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  • Drosophila melanogaster  (266)
  • Springer  (266)
  • 2015-2019
  • 1985-1989  (128)
  • 1980-1984  (71)
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  • 1
    ISSN: 1572-8889
    Keywords: larval behavior ; compound autosomes ; genetic mapping ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic control of the rover/sitter behavioral polymorphism in Drosophila melanogasterlarvae was localized to the left arm of chromosome 2.Ten independent left and right compound second chromosomes were generated in isogenic rover and sitter strains by gamma irradiation and substituted into 25 different lines. Comparisons were made between lines to determine the chromosome arm contributions to rover/sitter phenotype expression.
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  • 2
    ISSN: 1572-8889
    Keywords: Drosophila melanogaster ; larval foraging behavior ; genetics ; development ; plasticity ; patch quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genetically based rover/sitter behavioral difference in Drosophila melanogasterlarval foraging is expressed throughout most of the larval instars when larvae forage on food patches of differing food quality. The amount of locomotor behavior decreases when third-instar larvae of both rover and sitter strains are starved just prior to the behavioral test. Such strain differences in locomotor behavior are maintained despite the starvation-induced decrease in locomotion found in both strains. Measurements of larval body length and width, taken at 24, 48, 72, and 96 h posthatching, reveal that rover and sitter larval growth rates do not differ. The finding that rover/sitter differences are expressed in a variety of environments and throughout the majority of the larval instars should aid in attempts to uncover selection pressures which may differentially affect the two morphs in environmentally heterogeneous natural populations.
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  • 3
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    Journal of insect behavior 2 (1989), S. 575-588 
    ISSN: 1572-8889
    Keywords: aging ; behavior ; central nervous system ; Drosophila melanogaster ; Diptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have monitored the ontogeny of several behaviors performed by young Drosophila melanogasteradults. Very young flies are less active than older flies and are less responsive to gravity, light, an odorant, and sucrose applied to their tarsi. In addition, very young males do not consume sucrose or perform any courtship behaviors in response to virgin females, which provide chemical and visual stimuli to courting males. The rate at which flies become maximally competent to respond to stimuli is a function of the behavior. Sensory and motor deficits are not solely responsible for young flies' inability to respond to the stimuli, which suggests that the central nervous system continues to develop after eclosion.
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  • 4
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    Journal of insect behavior 2 (1989), S. 829-834 
    ISSN: 1572-8889
    Keywords: Drosophila melanogaster ; larval behavior ; microhabitat ; heritability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 5
    ISSN: 1572-8889
    Keywords: Drosophila melanogaster ; searching behavior ; foraging ; genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Drosophila melanogasteradults were employed in single resource patches of varying density and size and in a multiple-patch array to determine the degree to which resource dispersion influences searching success. Individuals from rover and sitter selected lines, with extreme genotypes for local search duration, are not as successful as control-line (wild-type) flies in locating sucrose drops in single patches varying in size and density. The number of new drops located differed significantly between fly lines in all patch types, except in a high-density patch, and within each fly line over the different patch sizes and densities. The similarities in number of drops found by rovers and sitters in all patch types are not reflected in the time periods spent searching. In the multiple-patch array sitters never left the central patch, whereas most rovers and con-trol-line flies found additional patches. The proximate explanations for the success or failure of the three fly lines in different patch sizes and densities relate to the looping locomotor pattern characterizing local search in D. melanogaster.The reactivation of searching each time a drop is ingested or revisited keeps an individual in the immediate vicinity of the last encountered resource. Flies from the selected lines, each exhibiting extreme types of locomotor patterns, leave patches relatively unexploited because local search consists either of rapid, nearly linear movement away from a drop in rovers or of relatively long bouts of local search in sitters, which promotes revisiting rather than locating new drops. Control-line flies locate more drops than either rovers or sitters and in less time than sitters, suggesting that their intermediate phenotype for search behavior allows for more flexibility in searching in various patch sizes and resource densities. The results are discussed with reference to environmental and physiological factors that may modify searching behavior and, possibly, enhance the survival of individuals with extreme genotypes.
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  • 6
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    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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  • 7
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    Cellular and molecular life sciences 41 (1985), S. 1346-1347 
    ISSN: 1420-9071
    Keywords: Positional information ; temperature effects ; gradients ; campaniform sensillae ; wing veins ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The mutant hairy (h) increases the number of sensillae on theDrosophila wing. This allows us to quantify a gradient that determines the type of sense organ that forms along the third long vein. Temperature significantly shifts the positional responses to this underlying gradient.
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  • 8
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    Cellular and molecular life sciences 41 (1985), S. 745-746 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; salivary gland ; larval ; DNA replication ; DDT ; chromosomes ; polytene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The inhibitory effect of DDT on the initial stage of the DNA replication process in polytene chromosomes of larval salivary gland cells ofDrosophila melanogaster was investigated and possible mechanisms for the inhibition are discussed.
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  • 9
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    Cellular and molecular life sciences 42 (1986), S. 307-309 
    ISSN: 1420-9071
    Keywords: Ecdysteroid ; sterols ; Drosophila melanogaster ; ring gland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Brain-ring glands fromDrosophila larvae reared on a defined diet containing campesterol (24-methyl-cholesterol) as the major sterol, secreted-in addition to ecdysone-a compound identified previously as a 24-methyl analogue, 20-deoxy-makisterone A. Using ergosterol or cholesterol as the sterol component of the diet, only ecdysone was detectable in cultures of brain-ring glands.
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  • 10
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    Cellular and molecular life sciences 41 (1985), S. 946-948 
    ISSN: 1420-9071
    Keywords: Acetaldehyde oxydation ; alcohol dehydrogenase ; aldehyde dehydrogenase ; Drosophila melanogaster ; Drosophila simulans ; ethanol catabolism ; null-mutants for alcohol dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Aldehyde dehydrogenase (ALDH) activity is demonstrated in four strains ofD. melanogaster lacking active alcohol dehydrogenase (ADH-null mutants). In the four strains, ALDH activities are similar to those found in a wild strain. It is concluded that ADH-null flies are able to detoxify acetaldehyde. This finding is discussed in relation with the dual function of ADH proposed recently.
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  • 11
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    Cellular and molecular life sciences 42 (1986), S. 1048-1050 
    ISSN: 1420-9071
    Keywords: Allozyme polymorphism ; linkage disequilibrium ; wine cellar and field populations ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Over three years, theAdh and α-Gpdh loci have been studied in two cellar populations ofDrosophila melanogaster and in two field populations which were each near to one of the cellars. Analyses of gene frequencies indicate that the divergence among subpopulations is greater in theAdh locus than in the α-Gpdh locus. Selection for or againstAdh S allele acting on theIn(2L)t inversion influences of the α-Gpdh alleles. This phenomenon may contribute to explain the maintenance of theAdh and α-Gpdh polymorphism and of theIn(2L)t inversion.
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  • 12
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    Cellular and molecular life sciences 41 (1985), S. 1078-1079 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; intercalating mutagens ; crossing-over ; clastogenic activity ; recombination induction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to evaluate the effect of several intercalating compounds on crossing-over inDrosophila melanogaster females, acridine orange, acriflavine, chloroquine, ethidium bromide and quinacrine were fed separately to larvae ofy ct f/+++ genotype. Our results show that acridine orange, acriflavine and ethidium bromide increase significantly the recombination frequency at thect-f region and support the view that, for intercalating agents, there is a relationship between clastogenic activity and female recombination induction.
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  • 13
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    Cellular and molecular life sciences 44 (1988), S. 618-621 
    ISSN: 1420-9071
    Keywords: Sensitive period ; phenocopy ; yellow ; survivorship ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Yellow phenocopies ofDrosophila melanogaster were produced by raising larvae on α-DMT contaminated media. Using a survivorship test, the sensitive period for phenocopy induction was found to occur during the third larval instar of development, with increased survivorship at 1% α-DMT compared with lower concentrations. It was also found that treatment with α-DMT significantly slowed development. These findings are related to the relevant morphological and behavioral developmental pathways and to phenocopy induction.
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  • 14
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    Entomologia experimentalis et applicata 48 (1988), S. 61-67 
    ISSN: 1570-7458
    Keywords: cytoplasmic incompatibility ; Drosophila melanogaster ; maternal inheritance ; reproductive isolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les souches de D. melanogaster récoltées à Melbourne (37°S) et Townsville (19°S) sur la côte Est de l'Australie montrent une incompatibilité partielle lorsque les femelles Melbourne sont accouplées aux mâles Townsville. Une telle incompatibilité n'est décelée, ni dans les croisements intrapopulations, ni dans le croisement réciproque. Le taux d'éclosion des oeufs est réduit d'environ 30% dans le croisement incompatible, mais la viabilité des larves n'est pas modifiée. Les éléments, mâle et femelle, de ce système d'incompatibilité sont hérités maternellement pendant 3 générations de croisements en retour. La compatibilité peut être intégralement rétablie en cultivant pendant une génération la souche Townsville avec un régime contenant de la tétracycline, et partiellement rétablie en utilisant des mâles âgés de 2 semaines.
    Notes: Abstract Drosophila melanogaster (Meigen) females from stocks collected at Melbourne (latitude 37°S) show partial incompatibility when mated with males from stocks collected at Townsville (latitude 19°S) on the east coast of Australia. The reciprocal cross is compatible. Eggs have reduced hatchability in the incompatible cross. The incompatibility is maternally inherited over three generations. Compatibility can be restored by culturing Townsville flies on medium with tetracycline for one generation and by using 2-week-old Townsville males.
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  • 15
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    Entomologia experimentalis et applicata 52 (1989), S. 159-166 
    ISSN: 1570-7458
    Keywords: Sexual isolation ; sexual maturation ; Drosophila melanogaster ; Drosophila simulans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des lignées isofemelles de D. simulans ont été examinées pour déterminer l'âge de la maturité sexuelle des mâles avec des femelles conspécifiques et pour établir la fréquence de l'hybridation avec des femelles de D. melanogaster. Les mâles ont commencé à être sexuellement mûrs le premier jour après l'émergence, mais leur aptitude à la copulation a augmenté lentement pendant le jour suivant. Les estimations, tant de l'âge du début de la maturation sexuelle que de l'âge du passage de mâle immature à mâle sexuellement mûr dépendaient étroitement des génotypes des femelles utilisées dans les expériences. Il n'y avait pas de différences nettes entre les lignées de mâles. Par contre, des différences dans les fréquences d'hybridation avec les femelles de D. melanogaster ont été observées. De ces résultats, on peut conclure que les différences dans la réussite des hybridations des lignées de mâles de D. simulans n'étaient pas dues à la vitesse de maturation sexuelle des mâles.
    Notes: Abstract Isofemale lines of D. simulans were examined to determine the age of sexual maturity of males with conspecific females, and for the frequency of hybridization with D. melanogaster females. Males started to mature sexually on the first day after eclosion but their ability to mate slowly increased during the following day. The estimates of both the age sexual maturation started and the switch from immature to mature males were strongly dependent on the female genotypes used in the tests. No clear differences in speed of maturation were apparent between male lines. In contrast, differences in frequency of hybridization with D. melanogaster females did occur. From the above results it is concluded that the differential hybridization success of male D. simulans lines is not related to the speed at which males mature sexually.
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  • 16
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    Entomologia experimentalis et applicata 42 (1986), S. 145-149 
    ISSN: 1570-7458
    Keywords: Drosophila melanogaster ; polymorphisme électrophorétique ; populations naturelles françaises ; temps ; Drosophila melanogaster ; enzymatic polymorphism ; French natural populations ; time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Temporal patterns of allozyme variation over time have been examined for five polymorphic enzyme loci in 12 french natural populations of Drosophila melanogaster. Taken in their totality, the data show only slight changes in the genetical structure of these populations between years. The good viability of the imagoe at low temperatures and the occurrence of winter immediately after the demographic burst of the species in France involve that the population sizes during winter are probably sufficient to eliminate the genetic drift. Therefore, the stability in the genetical composition from one autumn to another could be explained by the way that the populations analyzed are panmictic.
    Notes: Abstract L'évolution dans le temps du polymorphisme de 5 locus enzymatiques a été suivie pour 12 populations naturelles françaises de Drosophila melanogaster. La structure génétique de ces populations ne varie pas, ou peu, d'un automne à l'autre. La bonne résistance au froid des imagos et le fait que la période hivernale suive celle de l'explosion démographique de l'espèce en France, indiquent que les populations analysées ne doivent pas subir d'importantes réductions de leurs effectifs durant l'hiver, susceptibles d'entraîner une forte dérive génétique. Dans ces conditions, le maintien de la même structure d'une année à l'autre peut s'expliquer par le fait que les populations sont panmictiques.
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  • 17
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    Journal of molecular evolution 27 (1988), S. 142-146 
    ISSN: 1432-1432
    Keywords: Drosophila melanogaster ; Adh ; Thermostable allele ; DNA sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleotide sequence of theFast-Chateau Douglas isolate of the thermostable alcohol dehydrogenase allele is compared with the sequences of theSlow andFast alleles ofDrosophila melanogaster. Conceptual translation of theFChD sequence indicates that the thermostable polypeptide has the diagnostic FAST amino acid replacement at residue 192 and an additional replacement of serine for proline at residue 214. This suggests aFast origin for the thermostableAdh allele. However, some of the biochemical properties of the FCHD protein resemble those of the SLOW rather than the FAST polypeptides. The serine for proline replacement confers upon the thermostable polypeptide substrate specificities and some kinetic parameters similar to the SLOW protein. The same replacement substitution within the third coding exon also appears to alter the ADH protein concentration to a level similar to the SLOW polypeptide and the probable effect is at the level of mRNA concentration. The low level of nucleotide sequence variation, other than that leading to the amino acid substitution, suggests a recent origin for the thermostable allele. The time since divergence of theFChD sequence fromFast is estimated to be approximately 260,000–470,000 years.
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  • 18
    ISSN: 1432-1432
    Keywords: Duplications ; Complementation ; Drosophila melanogaster ; Maroon-like ; Rosy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gene duplications must play an important role in the evolutionary development of living organisms. Presented here is a general scheme that uses complementary alleles to isolate gene duplications in diploid organisms. The technique was used inDrosophila melanogaster to assess the rate of spontaneous gene duplication at two loci, maroon-like and rosy. The results indicate (1) that the rate of duplication of the maroon-like locus is on the order of 2.7×10−6; (2) that the rate of duplication of the rosy locus is approximately 1.7×10−4; and (3) that duplication occurs in males, suggesting that there may actually be two modes of gene duplication inDrosophila melanogaster.
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  • 19
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    Development genes and evolution 182 (1977), S. 69-74 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Male foreleg disk ; Capacity of transdetermination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the male foreleg disk ofDrosophila melanogaster the cells capable of transdetermination are clustered in a specific region within the upper half of the disk. Cells outside this region cannot transdetermine under any of the experimental conditions thus far applied. Transdetermination occurs when cells capable of transdetermination are stimulated to a certain extent of additional proliferation. This can be achieved either by exposing these cells at a wound surface of an intact fragment, or by dissociation.
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  • 20
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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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  • 21
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    Development genes and evolution 191 (1982), S. 257-263 
    ISSN: 1432-041X
    Keywords: Juvenile hormone ; Precocene ; Drosophila melanogaster ; Oocyte degeneration
    Source: Springer Online Journal Archives 1860-2000
    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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  • 22
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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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  • 23
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    Development genes and evolution 194 (1985), S. 236-246 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; engrailed ; Selector gene ; Genetic complementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In 1975, Morata and Lawrence proposed that theengrailed (en) locus was a selector gene that controlled the different pathways of development followed by anterior and posterior compartments. This hypothesis assumed that the phenotype ofen 1 flies results from partial inactivity of theen + product. However, the mutant phenotype ofen 1/DF(2R)en − is weaker thanen 1/en 1. This implies that the partial P→A transformation ofen 1 does not result primarily from reduction inen + activity. Heterozygotes betweenl(2) en alleles andDf(2R)en − deletions express a similar phenotype of fused embryonic segments to that described by Nüsslein-Volhard and Wieschaus, and also by Kornberg, forl(2) en homozygoes. By this criterion, the lethal phenotype results from partial or complete lack ofen _ activity. Despite this, the1(2) en alleles give only a weak P→A transformation, whether recovered as embryonic lethals or by failure to complementen 1. They appear to define only one locus and, with the exception ofen 1, the available genetic date suggest that the complementation pattern at this locus is simple. Thus, it is unlikely thatengrailed is the sole determinant of the A/P compartment separation. It might be one of a number of loci that affect the alternative pathways followed by anterior and posterior compartments.
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  • 24
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Imaginal discs ; Lethal mutants ; Homeosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ash-1 locus is in the proximal region of the left arm of the third chromosome of Drosophila melanogaster and the ash-2 locus is in the distal region of the right arm of the third chromosome. Mutations at either locus can cause homeotic transformations of the antenna to leg, proboscis to leg and/or antenna, dorsal prothorax to wing, first and third leg to second leg, haltere to wing, and genitalia to leg and/or antenna. Mutations at the ash-1 locus cause, in addition, transformations of the posterior wing and second leg to anterior wing and second leg, respectively. A similar spectrum of transformations is caused by mutations at yet another third chromosome locus, trithorax. One extraordinary aspect of mutations at all three of these loci is that they cause such a wide variety of transformations. For mutations at both of the loci that we have studied the expression of the homeotic phenotype is both disc-autonomous (as shown by injecting mutant discs into metamorphosing larvae) and cell autonomous (as shown by somatic recombination analysis). The original mutations which identified these two loci, although lethal, manifest variable expressivity and incomplete penetrance of the homeotic phenotype suggesting that they are hypomorphic. The phenotype of double mutants which were synthesized by combining different pairs of those original mutations manifest for two of the four pairs a greater degree of expressivity and slightly more penetrance of the homeotic transformations. This mutual enhancement suggests that the products of both loci interact in the same process. A third double mutant expresses a discless phenotype. Additional alleles have been recovered at both the ash-1 and the ash-2 loci. Some of these alleles as homozygotes or transheterozygotes express the wide range of transformations revealed first by double mutants. One of the alleles at the ash-1 locus when homozygous and several transheterozygous pairs can cause either the homeotic transformation of discs or the absence of those discs. The fact that these two defects, absence of specific discs and homeotic transformations of those same discs can be caused by mutations within a single gene suggests that the activity of the product of this gene is essential for normal imaginal disc cell proliferation. Loss of that activity leads to the absence of discs, whereas, reduction of that activity leads to homeotic transformations.
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  • 25
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    Development genes and evolution 196 (1987), S. 473-485 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Proliferation ; Neuroblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The pattern of neuroblast divisions was studied in thoracic and abdominal neuromeres of wild-type Drosophila melanogaster embryos stained with a monoclonal antibody directed against a chromatin-associated antigen. Since fixed material was used, our conclusions are based upon the statistical evaluation of a large number of accurately staged embryos, covering the stages between the formation of the cephalic furrow up to shortened germ band. Our observations point to a rather stereotypic pattern of proliferation, consisting of several parasynchronous cycles of division. The data suggest that all SI neuroblasts divide at least eight times, all SII neuroblasts six or seven times and all SIII neuroblasts at least five times. This conclusion is based on the mapping of mitotic neuroblasts and is supported by the progressive reduction of the neuroblast volume and by the results of cell countings performed on embryos of increasing age. No conclusive evidence was obtained concerning the fate of the neuroblasts after their last mitosis, i.e. it cannot be decided whether the neuroblasts degenerate or become incorporated as inconspicuous cells in the larval ventral cord. The duration of the cycles of division of the neuroblasts was found to be 40–50 min each, while in the case of ganglion mother cells about 100 min are required to complete one cell cycle.
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  • 26
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    Cellular and molecular life sciences 41 (1985), S. 1607-1609 
    ISSN: 1420-9071
    Keywords: Neuronal specificity ; sensory projections ; serial homology ; ectopic transplantation ; Drosophila melanogaster
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    Topics: Biology , Medicine
    Notes: Summary Owing to a new transplantation technique, we have been able to study the sensory projections of homologous and heterologous appendages grafted to the same abdominal site inD. melanogaster. Axons from homologous transplants exhibit similar terminal patterns, whereas those from heterologous transplants do not. It is suggested that ectopic sensory axons specifically recognized central areas and pathways occupied by axons from homologous appendages.
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    Cellular and molecular life sciences 41 (1985), S. 57-58 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; aldehyde dehydrogenase ; mitochondria
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    Topics: Biology , Medicine
    Notes: Summary Subcellular fractionation by differential centrifugation confirms the presence of aldehyde dehydrogenase inD. melanogaster. It is found principally in the heavy mitochondrial fraction.
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    Cellular and molecular life sciences 41 (1985), S. 127-129 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; second chromosome ; drastics ; genetic load ; population size
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    Topics: Biology , Medicine
    Notes: Summary The effect of 750 second chromosomes ofDrosophila melanogaster on viability was studied. 19.3% of them proved letal or semilethal (=drastics) in homozygous condition. Compared to data obtained in previous years at the same sampling site, a significant frequency decrease of drastics during the past decade could be observed. The dynamic processes taking place in the Korean wild populations ofD. melanogaster are discussed.
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    Cellular and molecular life sciences 41 (1985), S. 1474-1476 
    ISSN: 1420-9071
    Keywords: Mobile elements ; inbreeding ; in situ hybridization ; Drosophila melanogaster
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    Topics: Biology , Medicine
    Notes: Summary The location of the mobile element mdg-1 was determined by in situ hybridization in salivary gland chromosomes ofDrosophila melanogaster. The locations of mdg-1 are nonrandom and some ‘hot spots’ exist. Moreover, the spectra of mdg-1 locations vary with the viability values of the families from which the larvae originated. This suggests that particular frequency spectra are associated with lethality resulting from inbreeding.
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    Cellular and molecular life sciences 42 (1986), S. 1051-1053 
    ISSN: 1420-9071
    Keywords: Age-structured population ; age-related mating success ; assortative mating ; generation overlap ; Drosophila melanogaster
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    Topics: Biology , Medicine
    Notes: Summary A series of experiments on age-related mating success and productivity provides evidence for assortative mating among three out of four age-classes inD. melanogaster. The preferred mating does not always result in the highest productivity. Three age classes of males contribute to reproduction while only females of the youngest age-class are involved. The progeny size is more affected by the age of the females than that of males. It is assumed that these findings must have important implications for generation overlap in natural populations.
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    Cellular and molecular life sciences 45 (1989), S. 983-985 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; sterol metabolism ; phytosterols ; dealkylation ; desmosterol ; sitosterol ; radiolabeled sterols
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    Topics: Biology , Medicine
    Notes: Summary Drosophila melanogaster was unable to dealkylate and convert [14C]sitosterol to cholesterol and no evidence was found for conversion of [14C]desmosterol to cholesterol. Therefore,D. melanogaster is incapable of dealkylating and converting C28 and C29 phytosterols to cholesterol.
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    Development genes and evolution 183 (1977), S. 249-268 
    ISSN: 1432-041X
    Keywords: Pattern-formation ; Embryogenesis ; Maternal-effect mutants ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary The mutationbicaudal (Bull, 1966) causes embryos to develop a longitudinal mirror image duplication of the posteriormost abdominal segments, while head and thorax are missing. These embryos occur with varying frequencies among eggs laid by mutant females, irrespective of the paternal genotype. Recombination and deletion mapping indicate thatbicaudal (bic) is a recessive, hypomorphic, maternal-effect mutation mapping at a single locus on the second chromosome ofDrosophila melanogaster close tovg (67.0±0.1). The frequency of bicaudal embryos depends on the age of the mother, her genetic constitution and the temperature at which she is raised. Best producers are very young females hemizygous forbic (bic/Df(2)vg B ) at 28° C. Under these conditions 80% to 90% of the eggs which differentiate can show the bicaudal embryo phenotype. Upon ageing of the mother the frequency of bicaudal embryos declines rapidly, and most of the eggs develop the normal body pattern. Temperature shift experiments suggest a temperature-sensitive period at the onset of vitellogenesis. The mutation causes several types of abnormalities in the segment pattern of theDrosophila embryo, which are interpreted as various degrees of expression of the mutant character. The most frequent abnormal phenotype is the symmetrical bicaudal embryo with one to five abdominal segments duplicated. Less frequent are asymmetrical types, in which the smaller number of segments is always in the anterior reversed part. Other phenotypes are embryos with missing or rudimentary heads, and embryos with irregular gaps in the segment pattern. In bicaudal embryos, the pole cells, formed at the posterior pole of the egg prior to blastoderm formation, are not duplicated at the anterior. The significance of thebicaudal phenotypes for embryonic pattern-formation inDrosophila is discussed.
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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
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    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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    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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    Keywords: Salivary gland ; Protein synthesis ; Larval development ; Drosophila melanogaster
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    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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    Development genes and evolution 194 (1985), S. 217-223 
    ISSN: 1432-041X
    Keywords: Malic enzyme ; Distribution patterns ; Imaginal discs ; Drosophila melanogaster
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    Notes: Summary The spatial distribution patterns of malic enzyme-NADP+ (ME) inDrosophila melanogaster imaginal discs and other structures were demonstrated histochemically. Staining in the imaginal discs was limited to specific areas where intense reactions occurred primarily in differentiating structures. The eye-antennal disc possessed the most distinctive staining pattern. The ommatidial preclusters and clusters of the eye portion both stained, with heavier deposition in mature clusters. Staining in the preclusters closest to the morphogenetic furrow (MF) was obscured by a band of stained cells on either side of the MF that extends dorsoventrally across the disc. The ME low activity mutantMen NCl showed a dramatic reduction in staining of this band of cells but had no visible effect on eye morphogenesis. The larval optic nerve which traverses the entire length of the eye-antennal disc was a consistently stained feature. Two structures specifically stained in the leg discs. The most prominent was the chordotonal organ, while the second was a larval nerve extending the length of the disc. Limited staining was observed in the wing disc. No ME staining could be detected in the labial disc or haltere disc. Even though the genital discs did not stain for ME, the enzyme was induced sometime during the pupal stage since intense staining was noted in several adult internal genital disc derived structures. In general, ME staining in imaginal discs was associated with structures from the nervous system.
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  • 37
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    Keywords: Drosophila melanogaster ; Cell lines ; 20-Hydroxyecdysone ; Extracellular glycoproteins
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    Notes: Summary The S3 cell line of Drosophila exhibits numerous responses to the molting hormone 20-hydroxyecdysone, including mitotic arrest, cell aggregation and extensive changes in cell surface and extracellular glycoproteins. We have produced polyclonal antibodies to a major hormone induced extracellular glycoprotein to investigate the role of this molecule in cell aggregation. This glycoprotein with a molecular weight of 110 kD (P110) is found primarily in the culture medium of hormone-induced cells. Upon reduction, the electrophoretic mobility of P110 is decreased, indicating the presence of internal disulfide bonds. Results from treatment of medium proteins with a cross-linking reagent indicate that the molecule is part of a higher molecular weight oligomer (300–400 kD). Fab fragments of anti P110 effectively inhibit the reaggregation of hormone-treated S3 cells, while preimmune Fab fragments have no effect. On the basis of these results, we propose that the P110 glycoprotein complex in the medium of hormone-treated cells functions in hormone-dependent cell-cell adhesion.
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    Development genes and evolution 198 (1989), S. 34-38 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Dosage compensation ; Male-specific lethal mutations
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    Notes: Summary The male-specific lethal genes (msl) of D. melanogaster represent a set of genes whose functions are required for the specific X chromosome hypertranscription in males (dosage compensation). We have carried out the clonal analysis of one of those msl mutations: msl-3 b. Clones homozygous for msl-3 b are deleterious; this mutation presents cell autonomy and in the cases where msl clones appeared in sexually dimorphic regions (5th and 6th tergites) they do not show sexual transformation. Moreover, the lethal phase and the growth dynamics (measured by the protein content during larval growth) are the same for male larvae homozygous for one msl mutation (msl-1) or three msl mutations (msl-2 msl-1 mle), i.e. the msl mutations do not show additive effects. This paper considers the possible interactions between the msl genes that bring about dosage compensation.
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    Development genes and evolution 183 (1977), S. 165-169 
    ISSN: 1432-041X
    Keywords: Clones ; Nervous system ; Shibire ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Mitotic recombination was induced, by X-irradiation at the blastoderm stage, in flies heterozygous for one of the temperature-sensitive paralytic mutationsshibire andtp-2. The results show that these mutations can be used to detect the presence of clones in the central nervous system through the temperature-sensitive paralysis of individual legs. Mitotic recombination can also be used to examine the effects of these mutations in the peripheral nervous system; shibire is thus shown to affect the function of sensory neurons.
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    Development genes and evolution 180 (1976), S. 107-119 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Cell lines ; Isoenzymes
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    Notes: Summary Our previous isoenzyme investigation ofDrosophila melanogaster cell lines in vitro has been completed with twelve further enzyme systems. The “enzyme profiles” seem to be in good agreement with a previous hypothesis concerning the precise origin of these cell lines (probably from imaginal discs or nervous tissues). Our results have been summarized with reference to the biochemical genetic map ofDrosophila melanogaster in order to consider a possible functional organization of the genome.
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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
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    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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    Development genes and evolution 187 (1979), S. 167-177 
    ISSN: 1432-041X
    Keywords: Pyrimidine biosynthesis ; rudimentary mutants ; Drosophila melanogaster
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    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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    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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    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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    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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    Development genes and evolution 193 (1984), S. 133-138 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Compartment boundary ; Operculum seam
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    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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    Development genes and evolution 195 (1986), S. 338-343 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Imaginai discs ; Aldehyde oxidse ; Determination ; Field size
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    Notes: Summary The pattern of aldehyde oxidase (AO) activity was determined in wing discs of Drosophila melanogaster larvae homozygous for the mutants apt 73n, Beaded, and vestigial (vg) in order to determine if reduction in field size in the pouch could be related to alterations of the wild-type AO pattern, as suggested by the Kauffman (1978) hypothesis. The pattern in wild-type discs was resolved into six areas for comparison with mutant discs. vg discs developed at 25° C showed restriction of the pattern into a small area on the anterior side of the disc, and comparison of vg and wild-type prepupal wings allowed positive identification of the AO pattern elements which remained. AO patterns in vg wing discs grown at 27°, 29°, and 31° C were progressively more complete and similar to wild-type, reflecting the reduction in cell death in discs grown at higher temperatures. These results show that cell loss during the third instar in vg development at 25° C is responsible for the alteration of the AO pattern, rather than field size reduction, and that determination of the pattern must take place much earlier than the time of its first appearance during the third larval instar, and before cell death in vg discs begins. Thus mutants acting at earlier stages will be necessary for further tests of the Kauffman hypothesis.
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    Development genes and evolution 195 (1986), S. 318-322 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Operculum ; Bithorax complex ; Determination
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    Notes: Summary We have studied the course of the operculum line in the larval hypoderm of several bithorax complex mutants of Drosophila melanogaster. The bifurcation of the line, a characteristic of the first abdominal segment in wild-type (A1), can also appear in the metathoracic (T3) and other abdominal segments (A2, A3) depending on mutations within the bithorax complex. Therefore, we concluded that the course of the operculum line and thus the shape of the operculum is not determined by a suprasegmental gradient of positional information but by the functional state of the genes of the bithorax complex in each metamere. The dorsal and ventral branches of the operculum line react differently, the dorsal branch being more sensitive to the effect of loss of function mutations (bxd, iab-2 k), the ventral branch more affected by gain of function mutations (Hab). In some cases the effects of the mutations on the operculum line differed from those in the adult, suggesting a difference in sensitivity of larval hypodermal cells and histoblast cells to the functional gene products of the bithorax complex.
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    Development genes and evolution 180 (1976), S. 73-77 
    ISSN: 1432-041X
    Keywords: Ecdysones ; Imaginal discs ; Fat body ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary The effect of suboptimal levels of α-ecdysone on the differentiation in vitro ofDrosophila melanogaster wing discs was enhanced by the addition of larval fat body to the cultures. However, similar experiments with β-ecdysome showed no enhancement. It is suggested that a partial conversion of α-ecdysone to β-ecdysone by the fat body may well account for these results.
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    Development genes and evolution 181 (1977), S. 309-320 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Male foreleg disc ; Pattern regulation
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    Notes: Summary 1. The developmental potentials of the four quadrants of the male foreleg disc ofDrosophila melanogaster were analysed by culturing excised quadrants for 3 days and 10 days in adult hosts prior to metamorphosis. 2. The cultured pieces underwent different types of pattern regulation in a circular direction. The upper medial piece was able to regenerate the missing structures of the disc, thus confirming the findings of earlier reports. The three remaining pieces could undergo pattern duplication in mirror-image symmetry. The lower medial piece revealed in addition a slight capacity for regeneration from the vertical cut surface. 3. The duplicating pieces differed markedly in their frequencies of pattern duplication: duplications occurred with very high frequencies in lower medial pieces, with intermediate frequencies in upper lateral pieces, and with very low frequencies in lower lateral pieces. 4. Both lower lateral and upper lateral pieces underwent a progressive loss of most markers with increasing culture time. 5. Claws were regenerated solely by upper medial pieces. 6. Transdetermined structures, too, were encountered only in upper medial pieces. 7. The results are discussed with respect to the two major current models of pattern regulation in imaginal discs, the “gradient model” and the “clock model”. 8. It is suggested that the differences in the frequencies of pattern duplication reflect the unequal spacing of circular positional values within the three duplicating quadrants. Under this assumption the data indicate a progressive decrease in the density of circular positional values with increasing distance from the upper medial quadrant of the disc.
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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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    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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    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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    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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    Development genes and evolution 190 (1981), S. 365-369 
    ISSN: 1432-041X
    Keywords: Selector genes ; Determination ; Homoeotic mutations ; Drosophila melanogaster
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    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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    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
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    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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    Development genes and evolution 193 (1984), S. 226-233 
    ISSN: 1432-041X
    Keywords: Wing development ; Sensory neurons ; Differentiation ; Axonal outgrowth ; Drosophila melanogaster
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    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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  • 55
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    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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  • 56
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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
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    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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  • 57
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    Development genes and evolution 196 (1987), S. 279-285 
    ISSN: 1432-041X
    Keywords: Drosophila melanogaster ; Mutant oogenesis ; Time-lapse filming ; Maternal effect ; Pattern formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Drosophila females homozygous for the mutation dicephalic occasionally produce ovarian follicles with a nurse-cell cluster on each oocyte pole (dic follicles). Most dic follicles contain 15 nurse cells as in the normal follicle, but the total nurse-cell volume is larger in dic follicles; this is in keeping with the increase in DNA content recently described. However, the relative increase in oocyte volume during nurse-cell regression (from stage 10B onward) is not significantly larger in dic than in normal follicles. Time-lapse recordings in vitro show that, as a rule, both nurse cell clusters in a dic follicle export cytoplasm to the oocyte but nurse-cell regression remains incomplete at both poles and the persisting remnants of the nurse cells cause anomalies in chorion shape. The kinematics of cytoplasmic transfer are less aberrant at that oocyte pole which harbours the germinal vesicle. Possible links are discussed between these anomalies of oogenesis and the double-anterior embryonic patterns observed in the majority of developing dic eggs.
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  • 58
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    Cellular and molecular life sciences 41 (1985), S. 106-108 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; Drosophila simulans ; intrapopulational variation ; interspecific crossing ; hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intrapopulational variation on interspecific crossing ability betweenD. melanogaster andD. simulans has been measured. When themelanogaster females andsimulans males were crossed, hybridization ranged from 3 to 34%, the female component of variation being more important than the male component. This point is discussed in relation with the role played by each sex in sexual isolation.
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  • 59
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    Cellular and molecular life sciences 42 (1986), S. 1283-1285 
    ISSN: 1420-9071
    Keywords: Hybrid dysgenesis ; cytotype-suppressor ; female sterility ; Drosophila melanogaster
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    Topics: Biology , Medicine
    Notes: Summary Using F1 female sterility as an indicator of hybrid dysgenesis (HD), we determined the inducing as well as the cytotype-suppressor properties of several P-strains. The data indicate that in P-M hybrid dysgenesis there is not only one type of inducer/suppressor system operative; in some P-strains more than one such system must be present.
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  • 60
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; dichlorvos ; malathion ; viability tests ; drastic mutants
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    Topics: Biology , Medicine
    Notes: Summary Viability tests were performed on second and third chromosomes from lines ofDrosophila melanogaster selected for increased resistance to the organophosphorus insecticides dichlorvos and malathion, in order to evaluate the accumulation of drastic alleles. Our results show that malathion reduces significantly the relative viability of chromosome 3 and also increases the frequency of drastic alleles in this chromosome, while dichlorvos increases significnatly the frequency of drastic alleles in chromosome 2.
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  • 61
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    Cellular and molecular life sciences 44 (1988), S. 76-79 
    ISSN: 1420-9071
    Keywords: Drosophila melanogaster ; sexual behaviour ; ageing ; memory mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In response to an interruption of their courtship, males ofD. melanogaster exhibit a lasting sexual arousal (up to 30–60 min), expressed behaviourally by characteristic wing displays. A study of this effect centered on two ‘memory mutants’ of different ages suggests that it can be related to an ageing-dependent perseveration, rather than to modifications in memory processing.
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  • 62
    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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    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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  • 64
    ISSN: 1573-4927
    Keywords: aldehyde oxidase ; xanthine dehydrogenase ; Drosophila melanogaster ; molybdenum
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two new mutants, deficient in aldehyde oxidase and xanthine dehydrogenase, have been isolated from a wild-type stock of Drosophila melanogaster and have been provisionally termed lxd c and lxd d, respectively, as both mutants appear to be allelic with lxd (low xanthine dehydrogenase). An analysis has been made of the effects of dietary molybdenum on lxd, lxd c, lxdd, lao (low aldehyde oxidase), mal (maroon-like eye color), and pac (Pacific) wild-type flies. On the lower dietary levels of 10 −3 M and 10 −2 M molybdenum, increases in specific activity of both enzymes were observed only in lxd. Furthermore, two- to three-fold increases in specific activity of both enzymes occurred in all strains, except mal, when cultured on 5×10 −2 M molybdenum. The lxd and lxd c strains failed to survive on this high concentration of the ion. Similar concentrations of molybdenum had no effect in vitro. An extra electrophoretic band of xanthine dehydrogenase was observed on polyacrylamide gel from extracts of wild-type flies cultured on certain levels of molybdenum, but its appearance was not always correlated with the increases in specific activity.
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    Biochemical genetics 14 (1976), S. 357-371 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; poly(A)-containing RNA
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The size range of poly(A)-containing RNA from Drosophila melanogaster embryos has been estimated by hybridization with 3H-labeled poly(U) and subsequent fractionation on sucrose gradients. The median size of nuclear poly(A)-containing RNA is about 30 S (6000 nucleotides), and the median size of cytoplasmic poly(A)-containing RNA is about 17 S (1800 nucleotides). The relationship of these sizes to messenger RNA needed to code for protein and to the length of DNA contained in a chromomere is discussed.
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    Biochemical genetics 14 (1976), S. 259-270 
    ISSN: 1573-4927
    Keywords: GTP cyclohydrolase ; Drosophila melanogaster ; pteridines ; dihydroneopterin triphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The first enzyme (named GTP cyclohydrolase) in the pathway for the biosynthesis of pteridines has been partially purified from extracts of late pupae and young adults of Drosophila melanogaster. This enzyme catalyzes the hydrolytic removal from GTP of carbon 8 as formate and the synthesis of 2-amino-4-hydroxy-6-(d-erythro-1′,2′,3′-trihydroxypropyl)-7,8-dihydropteridine triphosphate (dihydroneopterin triphosphate). Some of the properties of the enzyme are as follows: it functions optimally at pH 7.8 and at 42 C; activity is unaffected by KCl and NaCl, but divalent cations (Mg2+, Mn2+, Zn2+, and Ca2+) are inhibitory; the K m for GTP is 22 μm; and the molecular weight is estimated at 345,000 from gel filtration experiments. Of a number of nucleotides tested, only GDP and dGTP were used to any extent as substrate in place of GTP, and these respective compounds were used only 1.8% and 1.5% as well as GTP.
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    Biochemical genetics 14 (1976), S. 611-617 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; phenol oxidases ; spectrophotometry ; electrophoresis ; suppression ; ribosomal proteins
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An interaction between the lozenge gene and the suppressor of forked gene of Drosophila melanogaster has been investigated both spectrophotometrically and electrophoretically. The nature of this interaction is such that certain lozenge alleles appear to be phenotypically suppressed while others are enhanced or unaffected, and the results reported demonstrate that the effect can clearly be observed at the biochemical level. Earlier observations have suggested that the suppressor of forked gene codes for a ribosomal protein, and this hypothesis is discussed.
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    Biochemical genetics 15 (1977), S. 93-100 
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase (ADH) ; genetic polymorphism ; selection ; Drosophila melanogaster
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In the natural populations +Tüb, +Prov, and +Rov, similar Adh F allele frequencies occur (q F=0.11, 0.18, and 0.08, respectively). However, there is a discrepancy in that the Adh F allele in +Tüb is closely linked to the lethal factor 1(2)Stm, which reduces relative fitness of the F phenotype to zero. In spite of this, polymorphism is maintained also in +Tüb, because the heterozygotes are superior to the homozygous S type (relative fitness=0.88). Under laboratory culture conditions, in +Tüb the relative fitness of the S genotype further decreases to 0.6. After outcrossing the lethal factor, relative fitnesses for S, FS, and F become 0.6, 1, and 0.48, respectively, implying that fitness for S remains the same. Relative values for S, FS, and F in +Prov, not affected by the lethal factor, are calculated by the maximum average fitness method to be 1, 1.2, and 0.2 under the assumption that heterozygous FS are similarly superior to S as in the natural +Tüb population and all allele frequencies found are stable equilibrium values.
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  • 69
    ISSN: 1573-4927
    Keywords: l-glycerol-3-phosphate dehydrogenase (α-GPDH) ; isozymes ; development ; Drosophila melanogaster
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The basis for the differentiation of l-glycerol-3-phosphate dehydrogenase (α-GPDH) into larval and adult isozymes in Drosophila melanogaster was investigated by the correlation of a lack of appearance of each isozyme during development within Drosophila bearing α-GPDH “null” alleles and by the study of a putative conversion factor. Conversion studies indicate the presence of a heat-labile RNase-resistant conversion factor present in crude larval extracts with the ability to convert GPDH-1 to GPDH-2 and GPDH-3 but not vice versa. In addition, “null” mutations at the Gpdh locus obliterate all isozymatic species of α-GPDH in all developmental stages. These observations suggest that all α-GPDH isozymes are the product of a single structural gene and that the multiple forms of this enzyme arise during successive developmental stages through an epigenetic modification of the primary Gpdh + polypeptide. Finally, observations are reported which bear on the functional divergence of the α-glycerophosphate cycle in the adult and larval stage of development.
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  • 70
    ISSN: 1573-4927
    Keywords: allozymes ; thermostability ; alcohol dehydrogenase ; Drosophila melanogaster ; natural populations
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Drosophila melanogaster collected from natural populations were examined fo thermostability variants within electrophoretic mobility classes of two enzymes. In alcohol dehydrogenase, two discrete forms of the “slow” allozyme and three discrete forms of the “fast” allozyme were revealed by postelectrophoretic treatments ranging from 15 sec at 40 C to 40 sec at 43 C. All variants have been mapped to within 0.7 unit of the Adh locus. Results of a geographic survey indicate that two alleles giving rise to fast-moderate and slow-moderate allozymes are common everywhere; other variants have a collective frequency ranging from 0% to 7%. In a test of the possibility that the rare Adh alleles could be generated by intragenic recombination between the two common alleles, electrophoresis and heat treatment of progeny recombinant for flanking markers of Adh revealed no new allozymes. Among 27 stocks containing slow α-glycerophosphate dehydrogenase allozymes and 109 fast stocks, heat treatments revealed no additional variation.
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  • 71
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; GTP cyclohydrolase ; development ; pteridine biosynthesis ; mutants
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    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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  • 72
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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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  • 74
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    Keywords: Drosophila melanogaster ; alcohol tolerance ; alcohol utilization ; alcohol dehydrogenase ; aldehyde oxidase ; allozymes
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    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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  • 75
    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 20 (1982), S. 1117-1129 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; amylase ; dietary effects ; enzyme quantity
    Source: Springer Online Journal Archives 1860-2000
    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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  • 77
    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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  • 78
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; common and rare allozymes ; esterase-6 ; biochemical properties
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    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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  • 79
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; esterase 6 ; isozymes ; enzyme kinetics
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    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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  • 80
    ISSN: 1573-4927
    Keywords: sepiapterin synthase ; variegation ; purple ; Drosophila melanogaster ; pteridine eye pigments ; drosopterin
    Source: Springer Online Journal Archives 1860-2000
    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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  • 81
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    Biochemical genetics 17 (1979), S. 1131-1144 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; enzyme polymorphism ; G6PD ; 6PGD ; enzyme activity
    Source: Springer Online Journal Archives 1860-2000
    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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  • 82
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    Biochemical genetics 23 (1985), S. 363-378 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; Minute mutations ; yolk polypeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Minutes have been considered for some time to be mutant at the sites of synthesis of some components of the protein synthetic apparatus. To study the hypothetical relationship between Minutes and suboptimal translation, a group of abundant proteins, the yolk polypeptides, was assayed in outcrossed females bearing M(3)w, M(3)h y , or M(1)n mutations. Recently emerged Minute females contained a lower amount of yolk polypeptides, in both ovarian and nonovarian tissues, than their non-Minute sisters. This low level correlated with the lower abundance of cytoplasmic RNA in Minutes compared to control females. By 1 week of age, both M(3)w and their non-Minute sibs contained the same amount of yolk polypeptides and the corresponding mRNA. The double heterozygote, ap 4/+;M(3)w/+, did not differ in yolk polypeptide content from control flies. M(3)w females demonstrated reduced fecundity during the period of low yolk polypeptide content but gradually increased egg deposition as yolk polypeptide levels rose. These results suggest that the low protein levels are due to the slower maturation of M(3)w, and not to less efficient translation machinery.
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  • 83
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    Biochemical genetics 23 (1985), S. 465-482 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; acid phosphatase ; gene regulation ; quantitative variants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have examined 111 wild Drosophila melanogaster lines for cis-acting quantitative variants of the Acph-1 gene, which codes for acid phosphatase-1 (ACPH). Three variants with obvious, reproducible phenotypes were isolated. All variants acted equally on all tissues and developmental stages examined. No recombinants were detected between one quantitative variant and the site determining the electrophoretic mobility of Acph-1 among 3885 flies examined. Several enzymatic properties of the variant enzymes were tested, including the K m values for two substrates, inhibition by three different inhibitors, and thermal stability; the variant enzymes behaved identically to the wild-type enzyme in all cases. Immunological titration experiments showed that the variant enzymes had the same enzyme activity per molecule of ACPH as the wild-type enzyme. These results suggest that the quantitative variants we have identified are altered in the regulatory portion of Acph-1 so as to produce altered numbers of normal ACPH molecules.
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  • 84
    ISSN: 1573-4927
    Keywords: phosphoglucomutase ; Drosophila melanogaster ; thermostability allozymes ; geographic variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Genetic polymorphism for electrophoretic and heat-sensitive alleles is known at the phosphoglucomutase (Pgm) locus in Drosophila melanogaster. Analysis of the distribution of electrophoretic and thermosensitive (ts) alleles was carried out in natural populations from Canada and West Africa and compared with already known data on Italian populations [Trippa, G., Loverre, A., and Catamo, A. (1976). Nature 260:42]. The data show the existence of five common alleles, Pgm 1.00,tr, Pgm 1,00,ts, Pgm 0.70,ts, Pgm 1.20,ts, and Pgm 1.50,tr, and two rare alleles, Pgm 0.55,ts and Pgm 1.20,tr. The most frequent allele is always Pgm 1.00,tr; the second most common allele is always of the ts type. The cumulated frequencies of ts alleles in the populations varies between 11 and 32%. The heat stability polymorphism is present in all populations examined and shows again the uniform geographic pattern that has been found for electrophoretic variation at this locus.
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  • 85
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila melanogaster ; alleloenzymes ; active-site titration ; enzymatic rate assay ; catalytic-center activity ; enzymology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A rapid and reproducible enzymatic rate assay for the quantitative determination of the concentration of active sites is presented for the alleloenzymes AdhS and AdhF from Drosophila melanogaster. Using this procedure the turnover numbers as catalytic-center activities were found to be 12.2 sec−1 for AdhF and 3.4 sec−1 for AdhS with secondary alcohols. This showed a slower dissociation of the coenzyme from the binary enzyme-NADH complex with AdhS and hence a stronger binding of NADH to this alleloenzyme. With ethanol, the catalytic-center activity was 1.4 sec−1 for AdhS and 2.8 sec−1 for AdhF, and hence the single amino acid mutation distinguishing the two alleloenzymes also affected hydride transfer.
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  • 86
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    Biochemical genetics 23 (1985), S. 321-328 
    ISSN: 1573-4927
    Keywords: polymorphism ; Drosophila melanogaster ; esterase-6 ; phosphoglucomutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electrophoretic studies of the degree and pattern of polymorphism at two third-chromosome loci, esterase-6 (Est-6) and phosphoglucomutase (PGM), were carried out in three Drosophila melanogaster populations collected from different localities in Iraq: Mosul, Tuwaitha, and Basrah. The results show that only the Tuwaitha population was polymorphic for both loci; the other two populations were polymorphic for Est-6 and monomorphic for PGM. The allele frequency changes at both loci were followed for 20 generations in an experimental cage derived from the Tuwaitha population; it was found that there is a deviation from Hardy-Weinberg equilibrium at both loci toward the homozygote.
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  • 87
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    Biochemical genetics 23 (1985), S. 539-555 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; purines ; auxotrophs ; adenosine ; guanosine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mutations at three second-chromosomal loci of Drosophila melanogaster have been isolated, mapped, and shown to be purine nucleoside auxotrophs. Two of the loci, adenosine2 and adenosine3, located at map positions 18.4 and 20, respectively, produce mutations which are supplementable with adenine, adenosine, and inosine. Guanosine supplements mutations at the burgundy locus (55.7); this locus was described previously through a pteridine eye-color defect but identified as an auxotrophic locus after the isolation of a new allele, bur gua2-1 . The mutation ade2-1 also has defective pteridine metabolism.
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  • 88
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; cadmium ingestion ; cadmium excretion ; genetics of cadmium toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two strains of Drosophila melanogaster represent the extremes in resistance and sensitivity to the lethal effects of CdCl2. The strain containing the mutations vermilion and brown (v; bw) and the strain Austin had LC50's of 3.3 and 1.3mm CdCl2, respectively. The three major chromosomes from these two strains were assorted genetically into the six possible combinations. The measured LC50's for CdCl2 for these six genotypes fell into two groups according to the X chromosome; those containing the X chromosome from v; bw had LC50's 0.5–1.0mm greater than those in which the X chromosome was from Austin. Since the parent strains differed by 2mm, we suggest that the X chromosome is a major, but not the sole, site of genes to produce resistance to CdCl2. When 109Cd was in the diet the uptake by v; bw and Austin over 2 days was the same. After 4 days of uptake, the Austin strain excreted the 109Cd five times faster than v; bw but the six genotypes did not differ appreciably in excretion rate from one another and resembled the sensitive parent Austin more than the resistant one. Thus a second process is indicated that distinguishes resistance to CdCl2 that apparently is not associated with the X chromosome.
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  • 89
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; molybdoenzymes ; low xanthine dehydrogenase mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The biochemical effects of several newly induced low xanthine dehydrogenase (lxd) mutations in Drosophila melanogaster were investigated. When homozygous, all lxd alleles simultaneously interrupt each of the molybdoenzyme activities to approximately the same levels: xanthine dehydrogenase, 25%; aldehyde oxidase, 12%; pyridoxal oxidase, 0%; and sulfite oxidase, 2% as compared to the wild type. In order to evaluate potentially small complementation or dosage effects, mutant stains were made coisogenic for 3R. These enzymes require a molybdenum cofactor, and lxd cofactor levels are also reduced to less than 10% of the wild type. These low levels of molybdoenzyme activities and cofactor activity are maintained throughout development from late larval to adult stages. The lxd alleles exhibit a dosage-dependent effect on molybdoenzyme activities, indicating that these mutants are leaky for wild-type function. In addition, cofactor activity is dependent upon the number of lxd + genes present. The lxd mutation results in the production of more thermolabile XDH and AO enzyme activities, but this thermolability is not transferred with the cofactor to a reconstituted Neurospora molybdoenzyme. The lxd gene is localized to salivary region 68 A4-9, 0.1 map unit distal to the superoxide dismutase (Sod) gene.
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  • 90
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    Biochemical genetics 27 (1989), S. 679-688 
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; null allele ; DNA rearrangement ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An alcohol dehydrogenase null activity allele,Adh nAH52 , extracted from a natural population ofDrosophila melanogaster has been cloned and sequenced. Compared with the wild-type consensus sequence, the nucleotide sequence ofAdh nAH52 contains eight extra bases in intron 2, adjacent to the 5' splice site. It seems likely that the extra bases result from two structural changes, with a 10-base pair insertion at the same site as a 2-base pair deletion. The insertion includes an 8-base pair duplication of an adjoining region. This structural change alters transcription to give rise to an mRNA which is longer than normal and at 10% of the wild-type level.
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  • 91
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    Biochemical genetics 27 (1989), S. 379-393 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; glucose-6-phosphate dehydrogenase (G6PD) ; transposable genetic element ; positive regulation ; chromatin structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In a previous study, we have shown that the three high-G6PD activity mutants are characterized by insertion of the Ins1 sequence consisting of a core sequence flanked by two defective P elements (KP and KP'; the 32nd base of the KP was replaced by guanine in the KP') in front of exonI of the G6PD gene and that the sequence responsible for positive regulation of the G6PD gene expression might be the core sequence but not the flanking KP and KP' elements. The core sequence is composed of either one or two identical units in each mutant. In this report we present evidence (1) that insertion of the Ins1 sequence gives rise to overproduction of G6PD mRNA, (2) that the length and the 5′ end of G6PD mRNA do not differ in wild-type and three mutants, (3) that the insertion site of the Ins1 sequence is the same in the mutants, and (4) that each unit of the core sequence has a pair of DNase I-hypersensitive sites. The possibility exists that the binding of some regulatory proteins to the DNase I-hypersensitive sites might accelerate the transcription rate of the G6PD gene.
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  • 92
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    Biochemical genetics 27 (1989), S. 379-393 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; glucose-6-phosphate dehydrogenase (G6PD) ; transposable genetic element ; positive regulation ; chromatin structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In a previous study, we have shown that the three high-G6PD activity mutants are characterized by insertion of the Ins1 sequence consisting of a core sequence flanked by two defective P elements (KP and KP'; the 32nd base of the KP was replaced by guanine in the KP') in front of exonI of the G6PD gene and that the sequence responsible for positive regulation of the G6PD gene expression might be the core sequence but not the flanking KP and KP' elements. The core sequence is composed of either one or two identical units in each mutant. In this report we present evidence (1) that insertion of the Ins1 sequence gives rise to overproduction of G6PD mRNA, (2) that the length and the 5′ end of G6PD mRNA do not differ in wild-type and three mutants, (3) that the insertion site of the Ins1 sequence is the same in the mutants, and (4) that each unit of the core sequence has a pair of DNase I-hypersensitive sites. The possibility exists that the binding of some regulatory proteins to the DNase I-hypersensitive sites might accelerate the transcription rate of the G6PD gene.
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  • 93
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; Notch locus ; wing morphology ; phenocopies ; choline dehydrogenase ; dihydroorotate dehydrogenase ; xanthine dehydrogenase (O2) ; sarcosine dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The biochemical action of the Notch locus whose mutants cause morphological aberrations in flies, viz., notches of wings and bristle multiplication, has been analyzed (1) by the addition to the food medium of enzyme inhibitors causing phenocopies of Notch and (2) by comparison of enzyme activity patterns of Notch mutants with different degrees of phenotypic expression. Notch phenocopies were induced by inhibitors of enzyme activities in two biochemical pathways: (1) the de novo pyrimidine synthesis by 5-methylorotate (inhibitor of dihydroorotate dehydrogenase) and (2) the choline shunt by amobarbital (inhibits choline dehydrogenase) and methoxyacetate (inhibits sarcosine dehydrogenase). The inhibition of de novo pyrimidine synthesis prevents the production of deoxyuridine-5-phosphate, the substrate for the synthesis of thymidine-5-phosphate via thymidylate synthase, whereas the inhibition of the choline shunt prevents the production of HCHO groups and glycine, both of which are involved in the synthesis of 5,10-methylenetetrahydrofolate, which is a cofactor of thymidylate synthase. It was already known that the inhibition of the latter enzyme in vivo induces Notch phenocopies. Notch mutants with a strong morphological expression show low enzyme activities for dihydroorotate dehydrogenase and choline dehydrogenase. Both are flavoprotein enzymes linked to the respiratory chain. The correspondence between the low enzyme activities in Notch mutants with a strong morphological expression and the phenocopying effect of antimetabolites on these enzymes in the two biochemical pathways involved strongly suggests that the morphological effects of Notch on flies are a consequence of lowered activities of choline dehydrogenase and dihydroorotate dehydrogenase.
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  • 94
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    Keywords: population ; Drosophila melanogaster ; D. simulans ; electrophoresis ; heterozygosity, allozymes ; genetic strategies ; adaptation ; bottleneck effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An electrophoretic study was carried out to compare the geographic pattern of genetic variation in Drosophila simulans with that of its sibling species, Drosophila melanogaster. An identical set of 32 gene-protein loci was studied in four geographically distant populations of D. simulans and two populations of D. melanogaster, all originating from Europe and Africa. The comparison yielded the following results: (1) tropical populations of D. simulans were, in terms of the number of unique alleles, average heterozygosity per locus, and percentage of loci polymorphic, more variable than conspecific-temperate populations; (2) some loci in both species showed interpopulation differences in allele frequencies that suggest latitudinal clines; and (3) temperate-tropical genetic differentiation between populations was much less in D. simulans than in D. melanogaster. Similar differences between these two species have previously been shown for chromosomal, quantitative, physiological, and middle-repetitive DNA variation. Estimates of N m (number of migrants per generation) from the spatial distribution of rare alleles suggest that both species have similar levels of interpopulation gene flow. These observations lead us to propose two competing hypotheses: the low level of geographic differentiation in D. simulans is due to its evolutionarily recent worldwide colonization and, alternatively, D. simulans has a narrower niche than D. melanogaster. Geographic variation data on different genetic elements (e.g., mitochondrial DNA, two-dimensional proteins, etc.) are required before these hypotheses can be adequately tested.
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  • 95
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    Biochemical genetics 25 (1987), S. 41-51 
    ISSN: 1573-4927
    Keywords: population bottleneck ; Drosophila melanogaster ; D. pseudoobscura ; genetic variation ; sequential gel electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We report the results of a sequential gel electrophoretic study of protein variation in Drosophila melanogaster and its comparison with D. pseudoobscura. The number of alleles and mean heterozygosity were lower in D. melanogaster than in D. pseudoobscura. On the other hand, geographical populations of Drosophila melanogaster have been shown to be much more differentiated than those of D. pseudoobscura. The results suggest that in D. melanogaster low-frequency alleles have been lost during the colonization process and that major alleles have become differentiated among populations. Population bottlenecks, due to various causes, appear to have played a significant role in the shaping of genetic variation in natural populations of many species. It is proposed that a comparison of genetic variation at homologous gene loci between related species can bring out effects of historical bottlenecks and provide an alternative approach for analyzing causes of genetic variation in natural populations.
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  • 96
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    Biochemical genetics 25 (1987), S. 779-788 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; acetylcholinesterase ; particularization ; 20-OH-ecdysone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Particulate and soluble acetylcholinesterase (AChE) (EC 3.1.1.7) activities were measured and the pattern of isozyme variants was established by acetylthiocholine and α-naphthyl acetate staining during the life cycle of Drosophila melanogaster. The compartmentalization and the pattern of AChE forms changed very little with the development of the fly. The AChE isozyme variants are greatly reduced or abolished in embryos homozygous for Ace 126, a representative mutant of the AChE region. One of the isozyme variants was suppressed by 20-OH-ecdysone treatment in first-instar larvae without affecting the viability. The comparison of the map of AChE variants and the known transcript of the AChE gene in embryos are discussed.
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  • 97
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; glutamine synthetase isozymes ; structural comparison
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Glutamine synthetase II was purified from Drosophila melanogaster adults. It was completely separable from the isozyme glutamine synthetase I by means of DEAE chromatography. The complete enzyme has an apparent molecular weight of 360,000. After two-dimensional electrophoresis it gave a single molecular species with an apparent molecular weight of 42,000. Structural analysis of the two isozymes showed that they are different both in subunit molecular weight and in isoelectric point. Peptide maps of the purified subunits showed considerable dissimilarity. Glutamine synthetase II is more active than glutamine synthetase I in the transferase assay, while the opposite is true in the biosynthetic assay. The kinetic parameters were determined, showing again noteworthy differences between the two isozymes. We therefore conclude that two forms of glutamine synthetase are present in Drosophila, with different primary structures, different kinetic behavior, and the possibility of different functional properties.
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  • 98
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    Biochemical genetics 13 (1975), S. 603-613 
    ISSN: 1573-4927
    Keywords: transport mutants ; eye color mutants ; kynurenine ; Drosophila melanogaster ; Malpighian tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Kynurenine-H 3 transport and conversion to 3-hydroxykynurenine were studied in organ culture using the Malpighian tubules and developing eyes from wild type and the eye color mutants w, st, 1td, ca, and cn of Drosophila melanogaster. Malpighian tubules from wild type have the ability to concentrate kynurenine and convert it to 3-hydroxykynurenine. The tubules from w, st, 1td, and ca are deficient in the ability to transport kynurenine, as are the eyes of the mutants w, st, and 1td. This defect in kynurenine transport provides a physiological explanation for the phenotypic properties of the mutants. The relationship of these measurements to previous observations on these eye color mutants is discussed and the transport defect hypothesis is consistently supported. We have concluded that several of the eye color mutants in Drosophila are transport mutants.
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  • 99
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; GTP cyclohydrolase ; pteridine biosynthesis ; development ; mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The enzyme guanosine triphosphate cyclohydrolase (GTP cyclohydrolase), which in bacteria is known to be the first enzyme in the biosynthetic pathway for the synthesis of pteridines, has been discovered in extracts of Drosophila melanogaster. Most of the enzyme (80%) is located in the head of the adult fly. An analysis of enzyme activity during development in Drosophila has revealed the presence of a relatively small peak of activity at pupariation and a much larger peak that appears at about the time of eclosion. Enzyme activity declines rapidly as the fly ages. Analyses for the production of the typical pteridine pigments of Drosophila have indicated that the small peak of GTP cyclohydrolase activity evident at pupariation coincides with the appearance of isoxanthopterin, sepiapterin, and pterin, and the larger peak at eclosion roughly corresponds to the accumulation of drosopterin as well as to the appearance in larger amounts of pterin and sepiapterin. These observations strongly suggest that in Drosophila, like bacteria, GTP cyclohydrolase is involved in the biosynthesis of pteridines. Analyses of a variety of zeste mutants of Drosophila melanogaster have shown that these mutants all contain GTP cyclohydrolase equal approximately to the amount found in the wild-type fly. These observations do not support the suggestions made by Rasmusson et al. (1973) that zeste is the structural locus for GTP cyclohydrolase.
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  • 100
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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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