracts is inhibited by 1 µg/ml α-amanitin and this fraction is attributed to RNA polymerase II. RNA polymerase II activity in the extracts shows a good dose dependence and a partial dependence on added DNA, Mn2+, and all four ribonucleoside triphosphates. The kinetics of heat inactivation of RNA polymerase II in crude extracts could be reproducibly measured. Flies of different genotypes had different initial rates of RNA polymerase II heat inactivation. The isolation of Drosophila melanogaster α-aminitin-resistant mutants is also reported. Using the assay described in this paper, it appears that the basis for the resistance is an altered RNA polymerase II. The mutation has been mapped to the third chromosome by chromosome replacement.
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    Biochemical genetics 19 (1981), S. 1211-1221 
    ISSN: 1573-4927
    Keywords: brown pigment ; Drosophila melanogaster ; phenoxazinone synthetase
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Nonenzymatic and enzymatic catalysis of the oxidation of 3-hydroxykynurenine (and 3-hydroxyanthranilic acid) has been studied and characterized in Drosophila extracts, clearing up some of the confusion surrounding the synthesis of the brown eye pigment, xanthommatin. The genetic basis of the terminal steps in pigment synthesis remains obscure, since all mutants tested have full synthetase activity.
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    Biochemical genetics 19 (1981), S. 277-299 
    ISSN: 1573-4927
    Keywords: substrate specificity ; pseudopolymorphism in lactate dehydrogenase ; alcohol dehydrogenase ; Drosophila melanogaster
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An electrophoretic variant in the LDH (l-lactate:NAD oxidoreductase, E.C.1.1.1.27) of Drosophila melanogaster was observed on starch (or polyacrylamide) gels. This variant was found to exhibit an identical isozymic pattern (three isozymes with a decreasing staining density) on starch gel and map position as the Adh locus. On the other hand, anodal polyacrylamide gel electrophoresis in crude extracts has shown LDH to consist of nine bands and ADH of four bands. We have shown that ADH (Alcohol:NAD oxidoreductase, E.C.1.1.1.1) also oxidizes l(+)-lactate or d(−)-lactate with the NAD, while LDH oxidizes ethanol. By using various genetic and biochemical techniques, we have shown that the observed Ldh electrophoretic variant was not a real one and could be attributed to the presence of ADH. We have called this phenomenon “pseudopolymorphism,” and the problem of enzyme specificity has been examined. The appearance of a band in an assay using lactic acid as a substrate is not sufficient evidence for the presence of LDH. Hence, caution is called for before characterizing an electrophoretic band on a gel as being equivalent to the presence of a genetic locus. Out of the nine electrophoretic zones of activity observed on polyacrylamide gel (or out of the six previously observed) using crude extract, only two (one major and one minor) belong to LDH, as revealed by purified enzyme preparations. Furthermore, purified LDH exhibits activity in two bands on starch gel (out of three observed in crude extracts), which appear in different positions as compared with those of ADH. Finally, one band which responds to the presence of d(−)-lactate but not to l(+)-lactate has been revealed.
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    Theoretical and applied genetics 59 (1981), S. 251-263 
    ISSN: 1432-2242
    Keywords: Drosophila melanogaster ; Rare allele ; Dynamic behaviour ; Asymmetrical selection response ; Changes in heritability
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    Topics: Biology
    Notes: Summary An initially rare allele with a large effect on a quantitative character is expected to exhibit the following behaviour in artificial selection lines: 1. It should change in frequency, or be lost by chance, at rates predictable from the effects of the allele on the quantitative character and the selection regime imposed. 2. At the phenotypic level the behaviour of the allele should cause (a) asymmetrical responses to bidirectional selection, (b) variation among replicate lines in response to selection corresponding to the behaviour of the allele in individual lines, (c) changes in heritability in lines in which the allele increases in frequency and (d) selection response compatible with the effects of the allele. This paper reports an experimental evaluation of these predictions utilizing a rare allele of large effect (sm lab ) detected in a sample of the Canberra outbred population of Drosophila melanogaster at a frequency of 1/120. Homosygosity for this allele reduced abdominal bristle number by more than 50%, altered the abdominal bristle pattern and reversed the sexual dimorphism for abdominal bristle number. Experiments were done to characterise sm lab and all evidence indicates that it is a single allele with a very large effect. Bidirectional selection for abdominal bristle number was carried out in three high and three low lines from this sample of the Canberra population. The sm lab allele rose in frequency and went to fixation in two of the low lines (in 10 generations) but was lost from the third. These times to fixation were slower than the expectations derived from computer simulations of the behaviour of such an allele but this can be attributed to the lower fitness of sm lab homozygotes. The proportions of lines with the allele fixed or lost were compatible with expectations. At the phenotypic level, the behavior of sm lab had the expected consequences, namely, (i) asymmetrical responses to bidirectional selection, (ii) variation in response among replicate low lines corresponding to the behaviour of sm lab , (iii) changes in heritabilities in the lines in which sm lab went to fixation, and (iv) selection responses compatible with the effects of the allele. A test for rare alleles of large effect was proposed, based on the expected pattern of change in heritability under artificial selection. This test was applied to the high selection lines but no evidence was found for important effects due to rare alleles of large effect increasing abdominal bristle number, a conclusion consistent with other independent evidence. This work provides experimental corroboration of the links between population genetics and quantitative genetics.
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  • 52
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    Theoretical and applied genetics 60 (1981), S. 317-327 
    ISSN: 1432-2242
    Keywords: Artificial selection ; Selection for wing length ; Correlated responses to selection ; Allozyme systems ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Significant changes of genotypic structure in 20 lines selected for wing length are detected by analysis of the allelic frequencies of several enzyme loci (XDH, LAP-D, EST-6, 1-APH, ADH, α-GPDH). These changes are not haphazard but a consequence of the effects of selection on the genetic structure of the population, since replicate lines always behave in a parallel way. The changes are larger in the lines selected for short wings, in which the genetic variability decreases considerably. This decrease is the result of selection for homozygosity, detected at the allozyme loci, but most probably reflects homozygosity of more or less extended chromosomal segments. Selection for wing length, especially for short wings, favoured recombinants of the initial founder chromosomes. Only in the 1-APH and the EST-6 loci, separated by 11.7 centimorgans on the genetic map, do the alleles linked in the founder lines change in parallel in the control and long wing lines. The correlated response in the allozyme allele frequencies cannot be accounted for by a direct influence of the allozymes on the variability in wing length. The changes in the EST-6, 1-APH and perhaps in the LAP-D, can be explained by a direct effect of natural selection on the allozyme loci, probably in interaction with the effect of selection for wing length on linked loci. This last effect seems to be the main factor contributing to the change detected in the XDH locus.
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  • 53
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    Cell & tissue research 216 (1981), S. 513-523 
    ISSN: 1432-0878
    Keywords: Internal taste sensilla ; Sensory projections ; Cobalt diffusion ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Phase-contrast microscopy of 2.5 μm plastic sections reveals five different kinds of sense organs on the internal mouthparts of Drosophila melanogaster: a ventral group of sensilla on the epipharynx, three kinds of sense organs in the middle part of the sucking apparatus (the cibarium), one of them being described here for the first time, and an additional type of sensillum in the dorsal pharynx (Fig. 1). Three of these internal sense organs resembling each other structurally form similar projection patterns in the tritocerebrum, whereas external taste receptors on the labial palps show a different pattern in the suboesophageal ganglion (Fig. 12). The central projections of these internal and external sensilla were traced by applying an ethanolic solution of cobalt on the intact cuticle.
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  • 54
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; esterase 6 activity ; esterase 6 ; null allele ; remating ; fitness
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    Topics: Biology , Psychology
    Notes: Abstract Esterase 6 (EST 6) inDrosophila melanogaster is a male reproductive enzyme transferred to females as a component of the seminal fluid [Richmond, R. C., Gilbert, D. G., Sheehan, K. B., Gromko, M. H., and Butterworth, F. W. (1980).Science 207:1483–1485]. Here we report investigations into the relation between EST 6 and remating by females. EST 6 activity in a strain selected for decreased time to remating is increased over control levels. Inseminated females remated to males carrying null or active alleles show no differences in the timing of remating. However, females inseminated by EST 6-active males remate significantly sooner than females inseminated by null males. Interrupted copulation experiments demonstrate that the remating effect is not due to EST 6 alone but requires other components of the ejaculate. Other evidence suggests that sperm stored in the ventral receptacle respond to EST 6 levels and control remating time. As the first mate of a female who will remate, null-EST 6 males have, under laboratory conditions, a significantly higher fitness than males carrying active alleles. Thus the absence of null alleles of EST 6 in natural populations presents a dilemma suggesting that the remating effect of EST 6 may be balanced by other effects on reproduction.
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  • 55
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    Development genes and evolution 188 (1980), S. 127-132 
    ISSN: 1432-041X
    Keywords: Pole cell isolation ; Maternal effect mutants ; Drosophila melanogaster
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    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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  • 56
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; choice of oviposition site ; strain difference ; site discrimination ; egg insertion ; selection ; wild type
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    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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  • 57
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    Behavior genetics 10 (1980), S. 163-170 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; mating success ; male fertility ; male age ; female choice experiments
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    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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    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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  • 59
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; 6-phosphogluconate dehydrogenase ; isozyme
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    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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  • 60
    ISSN: 1573-4927
    Keywords: Tryptophan ; kynurenine ; white ; Drosophila melanogaster ; amino acid transport ; Malpighian tubules
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    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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    Biochemical genetics 18 (1980), S. 303-309 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; allozymes ; GPT ; genetic mapping
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    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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  • 62
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    Biochemical genetics 18 (1980), S. 699-715 
    ISSN: 1573-4927
    Keywords: modifying genes ; G6PD activity ; 6PGD activity ; Drosophila melanogaster ; enzyme polymorphism
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    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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    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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    Behavior genetics 10 (1980), S. 183-190 
    ISSN: 1573-3297
    Keywords: ethanol ; Drosophila melanogaster ; larvae ; strain difference ; habitat selection ; isofemale strains
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    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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  • 65
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; Drosophila simulans ; hybrid behavior ; transition analysis ; courtship sequences
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    Topics: Biology , Psychology
    Notes: Abstract Several transitions between sequential male courtship elements were analyzed forDrosophila melanogaster its close relativeD. simulans, and two types of hybrid males. Hybrid males from special reciprocal crosses did not differ. WhileD. melanogaster andD. simulans males differed markedly for the majority of transitions studied, hybrid males showed no consistent pattern with the parent species, being indistinguishable fromD. simulans males, indistinguishable fromD. melanogaster, or intermediate between them, depending on the trait observed. This suggests independent genetic control of these transitions during male courtship.
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  • 66
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    Theoretical and applied genetics 56 (1980), S. 161-173 
    ISSN: 1432-2242
    Keywords: Drosophila melanogaster ; Chromosome ; Spontaneous interchange ; half-translocation ; Non-homologous pairing ; Mitosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Herein is described an attempts to establish chromosome pairing-interchange relationships in Drosophila melanogaster female. For this purpose, the formation of half-translocations was studied in XXY and XX females bearing compounds of the second pair of autosomes. With respect to XXY females, it was expected that the free Y chromosome would pair with these compounds and that half-translocations involving 2L would arise. In as much as compound chromosomes in XX females had no partner for pairing, the formation of half-translocations involving 2L was not expected. Half-translocations were registered in the F1 from crosses of XX and XXY females to b j pr cn/T(Y;2)C males. The cross was designed to permit the detection of very rarely occurring non-homologue interchanges. Offspring number was 335 in XX females and 550 in XXY females. The majority of offspring consisted of individuals arisen from the spontaneous restitution of compounds and the formation of 2n egg cells. Based on phenotype, the offspring of XX females contained 4 individuals with half-translocations involving 2L; there were 48 such flies among the offspring of XXY females. As confirmed by progeny analysis, 38 half-translocations occurred in XXY females and none in XX females. Of the 31 spontaneous interchanges in XXY females 28 were recorded between the Y and the left compound, one between the Y and the right compound, and one between the X and the left compound. Non-homologue interchanges were of oogonial origin judging by the fact that individuals with half-translocations arose in clusters. Unlike Y — left compound interchanges, the interchanges between autosomal compounds seem to be of meiotic origin.
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    Theoretical and applied genetics 57 (1980), S. 25-32 
    ISSN: 1432-2242
    Keywords: Long-term selection ; Residual genetic variability ; Heritability ; Abdominal bristle number ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Six replicate lines of Drosophila melanogaster, which had been selected for increased abdominal bristle number for more than 85 generations, were assayed by hierarchical analysis of variance and offspring on parent regression immediately after selection ceased, and by single-generation realised heritability after more than 25 generations of subsequent relaxed selection. Half-sib estimates of heritability in 5 lines were as high as in the base population and much higher than observed genetic gains would suggest, excluding lack of sufficient additive genetic variance as a cause of ineffective selection in these lines. Also, there was considerable diversity among the six lines in composition of phenotypic variability: in addition to differences in the additive genetic component, one or more of the components due to dominance, epistasis, sex-linkage or genotype-environment interaction appeared to be important in different lines. Even after relaxed selection, single-generation realised heritabilities in four lines were as high as in the base population. As a large proportion of total genetic gain must have been made by fixation of favourable alleles, the compensatory increase of genetic variability has been sought in a genetic model involving genes at low initial frequencies, enhancement of gene effects during selection and/or new mutations.
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    Theoretical and applied genetics 57 (1980), S. 113-117 
    ISSN: 1432-2242
    Keywords: Long-term selection ; Relaxed selection ; Reverse selection ; Dominance of bristle number genes ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Reverse and relaxed selection were carried out in sublines which were derived from six replicate lines of Drosophila during 86–89 generations of selection for increased abdominal bristle number, and the reverse selection sublines were reciprocally crossed with selection lines of their origin. The results of serial relaxed selection initiated at different generations of selection confirm that the accelerated responses observed in the selection lines were largely due to deleterious genes, particularly lethals, with large effects on the selected character. The decline in mean bristle number under relaxed selection was not much different between crowded and uncrowded relaxed sublines. Reverse selection initiated at generation 57 was very effective, though it failed to bring the mean back to the base population level, and the genetic differences between replicate sublines (two from each of the six lines) indicate that low bristle number genes were probably rare in the selection lines. The genes which were still segregating after 57 generations of selection, on the average, did not show any directional dominance. The contribution of the X-chromosome to selection response was proportional to its chromosome length.
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    Theoretical and applied genetics 57 (1980), S. 247-255 
    ISSN: 1432-2242
    Keywords: Compound ; free-arm strains ; Drosophila melanogaster ; Unstable genetic isolation
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    Topics: Biology
    Notes: Summary Crosses between compound-2L; free-2R (free-arm) and standard strains of Drosophila melanogaster produce two classes of inviable aneuploid hybrids in equal proportions: monosomic 2L and trisomic 2L. The lethal period for monosomics occurs during embryogenesis while the trisomics survive to late pupae. Since the hybrids are inviable, standard and free-arm strains within a mixed population remain genetically isolated. Genetic isolation in the absence of mating isolation offers an extreme example of unstable equilibrium. Relative fitness data indicate that an unstable equilibrium will be established between free-arm and standard strains at a ratio of 2.5∶1. Indeed, in three cage experiments established at initial ratios of 3∶1, free arms to standards, laboratory (Oregon R) or native (Okanagan S) standard strains were completely replaced in approximately 100 days by free-arm lines derived either from laboratory or from native genetic background. In contrast, one cage established at an initial ratio of 4∶1 failed to show replacement and for 92 days remained at approximately the initial ratio. Subsequent genetic analysis of flies removed from this cage identified the presence of an anomalous strain through which genetic information was transferred reciprocally between the free-arm and standard lines. The second chromosomes carried by this strain consisted of a free-2R and a standard second on the right arm of which was attached a duplication for all of 2L. While the origin of the 2L·2R+2L chromosome was uncertain, genetic and cytological examinations revealed that it represented the reciprocal crossover product expected from an exchange that generated a F(2R). Additional crosses disclosed that the transmission frequency of the asymmetrical pair of second chromosomes, as well as their right-arm crossover products, was disproportionately in favor of the short arm. Since unequal transmission was invariably greater from female parents, this phenomenon was viewed as further evidence in support of the drag hypothesis.
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  • 70
    ISSN: 1573-3297
    Keywords: mating success ; allozyme polymorphism ; overdominance ; mating latency ; Adh locus ; Drosophila melanogaster ; rare genotype mating advantage ; alcohol dehydrogenase ; statistical methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Strains ofDrosophila melanogaster having different alcohol dehydrogenase (Adh) genotypes (FF, FS, or SS) were assembled in a mating chamber in varying ratios, and the mating successes were recorded. In experiments with a 25∶25 ratio, theFF males succeeded in mating more than didFS andSS males, while theFS males surpassed theSS males. As for the females,FF also surpassedSS. In experiments with a 5∶45 or 45∶5 ratio, some differences from the 25∶25 ratio occurred, but in these cases the rare genotypes were at a disadvantage. In one case, female genotypes (FF vs.SS) displayed a difference in mating latency time, but male genotypes did not. The findings did not suggest that rare genotype mating advantage and overdominance in mating success play a role in the maintenance of theAdh polymorphism.
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    Behavior genetics 10 (1980), S. 291-302 
    ISSN: 1573-3297
    Keywords: foraging strategies ; chromosomal analysis ; Drosophila melanogaster ; larvae ; feeding-locomotor behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Two larval foraging strategies inDrosophila melanogaster were identified, “rover” and “sitter.” “Rovers” traverse a large area while feeding whereas “sitters” cover a small area. The difference between “rovers” and “sitters” was analyzed genetically by chromosomal substitutions between isogenic stocks. Differences in larval locomotor behavior (“crawling behavior”) can be attributed to the second chromosome, the “rover” strategy being dominant over the “sitter” strategy. Differences in feeding rate (“shoveling behavior”) are affected additively by both the second and third chromosomes. Natural populations ofDrosophila larvae were sampled three times over a 2-month period; “rovers” and “sitters” were at constant frequencies in these populations. The two foraging strategies are discussed in the light of resource utilization in environments where food is distributed continuously or discontinuously.
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    Development genes and evolution 187 (1979), S. 151-165 
    ISSN: 1432-041X
    Keywords: Oogenesis ; Embryogenesis ; Two-dimensional gels ; Protein synthesis ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Protein synthesis in egg follicles and blastoderm embryos ofDrosophila melanogaster has been studied by means of two-dimensional gel electrophoresis. Up to 400 polypeptide spots have been resolved on autoradiographs. Stage 10 follicles (for stages see King, 1970) were labelled in vitro for 10 to 60 min with35S-methionine and cut with tungsten needles into an anterior fragment containing the nurse cells and a posterior fragment containing the oocyte and follicle cells. The nurse cells were found to synthesize a complex pattern of proteins. At least two proteins were detected only in nurse cells but not in the oocyte even after a one hour labelling period. Nurse cells isolated from stages 9, 10 and 12 follicles were shown to synthesize stage specific patterns of proteins. Several proteins are synthesized in posterior fragments of stage 10 follicles but not in anterior fragments. These proteins are only found in follicle cells. No oocyte specific proteins have been detected. Striking differences between the protein patterns of anterior and posterior fragments persist until the nurse cells degenerate. In mature stage 14 follicles, labelled in vivo, no significant differences in the protein patterns of isolated anterior and posterior fragments could be detected; this may be due to technical limitations. At the blastoderm stage localized synthesis of specific proteins becomes detectable again. When blastoderm embryos, labelled in vivo, are cut with tungsten needles and the cells are isolated from anterior and posterior halves, differences become apparent. The pole cells located at the posterior pole are highly active in protein synthesis and contribute several specific proteins which are found exclusively in the posterior region of the embryo. In this study synthesis of specific proteins could only be demonstrated at those developmental stages which are characterized by the presence of different cell types within the egg chamber, while no differences were detected when stage 14 follicles were cut and anterior and posterior fragments analyzed separately. The differences in the pattern of protein synthesis by pole cells and blastoderm cells indicate that even the earliest stages of determination are reflected by marked changes at the biochemical level.
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    Development genes and evolution 187 (1979), S. 167-177 
    ISSN: 1432-041X
    Keywords: Pyrimidine biosynthesis ; rudimentary mutants ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The X-linkedrudimentary (r) mutants ofDrosophila melanogaster are pyrimidine auxotrophs and require exogenous pyrimidines (Nørby, 1970; Falk, 1976). We have established a set ofrudimentary cell lines that are derived from embryos, homozygous for eitherr 1 orr 36. The enzymatic activities of the pyrimidine synthesizing enzymes were measured in the mutant lines. We have further investigated the nutritional requirements of the mutant cells in vitro by using a pyrimidine free culture medium. Ther 1 cell lines were found to express 3–7%dihydroorotase (DHOase) activity as compared to a wildtype cell line. Reducedaspartate transcarbamylase (ATCase) activity was measured in somer 1 cell lines whereas wildtypecarbamylphosphate synthetase (CPSase) activity is expressed in allr 1 cell lines. Ther 36 cell line expresses wildtype activity ofDHOase andCPSase. ATCase activity was found to be reduced to 10% of the wildtype activity. The mutant cell lines do not proliferate in pyrimidine free minimal medium and cell proliferation is obtained by the addition of crude RNA. Proliferation of ther 1 cells is restored by the supplementation of the minimal medium withdihydroorotate whereas proliferation of ther 36 cells is restored by supplementation with eitherdihydroorotate orcarbamylaspartate. The results demonstrate that therudimentary phenotypesr 1 andr 36 are expressed at the cellular level and that the two mutant cell types behave as cellular pyrimidine auxotrophs in vitro.
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  • 74
    ISSN: 1573-4927
    Keywords: sepiapterin synthase ; variegation ; purple ; Drosophila melanogaster ; pteridine eye pigments ; drosopterin
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A variegated position effect on the autonomous gene, purple, has been studied enzymologically in Drosophila melanogaster. Sepiapterin synthase, the enzyme system associated with pr +, was examined for activity in different developmental stages of the fly. The results indicate that T(Y:2) pr c5, cn/prc4 cn flies (flies in which pr + has been translocated and which exhibit variegation) have a reduced amount of enzyme activity as compared with both Oregon-R and pr 1 flies. This reduction in activity was not found in larval stages, which suggests that the inactivation process probably occurs in late larval or early pupal stages. The phenotype of the variegated adult has white eyes with red-colored spots and patches where drosopterins occur. The phenotype of the fly carrying the translocation is modified by the presence of additional Y chromosomes. This extends the observation from other systems that extra heterochromatin acts to suppress the variegated position effect. The advantages of studying the variegation by measuring enzyme activity, as well as the phenotypic expression, are several; for example, the developmental time at which variegation occurs may be estimated even though drosopterin synthesis is not occurring.
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  • 75
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    Biochemical genetics 17 (1979), S. 1131-1144 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; enzyme polymorphism ; G6PD ; 6PGD ; enzyme activity
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The electrophoretic variants of G6PD and 6PGD isolated from the Bogota Drosophila melanogaster population were characterized developmentally and biochemically. Changes in in vitro enzyme activity during development were comparable to those found for other dehydrogenases: an increase in the larval and adult stage and a decrease in the pupal stage. During the whole life cycle the “S” enzyme of both loci showed a higher activity than the “F” enzyme. MgCl2 had a stimulating effect on the activity of both enzymes whereas their heat stability was decreased. The allozymes of 6PGD had different Vmax's but were comparable with respect to Km values, pH optimum, and stability at 45 C. the allozymes of G6PD showed different Vmax's and differed in stability at 35 C, but had similar Km values and pH optima. As the difference in stability was probably due to differences in molecular structure of the allozymes, the differences in activity found at high pH and high MgCl2 concentration were most probably due to this difference in stability.
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  • 76
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    Biochemical genetics 17 (1979), S. 1-22 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; esterase 6 ; allozymes ; biochemical properties
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Biochemical properties of esterase 6 in Drosophila melanogaster were investigated using partially purified preparations from three genotypes, 1/1, 1/2, and 2/2. The molecular weight of the enzyme is estimated to be about 90,000, and treatment with sodium dodecylsulfate cleaves the enzyme into four units with a molecular weight of about 22,000. The activity toward 28 naturally occurring esters was assayed and shown to vary considerably with substrate, the 1/1 preparation having in general higher activity than 1/2 and 2/2, which were very similar. Heat sensitivity, the effect of metal ions, and the effects of the presence or absence of an end product were also studied. The differences demonstrated between allozymes would allow considerable scope, under appropriate conditions, for differential selection to operate between genotypes.
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  • 77
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; phosphoglucomutase ; polymorphism ; enzyme kinetics
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Phosphoglucomutase (PGM) of adult stage in Drosophila melanogaster has been characterized by gel filtration, ion-exchange chromatography, and isoelectric focusing. The two common electrophoretic variants, PGMA and PGMB, differ with respect to their kinetic and stability parameters. PGMA is more thermostable than PGMB but shows the same pH optimum, equal dependence on Mg2+, and identical molecular weight. There is no significant kinetic difference between the two allozymes at the optimum pH value, but at pH 6.0 the K m value for glucose-1,6-diphosphate of PGMB is significantly higher than that of PGMA. This difference might explain the observed selective advantage of the Pgm A allele in population studies.
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  • 78
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    Biochemical genetics 17 (1979), S. 97-104 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; form II RNA polymerase initiation sites ; chromomeres
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The in vitro incorporation of γ-32P-labeled nucleoside triphosphates into RNA by Drosophila melanogaster form II RNA polymerase from template sites which afford protection from the initiation inhibitor, polyriboinosinic acid (poly [I]), is used as a method for enumerating a specific class of transcription initiation sites on D. melanogaster DNA. Such sites number about 4000 per haploid genome for D. melanogaster. This value is in good agreement with the number of functional genetic units in the D. melanogaster genome as determined by classical cytogenetics.
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  • 79
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; Malpighian tubules ; purine transport ; eye color mutants ; riboflavin
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Uptakes of guanine into Malpighian tubules of wild-type Drosophila and the eye color mutants white (w), brown (bw), and pink-peach (p p) have been compared. Tubules for each of these mutants are unable to concentrate guanine intracellularly. The transport of xanthine and riboflavin is also deficient in w tubules. The transport of guanosine, adenine, hypoxanthine, and guanosine monophosphate is similar in wild-type and white Malpighian tubules. These data and other information about these mutants make it likely that these pteridine-deficient eye color mutants do not produce pigments because of the inability to transport a pteridine precursor. This view supports the hypothesis that mutants which lack both pteridine and ommochromes do so because precursors to both classes of pigments share a common transport system.
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  • 80
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    Biochemical genetics 17 (1979), S. 149-158 
    ISSN: 1573-4927
    Keywords: xanthommatin synthesis ; scarlet mutants ; Drosophila melanogaster ; temperature-sensitive mutants
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Six new EMS-induced scarlet mutants were selected. Four of these were partially pigmented, with xanthommatin levels ranging from 12% to 45% of normal. In one (st 754ts), pigment production was temperature sensitive; the level of xanthommatin changed from less than 10% of normal at 29 C to more than 70% at 18 C. In all of the new mutants tested, the level of early pupal 3-hydroxykynurenine was as low as low as that in st 1. Thus reduced larval accumulation of this metabolite also appears to be a characteristic feature of scarlet mutants. Temperature-pulse and temperature-shift experiments were carried out with st 754ts to determine the temperature-sensitive period for the scarlet gene during development. The major sensitive period commenced prior to the onset of pigmentation and was over before adult emergence. Thus the initiation of xanthommatin synthesis is not brought about by the activation of the scarlet gene. In similar experiments carried out with a temperature-sensitive white mutant (w bl), a similar temperature-sensitive period was obtained.
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  • 81
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; biopterin synthesis ; oxidation of dihydropterins
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An enzyme which has been named “biopterin synthase” has been discovered in Drosophila melanogaster. This enzyme, which has been purified 200-fold from extracts of Drosophila, catalyzes the conversion of sepiapterin to dihydrobiopterin, or oxidized sepiapterin to biopterin. The K m values for the two substrates are 63 µm for sepiapterin and 10 µm for oxidized sepiapterin. NADPH is required in this enzymatic reaction. An analysis of enzyme activity during development in Drosophila indicates a correlation between enzyme activity and biopterin content at various development stages. Another enzyme, called “dihydropterin oxidase,” was also discovered and partially purified. This enzyme catalyzes the oxidation of dihydropterin compounds to the corresponding pterin compounds. For example, sepiapterin (a dihydropterin) is oxidized to oxidized sepiapterin in the presence of this enzyme. The only dihydropterin that has been tested that is not a substrate for this enzyme is dihydroneopterin triphosphate, the compound thought to be a precursor for all naturally occurring pterins and dihydropterins. Since the action of dihydropterin oxidase is reduced significantly when the concentration of oxygen is very low, it is likely that this enzyme uses molecular oxygen as the oxidizing agent during the oxidation of dihydropterins. Neither NAD+ or NADP+ is required. In the presence of the two enzymes dihydropterin oxidase and biopterin synthase, sepiapterin is converted to biopterin. However, in the presence of biopterin synthase alone, sepiapterin is converted to dihydrobiopterin.
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  • 82
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    Theoretical and applied genetics 55 (1979), S. 231-238 
    ISSN: 1432-2242
    Keywords: Drosophila melanogaster ; Scute locus ; Maps ; Operon-like model
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    Topics: Biology
    Notes: Summary The functional expression of 12 scute alleles in homozygotes and compounds of Drosophila melanogaster at 14°, 22°, 30°C is analysed. Based on the data obtained, linear maps for bristles and mutations are built. The basic features of the maps, clustering and polarity, are invariable with respect to temperature, scute gene dosage and cross direction. In addition local dominance of the norm over bristle reduction was produced by the scute mutation; different types of complementation reactions were established for each bristle. The gene scute is treated as an operon-like system, composed of 3–4 cistrons with each controlling the formation of bristles on a particular region of the fly's body. This model argues well with the structure of maps constructed and implies a post-translational level of initial events of bristle-formation process.
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  • 83
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    Behavior genetics 9 (1979), S. 123-128 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; phototaxis ; X chromosome
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    Topics: Biology , Psychology
    Notes: Abstract Strains ofDrosophila melanogaster differ in their phototactic responses to red light (654 nm). Genes located on all three major chromosomes are involved in influencing the response, but the X chromosome and third chromosome account for most of the variation in phototaxis.
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  • 84
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    Behavior genetics 9 (1979), S. 129-134 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; D. simulans ; larval feeding behavior ; egg-to-adult viability ; isofemale line
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    Topics: Biology , Psychology
    Notes: Abstract Larval feeding behavior of isofemale lines of the sibling speciesDrosophila melanogaster andD. simulans was investigated. This behavior was measured as the number of cephalopharyngeal retractions of individual larvae per 30 sec period (CPR score) in different generations (G0, G1, and G14). In addition, egg-to-adult viability was estimated in each isofemale line. The results were as follows: (1) In either species, there was variation of CPR score among individuals and among isofemale lines. Although no differences of CPR score were found among experimental groups (generations) and between species, there was a significant difference among isofemale lines. (2) The behavioral trait was stable through generations in each isofemale line. (3) This behavior was correlated with egg-to-adult viability, showing that it is important for the development of the fly.
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  • 85
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    Behavior genetics 9 (1979), S. 209-217 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; D. simulans ; D. pseudoobscura ; pupation height ; geotaxis ; species differences ; selection for pupation height
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    Topics: Biology , Psychology
    Notes: Abstract Pupation heights of various natural and laboratory populations ofDrosophila melanogaster, D. simulans, andD. pseudoobscura were observed in the laboratory under conditions of continuous darkness or continuous light. Generally higher mean pupation heights were observed under conditions of darkness.D. melanogaster tended to pupate higher than theD. pseudoobscura populations, andD. pseudoobscura tended to pupate higher thanD. simulans. The order of these species differences was similar whether pupation was measured in light or in darkness. Results of selection for pupation height inD. melanogaster suggest the presence of genetic variation for this character. The possibility that a relationship exists between adult and larval behaviors was explored by measuring the pupation heights of larvae from strains selected for geotactic behavior as adults, and also by measuring geotaxis of adults from strains selected for pupation height.
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  • 86
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    Behavior genetics 9 (1979), S. 257-275 
    ISSN: 1573-3297
    Keywords: sexual behavior ; Drosophila melanogaster ; genetic mosaics ; ontogeny of behavior ; wing vibration
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    Topics: Biology , Psychology
    Notes: Abstract The sex appeal of aDrosophila melanogaster female is defined here as the stimulus (or set of stimuli) which induces wing vibration in courting males. A quantitative measure of sex appeal is the cumulative duration of wing vibration induced by a given female averaged over several consecutive test intervals using different standardized male testers (sex appeal parameter, SAP). By use of SAP, both males and females are found to have the same amount of sex appeal on the first day after eclosion. However, males rapidly lose it by the next day, so that mature males become distinct from females. We report the ontogeny of the male's response to sex appeal. By the SAP method, we also demonstrate that the male's response is dependent on his previous encounter with females. The sex appeal of 287 gynandromorphs was examined in order to localize the sex appeal focus by means of blastoderm fate mapping. Most mosaic flies were classified as either positive (femalelike, with high SAPs) or negative (malelike, with SAPs of zero). Sixteen percent of the gynandromorphs had intermediate levels of SAP, inducing only short vibrations, a response which males rarely give to normal females. Assuming that the gynanders with such intermediate sex appeal must have both female and male foci, distances to the foci from external landmarks were calculated. The center of the focus seems to be an internal structure mapping to the ventroposterior region of the blastoderm fate map, close to the primordia of the anterior sternites. The focus might include a large mesodermal area, but only part of it must have a female genotype for the sex appeal to be expressed. A possible involvement of the fat bodies in production of the sex appeal stimulus is discussed in relation to these findings. Consistent with this conclusion is the fact that females whose abdomens were amputated still retain enough sex appeal to induce male wing vibrations.
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  • 87
    ISSN: 1573-3297
    Keywords: aristal morphology ; Drosophila melanogaster ; artificial selection ; geotaxis ; mating behavior
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    Topics: Biology , Psychology
    Notes: Abstract The aristae ofDrosophila have been shown to play a role in mating behavior and geotaxis. Two populations ofD. melanogaster were selected for increased and decreased numbers of major aristal branches. Selection was successful and resulted in two lines differing by an average of six aristal branches. Hybridization analyses of selected lines revealed that genes influencing aristal branching are located on both the X chromosome and the autosomes. Polygenic control of aristal morphology is indicated by a gradual response to selection and low realized heritabilities. When selection was relaxed for 19 generations, the number of aristal branches did not revert to the number in the control line. Changes in aristal branching did not appear to have a consistent influence on geotaxis, although there was a tendency for flies with fewer aristal branches to be geonegative. Neither mating speed nor ethological isolation between the two populations was affected by selection. It is concluded that the number of aristal branches inDrosophila is a neutral trait (i.e., not subject to natural selection) under laboratory conditions. Correlations between aristal morphology and behavior found in other selection experiments by previous investigators were likely due to linkage disequilibria.
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  • 88
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    Behavior genetics 9 (1979), S. 407-412 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; oviposition site preference ; substrate temperature ; heritability
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    Topics: Biology , Psychology
    Notes: Abstract Drosophila melanogaster females from a multifemale stock (SC-1) showed strong oviposition site preference (OSP) in a continuous gradient of substrate temperatures (18–31°C). Flies reared at 25°C had an OSP ( $$\bar X$$ ±SE) of 25.2±0.2°C, whereas flies reared at 18°C had an OSP of 23.5±.2°C. Flies reared from egg to adult at one temperature and exposed as adults for 4 days to another temperature had OSPs intermediate between these extremes. This second 4-day exposure seemed to have a greater effect on OSP than the first rearing temperature. Selection experiments failed to produce significant change in mean OSP in eight generations, indicating a low heritability of temperature OSP in this stock.
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  • 89
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    Behavior genetics 9 (1979), S. 425-429 
    ISSN: 1573-3297
    Keywords: random mating ; Drosophila pseudoobscura ; pheromones ; Drosophila melanogaster
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    Topics: Biology , Psychology
    Notes: Abstract Inbreeding, up to 12 generations of single-pair matings, did not cause significant deviation from random mating among two sets of strains inDrosophila pseudoobscura. This contrasts with reports that inbreedingD. melanogaster induces negative assortative mating among lines.
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    Behavior genetics 9 (1979), S. 543-553 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; divergent selection ; locomotor activity ; heritability
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    Topics: Biology , Psychology
    Notes: Abstract Selection for high and low locomotor activity has been applied in two base populations ofDrosophila melanogaster of distinct geographical origin. From each base population a high and a low line were selected, in which anesthesia was performed with ether. In addition, from one of the base populations a high line and a low line were selected under CO2 narcosis. Locomotor activity was measured in an apparatus consisting of rows of 20 tubes in a line. Heritabilitities in the base populations determined in progeny tests were approximately 10%. Divergent directional selection was successful with realized heritabilities of similar value.
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  • 91
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; locomotor activity ; mating preference ; sexual isolation ; fertility ; selected lines
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    Topics: Biology , Psychology
    Notes: Abstract Tests for reproductive isolation between lines selected for locomotor activity were performed. Three sets of selection lines were used, each consisting of lines selected for low and high locomotor activity from the same base population. Females preferred high-activity males in almost every case. However, in one of the sets temporary sexual isolation was found between flies of the high and low lines. This was accompanied in the low-activity females with a higher fertility when they were mated with their own males. After further selection the partial isolation disappeared.
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  • 92
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    Behavior genetics 9 (1979), S. 563-570 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; locomotor activity ; genetic analysis ; X chromosome ; selected lines
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    Topics: Biology , Psychology
    Notes: Abstract Divergent directional selection produced three pairs of lines each consisting of a line with high and a line with low locomotor activity. Reciprocal crosses between the high and low lines of one of these pairs showed that a considerable part of the activity differences was contributed by differences between the X chromosomes. This was confirmed by a substitution of the three large chromosomes, between the low and the high lines. The two large autosomal chromosomes had only minor effects. Interactions between chromosomes were sometimes significant. Low-activity alleles tended to be dominant over alleles for high activity.
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    Development genes and evolution 184 (1978), S. 41-56 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Female germ line ; Mosaics ; Stem cell divisions ; Metafemale ; Sterility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Our report presents an analysis of the development and dynamics of the female germ line inDrosophila. Females were produced that were mosaic either for attached-X chromosomes $$(\widehat{XX})$$ and a ring-X (triplo-X-diplo-X), or for $$\widehat{XX}$$ and a marked Y-chromosome $$(\widehat{XX}/Y - \widehat{XX}/O)$$ . The germ-line and genitalia of these females were analysed by direct microscopic observation or by examination of the progeny. Eggs derived from triplo-X germ cells were hardly capable of supporting development, with most of the zygotes dying during embryonic development. The analysis of the germ line was therefore carried out mainly by direct observation of histochemically stained developing oocytes in the ovaries of mosaic females. The total germ cell population of both ovaries of a female was mosaic in 22–29% of the tested animals. From this frequency of mosaicism we estimated the number of functional primordial germ cells to be betwen 3 and 6 cells at the blastoderm stage. At this stage the cell lineages for the left and right ovary are not yet separated. The germ cell population of individual ovarioles was frequently mosaic which shows that the few stem cells in an ovariole are recruited as a group and are not clonal descendants of a single ancestor cell per ovariole. An analysis of the sequential pattern of oocyte-nurse cell cysts in mosaic ovarioles revealed that neighbouring cysts tend to be of the same genotype. This suggests that the stem cells of the adult ovaries preferentially divide in bursts, one of them giving rise to two, three and sometimes even more cystocytes in a row. In addition, the foci for lethality and sterility of the triplo-X condition were determined. Non-mosaic triplo-X females (metafemales) are hardly viable and invariably sterile. Using our mosaics, the focus forlethality could be mapped to a region very near the ventral prothoracic discs. The focus forsterility resides in the genitalia, since flies with triplo-X genitalia never laid any eggs, regardless of the genotype of their ovaries.
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  • 94
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; GTP cyclohydrolase ; development ; pteridine biosynthesis ; mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The reaction catalyzed by GTP cyclohydrolase is the first unique step of pteridine biosynthesis in Drosophila melanogaster and is therefore likely to be an important control point. GTP cyclohydrolase activity varies during development, showing two distinct peaks of activity—one at pupariation and a much larger peak at emergence. Most of the early pupal enzyme is located in the body region, whereas in late pupal and early adult life most of the activity is found in the head. Mixing experiments indicate that developmental changes in activity are not due to changes in the level of a direct effector of GTP cyclohydrolase. The mutants raspberry and prune show an increased GTP cyclohydrolase activity at pupariation relative to wild type, but a decreased enzyme activity at emergence. The changes in GTP cyclohydrolase activity are reflected in changes in pteridine levels in these mutants. Several lines of evidence suggest that neither locus is the structural gene for GTP cyclohydrolase. The raspberry and prune gene products may play a specific role in regulating GTP cyclohydrolase activity during development.
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    Biochemical genetics 16 (1978), S. 1113-1134 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; isozymes ; position effect ; segmental aneuploidy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A deoxyribonuclease, called DNase-1, that is active at acid pH in the presence of EDTA has been studied in Drosophila melanogaster. The locus for the enzyme maps genetically to 61.8 on the right arm of the third chromosome. Cytogenetically, DNase-1 has been localized to within five to ten bands between 90C-2 and 90E. This analysis utilizes both electrophoretic variants and the Y-autosome translocations of Lindsley et al. (1972). DNase-1 is present in all stages of the life cycle, and the paternal genome actively contributes DNase-1 to the embryo between 0 and 1 hr after fertilization.
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    Biochemical genetics 16 (1978), S. 159-170 
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; allozyme properties and amounts ; Drosophila melanogaster
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Among strains of Drosophila melanogaster each derived from a single fertilized female taken from natural populations, there is variation in both alcohol dehydrogenase (ADH) activity and the amount of ADH protein. The correlation between ADH activity and number of molecules over all strains examined is 0.87 or 0.96 in late third instar larvae depending on whether the substrate is 2-propanol or ethanol. With respect to the two common electrophoretic allozymic forms, F and S, segregating in these populations, the FF strains on the whole have higher ADH activities and numbers of ADH molecules than the SS strains. Over all strains examined, enzyme extracts from FF strains have a mean catalytic efficiency per enzyme molecule higher than that of enzyme extracts from SS strains when ethanol is the substrate, and much higher when 2-propanol is the substrate. One FF strain had an ADH activity/ADH protein ratio characteristic of SS strains.
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  • 97
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    Keywords: Drosophila melanogaster ; alcohol tolerance ; alcohol utilization ; alcohol dehydrogenase ; aldehyde oxidase ; allozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Alcohol dehydrogenase is necessary for ethanol detoxification and metabolic utilization. It has been generally assumed that aldehyde oxidase (AO) produced by the Aldox locus (3–56.7) is necessary for a further transformation of acetaldehyde into acetate. We find that various mutant strains (ma-l or Aldox n) which do not produce an active enzyme show about the same tolerance to alcohol as do wild strains. This physiological paradox is probably to be explained by the discovery of another locus (not localized) which produced a small amount of AO in all tested strains. The adaptive significance of the genetically polymorphic Aldox locus is probably to be looked for in physiological pathways other than ethanol metabolism.
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  • 98
    ISSN: 1573-4927
    Keywords: nonelectrophoretic structural variability ; Drosophila melanogaster ; phosphoglucomutase ; genetic polymorphism ; heat denaturation study
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A simple procedure is described to detect genetic heterogeneity within electrophoretic classes at a locus in Drosophila, based on electrophoresis and heat denaturation studies. Temperature-resistant (tr) and temperature-sensitive (ts) isoelectrophoretic alleles at the phosphoglucomutase locus (Pgm) are present at polymorphic frequencies in natural and in laboratory populations of Drosophila melanogaster.
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    Biochemical genetics 16 (1978), S. 333-342 
    ISSN: 1573-4927
    Keywords: β-hydroxy acid dehydrogenase ; chromosome ; dosage compensation ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A mutant Had nl was induced in Drosophila melanogaster and found to be deficient in β-hydroxy acid dehydrogenase. This mutation was utilized to study the genetics and physiological expression of Had +. Had+ was mapped to the X chromosome at 54.4 and seems to be the structural gene for the enzyme. Enzyme activity in male and female flies indicates that the gene shows both dosage compensation independent from dose effect and differential activity during ontogeny. Electrophoretic mobility data indicate that the enzyme is a dimer which forms by random association of subunits. The fact that the mutant shows no detrimental effect implies that the enzyme is dispensable, at least under laboratory conditions. The biological and technical implications of this gene-enzyme system are discussed.
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  • 100
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; 6-phosphogluconate dehydrogenase ; Pgd n lethal alleles ; rescue by dietary supplements ; hexose monophosphate shunt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The genetic rescue of Pgd n lethal alleles, accomplished by combining them with mutations lacking glucose-6-phosphate dehydrogenase activity, has led to the hypothesis that Pgd n lethality may be due to the accumulation of 6-phosphogluconate. In this article we report the rescue of Pgd n /Y males by dietary supplements (fructose and linolenate) designed to minimize 6-phosphogluconate production.
    Type of Medium: Electronic Resource
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