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  • Chemistry
  • Chromatographie, Dünnschicht
  • Drosophila melanogaster
  • Humans
  • Life and Medical Sciences
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  • Springer  (372)
  • 1990-1994  (142)
  • 1975-1979  (230)
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  • 1
    Digitale Medien
    Digitale Medien
    Geographical variation in habitat choice and host suitability in the parasitoidAsobara rufescens (1994)
    Springer
    Entomologia experimentalis et applicata 72 (1994), S. 109-114 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Asobara rufescens ; parasitoid ; geogrphical variation ; microhabitat choice ; genetical isolation ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the Netherlands,Asobara rufescens (Föster) (Hymenoptera: Braconidae) is a parasitoid of drosophilid larvae in decaying plant material. In several places in the Mediterranean, parasitoids looking very similar toA. rufescens were collected on fermenting substrates. A hybridization experiment showed that the parasitoids were indeedA. rufescens. In an olfactometer PortugueseA. rufescens do not have a preference for either the odour of yeast or decaying leaves, while their Dutch conspecifics prefer the odour of decaying leaves. The survival probability of PortugueseA. rufescens inDrosophila melanogaster Meigen (Diptera: Drosophilidae), a species typical for fermenting substrates, is much higher than the survival probability of DutchA. rufescens in this host species. It is hypothesized that decaying plant material may be unsuitable for drosophilid larvae during part of the year in the Mediterranean, forcingA. rufescens there to broaden its microhabitat choice. The use of fermenting substrates bringsA. rufescens in contact with its siblingA. tabida Nees, a species typical for fermenting substrates in most of Europe. PortugueseA. rufescens appear to be genetically isolated fromA. tabida. In the Netherlands, where the two species occupy different microhabitats, there is only a premating barrier.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02383545
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  • 2
    Digitale Medien
    Digitale Medien
    Behavioral analysis of the choice of oviposition site by single females ofDrosophila Melanogaster (Diptera: Drosophilidae) (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 571-581 
    Details
    ISSN: 1572-8889
    Schlagwort(e): insect behavior ; Drosophila melanogaster ; oviposition choice ; gregarious distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The oviposition behavior of single females of Drosophila melanogasterwas studied in population cages over 24 h. Each female shows a different behavior, but they can be arbitrarily separated into those which concentrate their egg laying in only one tube and those which spread it over more than two tubes. A comparison is made between females extracted from the Valdivian population and flies from lines selected for high and low aggregation. When “one-tube” females were grouped and compared with “more-than-one-tube” females, the aggregation indices between these groups were significantly different.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048005
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  • 3
    Digitale Medien
    Digitale Medien
    The influence of age and experience with conspecifics on territorial behavior inDrosophila melanogaster (1990)
    Springer
    Journal of insect behavior 3 (1990), S. 1-12 
    Details
    ISSN: 1572-8889
    Schlagwort(e): Drosophila melanogaster ; territoriality ; age ; aggressive behavior ; experience
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Drosophila melanogastermales initiated aggressive behavior toward other males and defended territories several hours after they were able to court and mate females. Males that were 3 days or more posteclosion were more successful at holding territories than younger males. Three-day-old males established territories more readily and escalated more often against territory residents than males that were 1 day old. Residents did not usually force young males from territories until they were a few hours posteclosion. The development of territorial behavior was not affected by familiarity or prior exposure to females. Males held in isolation established territories more quickly and behaved more aggressively than males held in groups. Males that previously held territories were more likely to reestablish them after a disturbance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049191
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  • 4
    Digitale Medien
    Digitale Medien
    Behavioral and electroantennogram analysis of olfactory stimulation inlozenge: ADrosophila mutant lacking antennal basiconic sensilla (Diptera: Drosophilidae) (1991)
    Springer
    Journal of insect behavior 4 (1991), S. 683-705 
    Details
    ISSN: 1572-8889
    Schlagwort(e): Drosophila melanogaster ; sensillum mutant ; behavioral genetics ; olfactory stimulation ; locomotor behavior ; electroantennogram recording
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two alleles of the mutant lozengeof Drosophila melanogaster, lzand lz3,lack basiconic sensilla on the antennal funiculus. To elucidate the role of these sensilla for the perception of food odors, we studied the locomotor behavior and the electroantennogram (EAG) activity of lozenge flies in response to olfactory stimuli. The significance of basiconic sensilla on the maxillary palps was assessed by testing the locomotion of flies surgically deprived of their palps. The behavioral data suggest that antennal and maxillary basiconic sensilla may be important receptors for short chain alcohols and organic acids but less crucial receptors for acetates, aldehydes, and ketones. In agreement with this interpretation, EAG responses to alcohols (but not to esters) were found to be markedly lower in lozengethan in the wild type.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01052225
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  • 5
    Digitale Medien
    Digitale Medien
    Interactions between searching strategies ofDrosophila parasitoids and the polymorphic behavior of their hosts (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 161-175 
    Details
    ISSN: 1572-8889
    Schlagwort(e): rover/sitter ; larval behavior ; genetics ; Drosophila melanogaster ; parasitoid success ; field population
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two strains of Drosophila melanogaster, “rover” and “sitter,” differing in locomotion while foraging were simultaneously exposed to females of either Leptopilina boulardi or Ganaspis xanthopoda (parasitic Hymenoptera). These two parasitoids show different modes of host-searching behavior, ovipositor searching, or vibrotaxis, respectively. L. boulardi parasitized the sitter host strain significantly more than the rover. In contrast, G. xanthopoda parasitized the rover strain more than the sitter. In one case, L. boulardi selected far more sitters than rovers in population cage experiments. We also describe the frequencies of rovers and sitters in three natural populations where the local parasitoid community may have partially contributed to the differences in rover and sitter frequencies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049287
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  • 6
    Digitale Medien
    Digitale Medien
    Foraging behavior and encapsulation ability ofDrosophila melanogaster larvae: Correlated polymorphisms? (Diptera: Drosophilidae) (1994)
    Springer
    Journal of insect behavior 8 (1994), S. 305-314 
    Details
    ISSN: 1572-8889
    Schlagwort(e): polymorphism ; foraging behavior ; encapsulation ability ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Larvae ofDrosophila melanogaster are polymorphic with respect to their foraging behavior. “Rovers” move around, while “sitters” stay more in one place. This difference in movements while foraging may result in differences in the rate at which these larvae are attacked by hymenopteran parasitoids, especially by those that locate their hosts by reacting to the vibrations they make. From previous work it is known thatD. melanogaster larvae show intra- and interpopulation variation in their ability to destroy parasitoid eggs by encapsulation. If rovers have a higher probability to be attacked by a parasitoid, they may have a higher developed encapsulation system as compensation for this higher attack probability. Experiments show that rovers are indeed more often attacked byAsobara tabida, a vibrotactic (=reacting to vibrations) parasitoid, than sitters. However, foraging behavior and encapsulation ability appear to be independent of each other inD. melanogaster. This shows that the large variation between populations in encapsulation ability is not a reflection of the relative proportion of rovers and sitters in the populations. It also shows that parasitoids can be an important factor in the maintenance of the foraging behavior polymorphism, because a higher encapsulation ability is not a compensation for a higher attack probability.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01989360
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  • 7
    Digitale Medien
    Digitale Medien
    Evaluation ofDrosophila melanogaster as an alternative animal for studying the neurotoxicity of heavy metals (1992)
    Springer
    BioMetals 5 (1992), S. 111-120 
    Details
    ISSN: 1572-8773
    Schlagwort(e): Drosophila melanogaster ; evaluation ; neurotoxicity ; heavy metals
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Heavy metals cause irreversible neurobehavioral damage in many developing mammals, but the mechanisms of this damage are unknown. The influence of three heavy metal compounds, triethyllead chloride, lead acetate and cadmium chloride, on lethality, development, behavior and learning was studied using the fruit fly,Drosophila melanogaster. This animal was used because it allows hundreds of subjects to be assayed very easily in individual experiments and because it is a system in which toxicological questions might be answered by using the techniques of modern molecular genetics. When triethyllead chloride, lead acetate or cadmium chloride was placed in the medium, the larval LC50 (± standard error) was found to be 0.090±0.004, 6.60±0.64 and 0.42±0.04mm, respectively. Each of the tested compounds produced a dose-related delay in development. In particular, they caused a delay in the development of larvae to pupae. When larvae were reared on medium containing triethyllead chloride (0.06mm), lead acetate (3.07mm) or cadmium chloride (0.11mm), phototaxis, locomotion and learning were not inhibited. Since significant neurobehavioral effects were not observed under the experimental conditions used,Drosophila does not appear to be an appropriate animal for the genetic dissection of such effects of heavy metals during development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01062222
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  • 8
    Digitale Medien
    Digitale Medien
    Mating speed and the interplay between female and male courtship responses inDrosophila melanogaster (Diptera: Drosophilidae) (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 229-244 
    Details
    ISSN: 1572-8889
    Schlagwort(e): Drosophila melanogaster ; mating speed ; locomotor activity ; sexual activity ; courtship sequences
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The objective of this study was to compare measures of general activity and sexual behavior for various genotypes within a strain of Drosophila melanogaster, which had known differences in mating speed. Three inbred lines of D. melanogaster differed significantly in mating speed when tested in female-choice and in single-pair experiments. Analyses of locomotor activity and sexual activity of females and males revealed no significant differences between the inbred lines. An analysis of the interplay between female and male courtship behaviors enabled the examination of signal-response differences between the inbred lines. The inbred lines with intermediate and slow mean mating speed showed a decreased number of significant transitions between female and male behavioral responses. This decrease was more severe in the slow mating line. Further, the intermediate- and slow-mating females and males displayed courtship responses toward signals of the opposite sex that were different from those of the fastmating line. Models of the relationship between behavioral activity and mating speed in Drosophila are discussed and a different explanation for variation in mating speed among the three inbred lines is considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049291
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  • 9
    Digitale Medien
    Digitale Medien
    Dynamics of mating success in experimental groups ofDrosophila melanogaster (Diptera: Drosophilidae) (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 375-383 
    Details
    ISSN: 1572-8889
    Schlagwort(e): mating success ; male courtship ; male size ; Drosophila melanogaster ; sexual selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Determinants of male courtship success in Drosophila melanogasterwere examined in groups of five males sequentially presented with five individual females. Thirty-three percent of males never mated, while approximately half of the males mated two or three times. Rapid courtship initiation was associated with male success in early matings only. Male size was important for courtship outcome, but the size distributions of mating and nonmating males and their progeny numbers indicate balancing rather than directional selection on size- dependent courtship success.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049845
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  • 10
    Digitale Medien
    Digitale Medien
    How does Drosophila melanogaster overwinter? (1991)
    Springer
    Entomologia experimentalis et applicata 59 (1991), S. 51-58 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Overwintering ; Cold and freezing resistance ; Developmental duration ; Cold adaptation and evolution ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In temperate regions low temperatures seem to be the most restrictive factor for survival of Drosophila natural populations, which depends on the capacity of one or more developmental stages to resist unfavourable winter conditions. In this study we have attempted to answer the question of how D. melanogaster overwinters under natural temperature conditions. Only adults overwintered and no diapause was observed in any developmental stage. Thus, developmental duration becomes a decisive component with respect to overwintering potential and, therefore, the preadult stages are unlikely to overwinter. Possible evolutionary steps in adaptation to cold regions are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00187965
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  • 11
    Digitale Medien
    Digitale Medien
    Transposable element insertion patterns as test of contamination of aDrosophila melanogaster inbred line (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 164-166 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Drosophila melanogaster ; transposable elements ; inbred lines ; insertion pattern ; transposition rate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract A highly inbred line ofDrosophila melanogaster, stable for the insertion pattern of the transposable elements copia and mdg1, was experimentally contaminated by flies from another line. We show that the alien genome income is clearly detectable by the changes induced in the insertion profiles of transposable elements, even twenty generations later.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01984957
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  • 12
    Digitale Medien
    Digitale Medien
    A sulphated glycopeptide in human supragingival calculus extracts (1977)
    Springer
    Calcified tissue international 23 (1977), S. 13-17 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Dental calculus ; Glycopeptide ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary A method is described for the isolation and purification of a sulphated glycopeptide from human supragingival calculus. The compound was isolated after using EDTA treatment, 2 M CaCl2 extraction, proteolytic digestion, ethanol precipitation, and finally purified by DEAE cellulose chromatography. It migrated as a single component on cellulose acetate electrophoresis, and chemical and infrared spectral analysis showed the presence of covalently attached sulphate groups. The sulphated glycopeptide was distinguished from being a sulphated glycosaminoglycan.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012761
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  • 13
    Digitale Medien
    Digitale Medien
    Phylogenetic evidence for multiple Alu source genes (1992)
    Springer
    Journal of molecular evolution 35 (1992), S. 7-16 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Alu source genes ; Humans ; Gorillas ; Retrotransposition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A member of the young PV Alu sub-family is detected in chimpanzee DNA showing that the PV subfamily is not specific to human DNA. This particular Alu is absent from the orthologous loci in both human and gorilla DNAs, indicating that PV subfamily members transposed within the chimpanzee lineage following the divergence of chimpanzee from both gorilla and human. These findings and previous reports describing the transpositional activity of other Alu sequences within the human, gorilla, and chimpanzee lineages provide phylogenetic evidence for the existence of multiple Alu source genes. Sequences surrounding this particular Alu resemble known transcriptional control elements associated with RNA polymerase III, suggesting a mechanism by which cis-acting elements might be acquired upon retrotransposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00160256
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  • 14
    Digitale Medien
    Digitale Medien
    Molecular characteristics of the heterochromatic I elements from a reactive strain ofDrosophila melanogaster (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 424-431 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Drosophila melanogaster ; Evolution ; Hybrid dysgenesis ; I elements ; Transposons
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary There are two categories of strains inDrosophila melanogaster with respect to the I-R system of hybrid dysgenesis. The inducer strains contain particular transposable elements named I factors. They are not present in the strains of the other category called reactive (R) strains. Defective I elements are present in the pericentromeric regions of both categories of strains. This last subfamily of I sequences has not yet been described in detail and little is known about its origin. In this paper, we report that the defective I elements display an average of 94% of sequence identity with each other and with the transposable I factor. The results suggest that they cannot be the progenitors of the present day I factors, but that each of these two subfamilies started to evolve independently several million years ago. Furthermore, the sequence comparison of these I elements with an active I factor fromDrosophila teissieri provides useful information about when the deleted I elements became immobilized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02106056
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  • 15
    Digitale Medien
    Digitale Medien
    Interspecific comparison of the unusually repetitiveDrosophila locusmastermind (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 415-420 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Drosophila melanogaster ; Drosophila virilis ; mastermind ; Gene comparison ; Repetitive sequences ; Homopolymers ; Evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Themastermind gene ofDrosophila melanogaster encodes a novel, highly repetitive nuclear protein required for neural development. To identify functionally important regions we have initiated an interspecific comparison of the gene inDrosophila virilis. Mastermind transcription and genomic organization are similar in both species and sequence analysis reveals significant conservation in a major cluster of charged amino acids. In contrast, extensive variation is noted in homopolymer domains that immediately flank the acidic cluster. Distinct patterns of evolutionary change can be identified: the major difference between unique regions are occasional amino acid substitutions whereas the repetitive areas are characterized by numerous large in-frame insertions/deletions and a nearly threefold higher rate of amino acid replacement. Conservation of the acidic domain suggests that it has an important functional role whereas the hypervariable homopolymer regions appear to be under less selective constraints than adjacent unique areas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02101281
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  • 16
    Digitale Medien
    Digitale Medien
    Distribution of polymorphic gene duplication at theGpdh locus in natural populations ofDrosophila melanogaster (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 532-535 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Gene duplication ; Gpdh gene ; Polymorphism ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The glycerol-3-phosphate dehydrogenase (GPDH, E. C. 1.1.1.8) gene ofDrosophila melanogaster contains a tandem duplication of a 4.5-kb-long DNA fragment. Survey of theGpdh gene region by the Southern blot analysis revealed the following features of this gene duplication: (1) The duplication was not observed in chromosome lines that carryIn(2L)t, a cosmopolitan chromosomal inversion in this species. The duplication and the inversion are in linkage disequilibrium. (2) The duplication is polymorphic in the Japan and US natural populations examined. Its frequency is 0.26 on an average inIn(2L)t-free chromosomes. (3) Triplication is absent or has not become frequent in the populations surveyed. Possible evolutionary factors of this duplication polymorphism are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00556357
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  • 17
    Digitale Medien
    Digitale Medien
    An analysis of codon usage in mammals: Selection or mutation bias? (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 442-449 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Humans ; Mouse ; Rat ; Codon usage ; Mutation bias ; Selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A new statistical test has been developed to detect selection on silent sites. This test compares the codon usage within a gene and thus does not require knowledge of which genes are under the greatest selection, that there exist common trends in codon usage across genes, or that genes have the same mutation pattern. It also controls for mutational biases that might be introduced by the adjacent bases. The test was applied to 62 mammalian sequences, the significant codon usage biases were detected in all three species examined (humans, rats, and mice). However, these biases appear not to be the consequence of selection, but of the first base pair in the codon influencing the mutation pattern at the third position.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02103136
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  • 18
    Digitale Medien
    Digitale Medien
    The urate oxidase gene of Drosophila pseudoobscura and Drosophila melanogaster: Evolutionary changes of sequence and regulation (1992)
    Springer
    Journal of molecular evolution 34 (1992), S. 62-77 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Urate oxidase ; Drosophila pseudoobscura ; Drosophila melanogaster ; Nucleotide sequence ; Evolutionary comparison ; Gene regulation ; Malpighian tubules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The urate oxidase (UO) transcription unit of Drosophila pseudoobscura was cloned, sequenced, and compared to the UO transcription unit from Drosophila melanogaster. In both species the UO coding region is divided into two exons of approximately equal size. The deduced D. pseudoobscura and D. melanogaster UO peptides have 346 and 352 amino acid residues, respectively. The nucleotide sequences of the D. pseudoobscura and D. melanogaster UO protein-coding regions are 82.2% identical whereas the deduced amino acid sequences are 87.6% identical with 42 amino acid changes, 33 of which occur in the first exon. Although the UO gene is expressed exclusively within the cells of the Malpighian tubules in both of these species, the temporal patterns of UO gene activity during development are markedly different. UO enzyme activity, UO protein, and UO mRNA are found in the third instar larva and adult of D. melanogaster but only in the adult stage of D. pseudoobscura. The intronic sequences and the extragenic 5′ and 3′ flanking regions of the D. pseudoobscura and D. melanogaster UO genes are highly divergent with the exception of eight small islands of conserved sequence along 772 by 5′ of the UO protein-coding region. These islands of conserved sequence are possible UO cis-acting regulatory elements as they reside along the 5′ flanking DNA of the D. melanogaster UO gene that is capable of conferring a wild-type D. melanogaster pattern of UO regulation on a UO-lacZ fusion gene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00163853
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  • 19
    Digitale Medien
    Digitale Medien
    The evolution of two west African populations (1992)
    Springer
    Journal of molecular evolution 34 (1992), S. 336-344 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Humans ; Mitochondrial DNA ; Nuclear polymorphisms ; Heteroplasmy ; Genetic differentiation ; Sickle cell ; Rain forest refuges
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The identification of genetically coherent populations is essential for understanding human evolution. Among the culturally uniform ethnic groups of west Africa, there are two geographically distinct populations with high frequencies of sickle-cell hemoglobin (HbS). Although the HbS mutation in each group is found on distinguishable chromosomes 11, these populations have been assumed to be parts of a single population. Analysis of mitochondrial DNA (mtDNA) in these populations demonstrated that the two populations identified by alternative chromosomes 11 bearing HbS have distinct distributions of mitochondrial genotypes, i.e., they are maternally separate. These studies also showed that, contrary to expectation, the mtDNA of some individuals is heteroplasmic. For nuclear loci, a comparison of the frequency of alternative alleles established that these populations are genetically distinct. Both the mitochondrial and nuclear data indicate that these populations have been separate for approximately 50,000 years. Although HbS in the two populations is usually attributed to recent, independent mutations, the duration of the separation and the observed geographic distribution of the population allow for the possibility of an ancient origin of HbS. Assuming an ancient mutation and considering the known biogeography, we suggest that HbS protected selected populations from malaria in rain forest refuges during the most recent ice age.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00160241
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  • 20
    Digitale Medien
    Digitale Medien
    The product of the Drosophila melanogaster segment polarity gene armadillo is highly conserved in sequence and expression in the housefly Musca domestica (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 224-233 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Armadillo ; β-catenin ; Plakoglobin ; Drosophila melanogaster ; Musca domestica ; Nucleotide sequence ; Evolutionary comparison
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Segmental pattern in Drosophila melanogaster is set up via a set of cell-cell interactions mediated by the products of the segment polarity genes. Among these is the armadillo gene, whose product seems to be required for the reception of an intercellular signal encoded by the wingless gene. As part of our effort to relate the structure of the armadillo protein to its function within the cell, we have examined the evolutionary conservation of the armadillo gene during insect evolution. We have cloned the armadillo gene from the housefly, Musca domestica, which diverged from Drosophila 100 million years ago. The Musca protein is 97.5% identical to that in Drosophila, while the noncoding sequences have diverged extensively. This remarkable degree of conservation at the protein level is mirrored in the expression pattern of the armadillo protein. Antibodies against the Drosophila protein cross-react with a Musca protein of the appropriate size. We have also used these antibodies to show that the Musca armadillo protein has a pattern of expression in larval and adult tissues similar to that of Drosophila armadillo. We discuss the implications of conservation of structure and expression for the cellular role of the armadillo protein and its mammalian homologs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00160477
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  • 21
    Digitale Medien
    Digitale Medien
    Molecular evolution in theDrosophila yakuba period locus (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 389-401 
    Details
    ISSN: 1432-1432
    Schlagwort(e): period gene ; Nuclear vs mitochondrial silent substitution rates ; Amino acid replacement ; Drosophila yakuba ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Two nuclear genes fromDrosophila yakuba were cloned, the orthologue of theDrosophila melanogaster period (per) clock gene and the orthologue of an unnamedD. melanogaster gene adjacent toper, which encodes a 0.9-kb RNA transcript. The DNA and presumed protein sequences of both genes are presented and compared with their orthologues inD. melanogaster. Consistent with theper orthologues described in otherDrosophila species, some parts of theper gene have accumulated nonsynonymous substitutions at a much higher rate than others. This contrasts markedly with the evenly distributed amino acid replacements observed in the protein encoded by the adjacent gene. The level of synonymous and nonsynonymous substitutions betweenD. yakuba andD. melanogaster per were compared in small subsections across the gene. The results suggest that the divergence observed in the less well-conserved regions of theper protein is principally due to reduced selective constraint, although the limitations of the method used prevent positive selection acting upon a small proportion of sites being ruled out. The level of silent substituion observed in both of these nuclear genes is very similar to the level of silent substitution previously reported betweenD. melanogaster andD. yakuba mitochondrial genes, confirming several indirect studies, which have suggested that, in contrast to the case in mammals, silent sites are evolving at similar rates in mitochondrial and nuclear genes ofDrosophila.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02106054
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  • 22
    Digitale Medien
    Digitale Medien
    Dynamic equilibrium between insertion and excision of P elements in highly inbred lines from an M′ strain of Drosophila melanogaster (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 466-472 
    Details
    ISSN: 1432-1432
    Schlagwort(e): P element ; Transposition ; Copynumber regulation ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Six highly inbred lines of Drosophila melanogaster extracted from an M′ strain (in the P/M system of hybrid dysgenesis) were studied for the evolution of the number and chromosomal location of complete and defective P elements through generations 52–200. These lines possessed full-sized P elements but differed in their cytotype (M or P). Three lines with P cytotype and full-sized P elements at site 1A had a constant P copy number over generations with low rates of insertion and excision. Three lines with M cytotype and at least one full-sized P element accumulated P copies over the generations and reached a plateau near generation 196, at which rates of transposition and excision were equal to 1.2 × 10−3 to 3 × 10−3 events per element per generation. At that time these three lines still presented an M cytotype, produced transposase, and were able to regulate P copy number. The similarity at equilibrium between insertion and excision rates was exactly what was expected from theoretical models for a self-regulated element. The large number of generations necessary to attain the equilibrium in copy number indicates, however, that caution may be de rigueur when testing theoretical models of copy-number containment based on transposition and excision-rate comparison.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00173415
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  • 23
    Digitale Medien
    Digitale Medien
    P-elements are old components of the Scaptomyza pallida genome (1994)
    Springer
    Journal of molecular evolution 38 (1994), S. 232-240 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Drosophila melanogaster ; P-element evolution ; Scaptomyza pallida ; Immobile P-elements ; Pericentromeric heterochromatin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We report the cloning and analysis of a sample representative of all P-elements from Scaptomyza pallida. We have compared four independent stocks of this species, using Southern blot and in situ hybridization experiments to examine the number, structure, and distribution of P-elements. All four stocks give similar results: they contain about 15 P-elements including three to four full-length elements as well as shorter, deleted elements. All elements are divergent from one another and most of them appear to be immobile since they are located at identical positions in the genomes of independent stocks. These data indicate that P-elements are old components of the S. pallida genome. Moreover, the presence of P-sequences in species closely related to S. pallida suggests that they have had a long evolutionary history in the Scaptomyza genus. We have also found that most P-elements of S. pallida are located in the pericentromeric heterochromatin. This corroborates other studies which show that in the course of their evolution, transposable elements tend to accumulate into pericentromeric heterochromatin, where they become immobile and noncoding.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00176085
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  • 24
    Digitale Medien
    Digitale Medien
    Agaricus Bisporus: An assessment of its carcinogenic potency (1993)
    Springer
    Mycopathologia 124 (1993), S. 73-77 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Assessment ; Cancer ; Humans ; Hydrazines ; Mushroom
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract This assessment focuses on the concentrations of some chemicals present in theAgaricus bisporus mushroom, the cancer-inducing doses of these chemicals or mushroom used in the animal experiments, the total amounts of these chemicals or mushroom needed to induce cancer in these mice, and the estimated total amounts of these chemicals or mushroom needed to induce cancer in humans. By adding the estimated amounts of chemicals needed to induce cancer and by comparing it with the amount of raw mushroom needed to induce the same effect, it becomes obvious that we have accounted for less than 2% of the carcinogenic components of theAgaricus bisporus mushroom. Since some unavailable data handicapped this assessment, it should be regarded as tentative and subject to further adjustment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01103105
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  • 25
    Digitale Medien
    Digitale Medien
    Localization of cells capable of transdetermination in a specific region of the male foreleg disk ofDrosophila (1977)
    Springer
    Development genes and evolution 182 (1977), S. 69-74 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Male foreleg disk ; Capacity of transdetermination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848088
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  • 26
    Digitale Medien
    Digitale Medien
    Localized synthesis of specific proteins during oogenesis and early embryogenesis inDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 187 (1979), S. 151-165 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Oogenesis ; Embryogenesis ; Two-dimensional gels ; Protein synthesis ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848268
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  • 27
    Digitale Medien
    Digitale Medien
    Genes required for embryonic muscle development in Drosophila melanogaster A survey of the X chromosome (1993)
    Springer
    Development genes and evolution 202 (1993), S. 276-295 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Embryogenesis ; Muscle development ; Drosophila melanogaster ; Genetic analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have begun a genetic analysis to dissect the process of myogenesis by surveying the X chromosome of Drosophila melanogaster for mutations that affect embryonic muscle development. Using polarised light microscopy and antibody staining techniques we analysed embryos hemizygous for a series of 67 deletion mutations that together cover an estimated 85% of the X chromosome, or 16.5% of the genome. Whereas the mature wild type embryo has a regular array of contractile muscles that insert into the epidermis, 31 of the deletion mutants have defects in muscle pattern, contractility or both, that cannot be attributed simply to epidermal defects and identify functions required for wild type muscle development. We have defined mutant pattern phenotypes that can be described in terms of muscle absences, incomplete myoblast fusion, failure of attachment of the muscle to the epidermis or mispositioning of attachment sites. Thus muscle development can be mutationally disrupted in characteristic and interpretable ways. The areas of overlap of the 31 deletions define 19 regions of the X chromosome that include genes whose products are essential for various aspects of myogenesis. We conclude that our screen can usefully identify loci coding for gene products essential in muscle development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00363217
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  • 28
    Digitale Medien
    Digitale Medien
    Sequential emergence of the evenly spaced microchaetes on the notum of Drosophila (1993)
    Springer
    Development genes and evolution 203 (1993), S. 151-158 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Pattern formation ; Neurogenesis ; Peripheral nervous system ; Microchaetes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The small bristles (microchaetes) on the thorax of adult Drosophila are evenly spaced. We have analysed the development of this pattern using the enhancer trap line A101 where bacterial lacZ is expressed in the microchaete sensory mother cells (SMCs) and their progeny. We observed that the precursor cells appear in a stereotyped pattern of rows. Within each row, however, SMCs appear neither at a time nor in a restricted sequence: new SMCs are continuously intercalated between pre-existing SMCs until the distance between consecutive SMCs does not exceed a few cell diameters. In large individuals, additional SMCs may occasionally appear after the completion of the rows, in the largest empty spaces between the preexisting SMCs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00365054
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  • 29
    Digitale Medien
    Digitale Medien
    Clonal analysis in hybrids between Drosophila melanogaster and Drosophila simulans (1994)
    Springer
    Development genes and evolution 204 (1994), S. 112-117 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Drosophila simulans ; Hybrids ; Clonal analysis ; Lhr
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have analysed the viability of cellular clones induced by mitotic recombination in Drosophila melanogaster/D. simulans hybrid females during larval growth. These clones contain a portion of either melanogaster or simulans genomes in homozygosity. Analysis has been carried out for the X and the second chromosomes, as well as for the 3L chromosome arm. Clones were not found in certain structures, and in others they appeared in a very low frequency. Only in abdominal tergites was a significant number of clones observed, although their frequency was lower than in melanogaster abdomens. The bigger the portion of the genome that is homozygous, the less viable is the recombinant melano-gaster/simulans hybrid clone. The few clones that appeared may represent cases in which mitotic recombination took place in distal chromosome intervals, so that the clones contained a small portion of either melanogaster or simulans chromosomes in homozygosity. Moreover, Lhr, a gene of D. simulans that suppresses the lethality of male and female melanogaster/simulans hybrids, does not suppress the lethality of the recombinant melanogaster/simulans clones. Thus, it appears that there is not just a single gene, but at least one per tested chromosome arm (and maybe more) that cause hybrid lethality. Therefore, the two species, D. melanogaster and D. simulans, have diverged to such a degree that the absence of part of the genome of one species cannot be substituted by the corresponding part of the genome of the other, probably due to the formation of co-adapted gene complexes in both species following their divergent evolution after speciation. The disruption of those coadapted gene complexes would cause the lethality of the recombinant hybrid clones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00361105
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  • 30
    Digitale Medien
    Digitale Medien
    Genetic analysis of pattern-formation in the embryo ofDrosophila melanogaster (1977)
    Springer
    Development genes and evolution 183 (1977), S. 249-268 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Pattern-formation ; Embryogenesis ; Maternal-effect mutants ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00867325
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  • 31
    Digitale Medien
    Digitale Medien
    Suppression of abdominal legs inDrosophila melanogaster (1991)
    Springer
    Development genes and evolution 199 (1991), S. 449-457 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Bithorax complex ; Ultrabithorax ; abdominal-A
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Drosophila melanogaster normally have six thoracic legs and no abdominal legs. However, one or two legs often appear in the first abdominal segment ofbithoraxoid mutants. The extent to which these extra legs develop is determined both by thecis-regulatory action ofbithoraxoid lesions onUltrabithorax and by the number of copies of the adjacent homeotic geneabdominal-A. Thebithoraxoid region does notcis-regulateabdominal-A.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01705781
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  • 32
    Digitale Medien
    Digitale Medien
    Detection of clones in the nervous system ofDrosophila melanogaster (1977)
    Springer
    Development genes and evolution 183 (1977), S. 165-169 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Clones ; Nervous system ; Shibire ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848786
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  • 33
    Digitale Medien
    Digitale Medien
    Isozymic patterns and functional states of cell lines ofDrosophila melanogaster cultured in vitro. II (1976)
    Springer
    Development genes and evolution 180 (1976), S. 107-119 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Cell lines ; Isoenzymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848101
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  • 34
    Digitale Medien
    Digitale Medien
    A study of the female germ line in mosaics ofDrosophila (1978)
    Springer
    Development genes and evolution 184 (1978), S. 41-56 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Female germ line ; Mosaics ; Stem cell divisions ; Metafemale ; Sterility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848668
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  • 35
    Digitale Medien
    Digitale Medien
    Rudimentary mutants ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 187 (1979), S. 167-177 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Pyrimidine biosynthesis ; rudimentary mutants ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848269
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  • 36
    Digitale Medien
    Digitale Medien
    The eggshell ofDrosophlla melanogaster (1991)
    Springer
    Development genes and evolution 200 (1991), S. 95-103 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Eggshell ; Micropylar canal ; Microtubules ; Paracrystalline structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The micropylar apparatus (MA) inDrosophila melanogaster (Diptera: Drosophilidae) is a 25 μm long protrusion on the anterior pole of the eggshell, and it contains the 0.8 μm wide micropylar canal through which the spermatozoon penetrates the eggshell. The canal terminates in the paracrystalline structure thus forming the “pocket”. The MA is secreted during oogenesis by the micropylar follicle cells (border cells and peripheral cells). Morphogenesis of the micropylar canal starts before stage 11A, when two of the border cells form two thin extensions containing microfilaments and penetrate the paracrystalline structure. Microtubules found at the base of the extensions participate in the formation of two projections. Adjacent follicle cells secrete the chorionic part of the MA, whilst the two projections elongate and twist during stages 12 and 13. Microtubules run parallel to the long axis of the projections and probably are related to cellular elongation during the formation of the projections. The paracrystalline structure is composed of lamellae having a periodicity of about 50 nm, which is maintained possibly due to the lateral fibrils connecting the lamellae. These lamellae consist of small fragments secreted during stages 10–11 by the border cells. The paracrystalline structure and the spongy vitelline membrane are condensed after egg maturation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637189
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  • 37
    Digitale Medien
    Digitale Medien
    The effect of fat body on the differentiation in vitro of wing imaginal discs ofDrosophila melanogaster (1976)
    Springer
    Development genes and evolution 180 (1976), S. 73-77 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Ecdysones ; Imaginal discs ; Fat body ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848885
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  • 38
    Digitale Medien
    Digitale Medien
    Developmental potentials of the cells of the male foreleg disc ofDrosophila (1977)
    Springer
    Development genes and evolution 181 (1977), S. 309-320 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Drosophila melanogaster ; Male foreleg disc ; Pattern regulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00848058
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  • 39
    Digitale Medien
    Digitale Medien
    Microtubule inhibitors block the morphological changes induced inDrosophila blood cells by a parasitoid wasp factor (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 311-315 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Drosophila melanogaster ; Leptopilina heterotoma ; parasitoid ; blood cells ; vinblastine ; vincristine ; cytochalasin B ; cytoskeleton
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The shape change ofDrosophila melanogaster blood cells (lamellocytes) from discoidal to bipolar that is caused by a factor from the female parasitoidLeptopilina heterotoma is blocked by the tubulin inhibitors vinblastine and vincristine in vitro. The actin inhibitor, cytochalasin B, causes arborization ofDrosophila lamellocytes and acts synergistically with the wasp factor to alter lamellocyte morphology. Lamellocyte arborization induced by cytochalasin B is blocked by simultaneous treatment with vinblastine. These observations indicate that the changes in lamellocyte shape induced by both the wasp factor and cytochalasin B require microtubule assembly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01951775
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  • 40
    Digitale Medien
    Digitale Medien
    Proteins of the periodontium (1977)
    Springer
    Calcified tissue international 23 (1977), S. 39-44 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Dental cementum ; Collagen ; Protein ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([α1(I)]2α2) accounted for more than 90% of the organic matrix, while Type III collagen ([α1(III)]3) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from α1(I) and α2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012764
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  • 41
    Digitale Medien
    Digitale Medien
    Calcium deficiency, pregnancy, and lactation in rats (1977)
    Springer
    Calcified tissue international 23 (1977), S. 87-94 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; Osteoporosis ; Lactation ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The calcium homeostatic mechanism was challenged in adult female rats by feeding them a calcium-deficient diet containing oxalate, and by subjecting them to pregnancy and lactation. The regimen caused a substantial weight loss, especially in those animals which reared their young well. Severe hypocalcaemia was observed in the lactating rats. Serum-P was slightly elevated. The content of hydroxyproline in serum was considerably elevated, reflecting the degree of calcium deprivation. Serum proteins were least influenced. The calcium depriving regimen reduced the growth of long bones, but did not stop it. The ash content of the bones was considerably reduced, the degree of reduction depended on the degree of calcium deprivation. Ash as percentage of total bone organ was reduced, but not to the same extent as total ash. Analyses of different parts of femur showed that the proximal and distal parts had lost more bone mineral than the diaphyseal shaft. The ash content of cortical bone tissue from the femur was estimated by a volumetric method. No differences were observed between test groups and controls, indicating that no measurable amounts of bone mineral had been removed from the walls of the vascular canals or by osteocytic osteolysis. Planimetric determinations on cross sections from femora disclosed that a great amount of bone had been removed from the endosteal surface of the diaphysis, while the periosteal surface demonstrated reduced bone apposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012771
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  • 42
    Digitale Medien
    Digitale Medien
    The solar wind and human birth rate: A possible relationship due to magnetic disturbances (1990)
    Springer
    International journal of biometeorology 34 (1990), S. 42-48 
    Details
    ISSN: 1432-1254
    Schlagwort(e): Briths ; Humans ; Solar wind ; Geomagnetism ; Melatonin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Abstract Data obtained from the literature on the annual pattern of human conceptions and plasma melatonin at high latitudes indicated that simple annual rhythms do not exist. Instead, prominent semiannual rhythms are found, with equinoctial troughs and solsticial peaks. A prominent semiannual environmental event is the magnetic disturbance induced by the solar wind. The semiannual magnetic disturbances are worldwide, but most pronounced in the auroral zones where the corpuscular radiation enters the atmosphere. Magnetic indices that predominantly reflect these events were obtained from the literature and correlated with the melatonin and conception data. Significant and inverse correlations were found for Inuit conceptions and the melatonin data. The correlations obtained for 48 contiguous states of the United States indicated that only the extreme northern states exhibited this relationship. These data were compared with a previous correlational study in the United States which established that sunshine was correlated with conceptions in the middle latitude and southern states. An hypothesis of dual control by electromagnetic and magnetic energies is proposed: melatonin is a progonadal hormone in humans controlled by both factors, depending on their relative strength. Other studies are reviewed regarding the possible factors involved in determining the annual pattern of human conceptions. Demographic studies of geographic variation in temporal patterns of conceptions, with particular regard to variations of the magnetic fields on the earth's surface, may provide some insight into the efficacy of these different factors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01045819
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  • 43
    Digitale Medien
    Digitale Medien
    Male-male interactions and mating kinetics inDrosophila (1990)
    Springer
    Behavior genetics 20 (1990), S. 405-421 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; Drosophila simulans ; host-parasitoid models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract Male-male interaction (K) has been estimated from data on the attrition rate of virgin females per minute in a study of the mating kinetics inDrosophila. K is expressed as the time males expend on other males relative to that expended while searching for, courling, and copulating with females. The value of K in these studies ranged from 0 (approximately) to. 695; it was affected both by strain (sepia orebony D. melanogaster and wild-typeD. simulans) and by size of the mating chamber. Host-parasitoid models of ecologists appear to be appropriate for examining mating kinetics inDrosophila.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01065566
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  • 44
    Digitale Medien
    Digitale Medien
    Drosophila courtship song cycles in normal andperiod mutant males revisited (1990)
    Springer
    Behavior genetics 20 (1990), S. 617-644 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; reproductive behavior ; pulse songs ; interpulse intervals ; per s , perL1, andper 01 rhythm mutants ; Fourier analyses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract Courtship songs of normal males and those expressing short-period, long-period, and arrhythmic mutations at theperiod (per) locus ofDrosophila melanogaster have been reanalyzed for rhythmic components, using spectral treatments of the fluctuating rates of tone pulse production that occur during courtship. It was concluded, as in previous studies, that such songs are strongly rhythmic, except for courtships performed byper 01 males. Songs produced by males expressing this and otherper alleles were compared to computer-generated “random” ones. Interpulse interval variations influenced byper 01 and songs simulated to be arrhythmic both were found to be associated with cryptic rhythmicities; several such period values, extracted by the spectral analyses, defined very short cycle durations. We discuss the implications of these findings and of some recently reported results that have challenged the existence of rhythmicity inDrosophila songs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01065875
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  • 45
    Digitale Medien
    Digitale Medien
    Nutritional control of xanthine dehydrogenase. II. Effects on xanthine dehydrogenase and aldehyde oxidase of culturing wild-type and mutant Drosophila on different levels of molybdenum (1975)
    Springer
    Biochemical genetics 13 (1975), S. 53-64 
    Details
    ISSN: 1573-4927
    Schlagwort(e): aldehyde oxidase ; xanthine dehydrogenase ; Drosophila melanogaster ; molybdenum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00486006
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  • 46
    Digitale Medien
    Digitale Medien
    The size of poly(A)-containing RNAs in Drosophila melanogaster embryos (1976)
    Springer
    Biochemical genetics 14 (1976), S. 357-371 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; poly(A)-containing RNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484774
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  • 47
    Digitale Medien
    Digitale Medien
    Partial purification and properties of guanosine triphosphate cyclohydrolase from Drosophila melanogaster (1976)
    Springer
    Biochemical genetics 14 (1976), S. 259-270 
    Details
    ISSN: 1573-4927
    Schlagwort(e): GTP cyclohydrolase ; Drosophila melanogaster ; pteridines ; dihydroneopterin triphosphate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484765
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  • 48
    Digitale Medien
    Digitale Medien
    The suppressor of forked mutation in Drosophila melanogaster: Interactions with the lozenge gene (1976)
    Springer
    Biochemical genetics 14 (1976), S. 611-617 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; phenol oxidases ; spectrophotometry ; electrophoresis ; suppression ; ribosomal proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00485839
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  • 49
    Digitale Medien
    Digitale Medien
    Selection against homozygotes in the ADH polymorphic system of Drosophila melanogaster associated with the lethal factor l(2) Stm (1977)
    Springer
    Biochemical genetics 15 (1977), S. 93-100 
    Details
    ISSN: 1573-4927
    Schlagwort(e): alcohol dehydrogenase (ADH) ; genetic polymorphism ; selection ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484551
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  • 50
    Digitale Medien
    Digitale Medien
    Origin of α-glycerophosphate dehydrogenase isozymes in Drosophila melanogaster and their functional relationship in the α-glycerophosphate cycle (1977)
    Springer
    Biochemical genetics 15 (1977), S. 235-251 
    Details
    ISSN: 1573-4927
    Schlagwort(e): l-glycerol-3-phosphate dehydrogenase (α-GPDH) ; isozymes ; development ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484456
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  • 51
    Digitale Medien
    Digitale Medien
    Isolation and genetic characterization of alcohol dehydrogenase thermostability variants occurring in natural populations of Drosophila melanogaster (1977)
    Springer
    Biochemical genetics 15 (1977), S. 971-988 
    Details
    ISSN: 1573-4927
    Schlagwort(e): allozymes ; thermostability ; alcohol dehydrogenase ; Drosophila melanogaster ; natural populations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00483992
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  • 52
    Digitale Medien
    Digitale Medien
    Control of drosopterin synthesis in Drosophila melanogaster: Mutants showing an altered pattern of GTP cyclohydrolase activity during development (1978)
    Springer
    Biochemical genetics 16 (1978), S. 13-26 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; GTP cyclohydrolase ; development ; pteridine biosynthesis ; mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484381
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  • 53
    Digitale Medien
    Digitale Medien
    A genetic and developmental analysis of an acid deoxyribonuclease in Drosophila melanogaster (1978)
    Springer
    Biochemical genetics 16 (1978), S. 1113-1134 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; isozymes ; position effect ; segmental aneuploidy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484532
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  • 54
    Digitale Medien
    Digitale Medien
    Variation in amount of enzyme protein in natural populations (1978)
    Springer
    Biochemical genetics 16 (1978), S. 159-170 
    Details
    ISSN: 1573-4927
    Schlagwort(e): alcohol dehydrogenase ; allozyme properties and amounts ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484075
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  • 55
    Digitale Medien
    Digitale Medien
    Alcohol metabolism in Drosophila melanogaster: Uselessness of the most active aldehyde oxidase produced by the Aldox locus (1978)
    Springer
    Biochemical genetics 16 (1978), S. 203-211 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; alcohol tolerance ; alcohol utilization ; alcohol dehydrogenase ; aldehyde oxidase ; allozymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484078
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  • 56
    Digitale Medien
    Digitale Medien
    A simple approach for discovering common nonelectrophoretic enzyme variability: A heat denaturation study in Drosophila melanogaster (1978)
    Springer
    Biochemical genetics 16 (1978), S. 299-305 
    Details
    ISSN: 1573-4927
    Schlagwort(e): nonelectrophoretic structural variability ; Drosophila melanogaster ; phosphoglucomutase ; genetic polymorphism ; heat denaturation study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484086
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  • 57
    Digitale Medien
    Digitale Medien
    Developmental changes of sepiapterin synthase activity associated with a variegated purple gene in Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 197-206 
    Details
    ISSN: 1573-4927
    Schlagwort(e): sepiapterin synthase ; variegation ; purple ; Drosophila melanogaster ; pteridine eye pigments ; drosopterin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484485
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  • 58
    Digitale Medien
    Digitale Medien
    Polymorphism at the G6pd and 6Pgd loci in Drosophila melanogaster. III. Developmental and biochemical aspects (1979)
    Springer
    Biochemical genetics 17 (1979), S. 1131-1144 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; enzyme polymorphism ; G6PD ; 6PGD ; enzyme activity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00504350
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  • 59
    Digitale Medien
    Digitale Medien
    Investigations on the PGM (phosphoglucomutase) polymorphism by isoelectric focusing inDrosophila melanogaster (1990)
    Springer
    Biochemical genetics 28 (1990), S. 247-255 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; phosphoglucomutase ; nonelectrophoretic variability ; isoelectric focusing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Pgm allele frequencies of 383 individuals were determined in a sample ofDrosophila melanogaster from three laboratory Sardinian populations, using the techniques of standard electrophoresis, heat denaturation, and isoelectric focusing. The analysis of the progeny obtained from informative crosses showed that the isoelectric focusing patterns segregate in a Mendelian way. ThePgm 1.00 andPgm 0.70 electrophoretic alleles displayed different isoelectric points, whereas thePgm 1.00,tr andPgm 1.00,ts isoelectrophoretic alleles could not be differentiated when tested by isoelectric focusing. Moreover, thePgm 0.70,ts allele was split into two classes, with isoelectric points ofpH 6.4 andpH 6.6.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554082
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  • 60
    Digitale Medien
    Digitale Medien
    Transport defects as the physiological basis for eye color mutants of Drosophila melanogaster (1975)
    Springer
    Biochemical genetics 13 (1975), S. 603-613 
    Details
    ISSN: 1573-4927
    Schlagwort(e): transport mutants ; eye color mutants ; kynurenine ; Drosophila melanogaster ; Malpighian tubules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484918
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  • 61
    Digitale Medien
    Digitale Medien
    Correlation of guanosine triphosphate cyclohydrolase activity and the synthesis of pterins in Drosophila melanogaster (1976)
    Springer
    Biochemical genetics 14 (1976), S. 271-280 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; GTP cyclohydrolase ; pteridine biosynthesis ; development ; mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484766
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  • 62
    Digitale Medien
    Digitale Medien
    Genetics and physiological expression of β-hydroxy acid dehydrogenase in Drosophila (1978)
    Springer
    Biochemical genetics 16 (1978), S. 333-342 
    Details
    ISSN: 1573-4927
    Schlagwort(e): β-hydroxy acid dehydrogenase ; chromosome ; dosage compensation ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484089
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  • 63
    Digitale Medien
    Digitale Medien
    Dietary rescue of a lethal “null” activity allele of 6-phosphogluconate dehydrogenase in Drosophila melanogaster (1978)
    Springer
    Biochemical genetics 16 (1978), S. 469-475 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; 6-phosphogluconate dehydrogenase ; Pgd n lethal alleles ; rescue by dietary supplements ; hexose monophosphate shunt
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The genetic rescue of Pgd n lethal alleles, accomplished by combining them with mutations lacking glucose-6-phosphate dehydrogenase activity, has led to the hypothesis that Pgd n lethality may be due to the accumulation of 6-phosphogluconate. In this article we report the rescue of Pgd n /Y males by dietary supplements (fructose and linolenate) designed to minimize 6-phosphogluconate production.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484212
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  • 64
    Digitale Medien
    Digitale Medien
    Biochemical properties of esterase 6 in Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 1-22 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; esterase 6 ; allozymes ; biochemical properties
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Biochemical properties of esterase 6 in Drosophila melanogaster were investigated using partially purified preparations from three genotypes, 1/1, 1/2, and 2/2. The molecular weight of the enzyme is estimated to be about 90,000, and treatment with sodium dodecylsulfate cleaves the enzyme into four units with a molecular weight of about 22,000. The activity toward 28 naturally occurring esters was assayed and shown to vary considerably with substrate, the 1/1 preparation having in general higher activity than 1/2 and 2/2, which were very similar. Heat sensitivity, the effect of metal ions, and the effects of the presence or absence of an end product were also studied. The differences demonstrated between allozymes would allow considerable scope, under appropriate conditions, for differential selection to operate between genotypes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484470
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  • 65
    Digitale Medien
    Digitale Medien
    Properties of the two common electrophoretic variants of phosphoglucomutase in Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 825-836 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; phosphoglucomutase ; polymorphism ; enzyme kinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Phosphoglucomutase (PGM) of adult stage in Drosophila melanogaster has been characterized by gel filtration, ion-exchange chromatography, and isoelectric focusing. The two common electrophoretic variants, PGMA and PGMB, differ with respect to their kinetic and stability parameters. PGMA is more thermostable than PGMB but shows the same pH optimum, equal dependence on Mg2+, and identical molecular weight. There is no significant kinetic difference between the two allozymes at the optimum pH value, but at pH 6.0 the K m value for glucose-1,6-diphosphate of PGMB is significantly higher than that of PGMA. This difference might explain the observed selective advantage of the Pgm A allele in population studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00504306
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  • 66
    Digitale Medien
    Digitale Medien
    The gene coding for glutamate dehydrogenase inDrosophila melanogaster (1990)
    Springer
    Biochemical genetics 28 (1990), S. 337-346 
    Details
    ISSN: 1573-4927
    Schlagwort(e): glutamate dehydrogenase ; Drosophila melanogaster ; gene expression ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract We have isolated theDrosophila melanogaster locus coding forl-glutamate dehydrogenase (EC 1.4.1.3) by virtue of its similarity to the corresponding human gene. There is only one copy of this gene in the fruit fly genome, located on the right arm of chromosome 3 (95D1-4). The transcript includes at least one large intron and matures to a ∼2.4-kb-long polyadenylated RNA whose expression is under developmental control.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554064
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  • 67
    Digitale Medien
    Digitale Medien
    The fatty acid constitution and ordering state of membranes in dominant temperature-sensitive lethal mutation and wild-typeDrosophila melanogaster larvae (1990)
    Springer
    Biochemical genetics 28 (1990), S. 233-246 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; membranes ; dominant temperature sensitive ; wild type ; fatty acids ; spin label
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The ordering state and changes in fatty acid composition of microsomal (MS) and mitochondrial (MC) membranes of two dominant temperature-sensitive (DTS) lethal mutations and the wild-type Oregon-R strain larvae ofDrosophila melanogaster have been studied at 18 and 29°C and after temperature-shift experiments. The membranes of wild-type larvae have a stable ordering state, with “S” values between 0.6 (18°C) and 0.5 (29°C) in both membranes which remained unchanged in shift experiments, although the ratios of saturated/unsaturated fatty acids were changed as expected. The stronglyDTS mutation1(2)10 DTS forms very rigid membranes at the restrictive temperature (29°C) which cannot be normalized after shift down, while shift up or development at the permissive temperature results in normal ordering state. This mutant is less able to adjust MS and MC fatty acid composition in response to the growth temperature than the wild type. The less temperature-sensitive1(2)2 DTS allele occupies an intermediate state between Oregon-R and1(2)10 DTS in both respects. We assume and the genetical data suggest that the DTS mutant gene product is in competition with the wild-type product, resulting in a membrane structure which is not able to accommodate to the restrictive temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554081
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  • 68
    Digitale Medien
    Digitale Medien
    Biological role of alcohol dehydrogenase in the tolerance of Drosophila melanogaster to aliphatic alcohols: Utilization of an ADH-null mutant (1976)
    Springer
    Biochemical genetics 14 (1976), S. 989-997 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; alcohol dehydrogenase ; enzyme biological activity ; toxicity of alcohols
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The toxicity of the first eight primary alcohols and of four secondary alcohols was compared in a wild-type strain (having active ADH) and an ADH-negative mutant. Differences between lc 50 measured in the two strains allowed an evaluation of the biological activity of the enzyme. In vitro, ADH is mainly active on secondary alcohols, while in vivo its main role is the detoxification and metabolism of ethanol. These observations suggest that originally ADH was involved in unknown metabolic pathways and that its utilization in ethanol metabolism could be a recent event.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00485131
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  • 69
    Digitale Medien
    Digitale Medien
    Preparation of specific antisera to Drosophila acid phosphatase without rigorous protein purification (1976)
    Springer
    Biochemical genetics 14 (1976), S. 237-243 
    Details
    ISSN: 1573-4927
    Schlagwort(e): null alleles ; antibody purification ; Drosophila melanogaster ; immunological methods
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Extracts from an acid phosphatase CRM− null mutant of Drosophila melanogaster were used to eliminate contaminating antibodies in a nonspecific preparation of anti-acid phosphatase serum. This method of producing specific antisera makes unnecessary the rigorous purification of an antigen prior to immunization attempts in those cases where CRM− null mutants of the antigen are available. Antisera so prepared could be used for a wide variety of purposes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484763
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  • 70
    Digitale Medien
    Digitale Medien
    Association and the Adh locus with a lethal factor (l(2) Stm) in Drosophila melanogaster (1976)
    Springer
    Biochemical genetics 14 (1976), S. 299-308 
    Details
    ISSN: 1573-4927
    Schlagwort(e): allozymes ; alcohol dehydrogenase ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Keeping Drosophila cultures at 28 C results in elimination of all minor multiple ADH bands, thought to be due to conformational change. Thus in diploid and triploid adults heterozygous for the Adh F and Adh Salleles, relative staining intensities are found for the three bands which were in conformity with the assumption that both alleles are equally expressed. Among all polymorphic strains derived from natural Central European and Mediterranean populations, the strain +Tüb is unique in that its Adh Fallele is closely linked to a new recessive lethal factor, named 1(2)Stm. All Adh F 1/AdhF 1 pupae are unable to emerge, and die. The lethal effect is obvious 50 hr earlier by retarded eye, bristle, and body wall pigmentation. Although all pupae of the phenotype F die, Adh F allele frequency scarcely seems to be lowered in this natural population.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484769
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  • 71
    Digitale Medien
    Digitale Medien
    Further evidence of thermostability variation within electrophoretic mobility classes of enzymes (1976)
    Springer
    Biochemical genetics 14 (1976), S. 383-387 
    Details
    ISSN: 1573-4927
    Schlagwort(e): allozymes ; thermostability ; alcohol dehydrogenase ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Two Drosophila melanogaster strains, each heterozygous for “fast” and “slow” alleles at the Adh locus, and each having balanced second chromosomes, were found to differ in the apparent thermostability of the slow allozyme. The two strains were crossed, and F1heterozygotes were separated on the basis of the origin of the slow allele. After electrophoresis, the cellulose acetate strips were treated 1 1/2 min at 35 C. The putatively more sensitive allozyme showed a strikingly greater response to heat. These findings further support the conclusion that electrophoretically cryptic allelic differences exist which are expressed in thermostability differences. Further application of this approach has revealed one similar sensitive slow allozyme and three cases of a relatively resistant fast ADH allozyme in wild-caught flies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484776
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  • 72
    Digitale Medien
    Digitale Medien
    Demonstration of 6-phosphogluconolactonase activity in Drosophila melanogaster using a null allele of 6-phosphogluconate dehydrogenase (1978)
    Springer
    Biochemical genetics 16 (1978), S. 1023-1029 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; 6-phosphogluconolactonase ; hexose monophosphate shunt ; Pgd n Zw n mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Using a double mutant strain, Pgd n Zw n , we have developed an assay for 6-phosphogluconolactonase activity and have demonstrated its occurrence in adult Drosophila melanogaster.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00483752
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  • 73
    Digitale Medien
    Digitale Medien
    Enumeration of Drosophila form II DNA-dependent RNA polymerase initiation sites on Drosophila DNA (1979)
    Springer
    Biochemical genetics 17 (1979), S. 97-104 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; form II RNA polymerase initiation sites ; chromomeres
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The in vitro incorporation of γ-32P-labeled nucleoside triphosphates into RNA by Drosophila melanogaster form II RNA polymerase from template sites which afford protection from the initiation inhibitor, polyriboinosinic acid (poly [I]), is used as a method for enumerating a specific class of transcription initiation sites on D. melanogaster DNA. Such sites number about 4000 per haploid genome for D. melanogaster. This value is in good agreement with the number of functional genetic units in the D. melanogaster genome as determined by classical cytogenetics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484476
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  • 74
    Digitale Medien
    Digitale Medien
    Purine transport by Malpighian tubules of pteridine-deficient eye color mutants of Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 565-573 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; Malpighian tubules ; purine transport ; eye color mutants ; riboflavin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Uptakes of guanine into Malpighian tubules of wild-type Drosophila and the eye color mutants white (w), brown (bw), and pink-peach (p p) have been compared. Tubules for each of these mutants are unable to concentrate guanine intracellularly. The transport of xanthine and riboflavin is also deficient in w tubules. The transport of guanosine, adenine, hypoxanthine, and guanosine monophosphate is similar in wild-type and white Malpighian tubules. These data and other information about these mutants make it likely that these pteridine-deficient eye color mutants do not produce pigments because of the inability to transport a pteridine precursor. This view supports the hypothesis that mutants which lack both pteridine and ommochromes do so because precursors to both classes of pigments share a common transport system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00498891
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  • 75
    Digitale Medien
    Digitale Medien
    Modelling the constancy of X (1994)
    Springer
    Astrophysics and space science 216 (1994), S. 153-154 
    Details
    ISSN: 1572-946X
    Schlagwort(e): Chemistry ; Molecular Hydrogen ; Cloud Models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Observations of the CO J=1-0 line are commonly used as a tracer for molecular material in clouds. The ratio of the H2 column density to the integrated intensity of this line,X, is often taken to be constant, despite theoretical and observational uncertainty. We have tried to identify how this ratio depends on cloud parameters, testing a simple theoretical argument suggesting its invariance with respect to density. The apparent constancy can be understood if clouds are clumpy on scales of Av ≈ 1-2 mag.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00982486
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  • 76
    Digitale Medien
    Digitale Medien
    Chromosomal analysis of gregarious oviposition byDrosophila melanogaster (1994)
    Springer
    Behavior genetics 24 (1994), S. 187-190 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Gregarious oviposition ; chromosomal assays ; Drosophila melanogaster ; polygenic ; behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract The contribution of different chromosomes to variation in the gregarious oviposition behavior of Drosophila melanogaster females was elucidate by a chromosome substitution analysis. Lines of D. melanogaster previously selected for more than 190 generations for high or low levels of gregarious oviposition were crossed to a tester strain having genetically marked inversion-containing chromosomes. Genes influencing gregarious oviposition behavior are distributed over chromosome II and III. Interactions among the chromosomes were negligible as measured in this experiment. The differences in the gregarious oviposition performance of these two selected lines is due mainly to the accumulation of factors for high gregarious oviposition on chromosomes II and factors for low gregarious oviposition on chromosome III.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01067823
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  • 77
    Digitale Medien
    Digitale Medien
    Biometrical analysis of larval digging behavior inDrosophila melanogaster (1994)
    Springer
    Behavior genetics 24 (1994), S. 427-432 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; larval development ; digging behavior ; diallel crosses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract Digging behavior of D. melanogaster larvae increases as larval development proceeds. Diallel crosses were made to analyze genetically digging behavior at 72 and 108 h of larval age. Additive and dominance variation was found, dominance being principally to dig. Dominance to dig is higher at 108 than 72 h of development; additivity does not substantially change between these two larval ages. At 72 h of larval age, depending on the cross, I found (i) dominance to dig, (ii) dominance to nondig, (iii) overdominance to dig, and (iv) no dominance to dig. At 108 h of larval development I detected (i) dominance to dig and (ii) overdominance to dig. Thus, diversity of response in the F1 was greater at 72 than 108 h of larval development. These age-related changes in larval digging behavior of D. melanogaster seem to reflect epigenetic changes in the patterns of gene expressions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01076178
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  • 78
    Digitale Medien
    Digitale Medien
    Genetics of factors affecting the life history ofDrosophila melanogaster. IV. Cytoplasmic/maternal factors affect egg insertion behavior (1990)
    Springer
    Behavior genetics 20 (1990), S. 675-686 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; genetic analysis ; oviposition behavior ; egg insertion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract The genetic basis of insertion behavior of laboratory strains ofDrosophila melanogaster was examined. Reciprocal crosses among five strains revealed a significant effect of interaction between cytoplasmic/maternal factors and the chromosomal genotype in determining the insertion tendency, thus complicating the characterization of the dominant/recessive nature of the insertion genes. The majority of heterozygous combinations demonstrated dominance or partial dominance for the higher insertion tendency over low insertion, while a few combinations produced results to the contrary. These could be due to a more complex genetic basis of insertion behavior than a simple dominant/recessive relationship or else to the cytoplasmic/maternal-chromosome interactions. Examination of the effects of each chromosome revealed the greates contributions to insertion tendency from the second and third chromosomes, with a significant effect of interaction or nonadditivity of the insertion genes in these two chromosomes in the genotypes tested. The X and fourth chromosomes appear to contribute a small effect in some strains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01065878
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  • 79
    Digitale Medien
    Digitale Medien
    Genetic variation for oviposition behavior inDrosophila melanogaster. II. Oviposition preferences and differential survival (1990)
    Springer
    Behavior genetics 20 (1990), S. 661-673 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; oviposition ; alcohol dehydrogenase ; fitness
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract Several behavioral traits connected with oviposition were studied inDrosophila melanogaster strains which had been kept on regular and ethanol-supplemented food. All strains preferred food with a low agar content for oviposition, though this tendency was more pronounced in an ethanol-adapted strain. Oviposition on regular and ethanol-supplemented food was tested both under choice and no-choice conditions. Though dependent on the alcohol dehydrogenase genotype, adapted strains in general preferred ethanol food, while control strains preferred regular food. There was a strong tendency for oviposition on the vertical sides, when food blocks were offered. This tendency was more pronounced in the ethanol adapted strains. For egg insertion (for which the genetic basis was analyzed in the preceding paper; Kamping and van Delden, 1990), it was shown that inserted eggs laid on ethanol food hatched more often than noninserted eggs. The adaptive significance of the genetic differences in oviposition behavioral traits is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01065877
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  • 80
    Digitale Medien
    Digitale Medien
    Variants of α-glycerophosphate dehydrogenase in diploids and triploids of Drosophila melanogaster (1975)
    Springer
    Biochemical genetics 13 (1975), S. 263-271 
    Details
    ISSN: 1573-4927
    Schlagwort(e): allozymes ; α-glycerophosphate dehydrogenase ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract On the basis of band staining intensities in electrophoretic runs of single flies homozygous and heterozygous for two alleles at the autosomal locus for GPDH, F allele activity is believed to be 8% lower than S allele activity. Indeed, the intensity distribution in the patterns of FSS and FFS triploid females shows that both are not equally expressed. On a per fly or live weight basis, females with two and three doses of the Gpdh gene show bands with equal staining intensity, thus exhibiting a dosage effect when GPDH activity is estimated on a per cell basis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00486021
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  • 81
    Digitale Medien
    Digitale Medien
    Variation between electrophoretically identical alleles at the alcohol dehydrogenase locus in Drosophila melanogaster (1975)
    Springer
    Biochemical genetics 13 (1975), S. 721-731 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; enzyme variation ; alcohol dehydrogenase ; electrophoretically identical alleles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A new variant of alcohol dehydrogenase (ADH 71k) was found in a laboratory stock of Drosophila melanogaster. ADH in this stock had the same electrophoretic mobility as the F variant both on acrylamide and on agar. Activity levels were similar to the levels in F flies at temperatures between 15 and 25 C. But while ADH F enzyme is inactivated rapidly at 40 C, ADH 71k is still active. Also, ADH S is not inactivated at this temperature, but has a far lower activity per fly than ADH 71k. Genetic analysis showed that the new variant is an allele of the Adh locus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484929
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  • 82
    Digitale Medien
    Digitale Medien
    Isozyme variability in species of the genus Drosophila. VIII. The alcohol dehydrogenase polymorphism in north carolina populations of D. melanogaster (1976)
    Springer
    Biochemical genetics 14 (1976), S. 47-58 
    Details
    ISSN: 1573-4927
    Schlagwort(e): electrophoresis ; alcohol dehydrogenase ; Drosophila melanogaster ; isozymes ; genetic variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Adult Drosophila melanogaster flies collected from populations broadly dispersed over ecological and geographic strata of North Carolina, and over a period of 4 years, were analyzed for alcohol dehydrogenase phenotypes by gel electrophoresis. Gene frequencies in spring-summer-fall field collections were remarkably stable over all strata. Two winter collections exhibited contrasting gene frequency changes. In one case the results are interpreted in terms of long-distance migration from Florida, while the other is explicable by assignment of a causal role to environmental factors which accompany the winter season.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484872
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  • 83
    Digitale Medien
    Digitale Medien
    Heat stability studies at the α-glycerophosphate dehydrogenase locus in populations of Drosophila melanogaster (1978)
    Springer
    Biochemical genetics 16 (1978), S. 769-775 
    Details
    ISSN: 1573-4927
    Schlagwort(e): hidden variation ; α-GPDH ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The level of hidden variation in populations of Drosophila melanogaster at the Gpdh + locus was determined by thermal stability studies of the protein. The results indicate a lack of variation using these methods both in and between the two common electrophoretic variants. It is suggested that α-GPDH is conserved in primary structure, which may be related to its critical role in flight muscle metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484734
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  • 84
    Digitale Medien
    Digitale Medien
    Mutagenesis at the cinnabar locus in Drosophila melanogaster (1978)
    Springer
    Biochemical genetics 16 (1978), S. 855-865 
    Details
    ISSN: 1573-4927
    Schlagwort(e): kynurenine hydroxylase ; cinnabar locus ; EMS mutagenesis ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A study was undertaken to isolate mutations affecting the temporal appearance of kynurenine hydroxylase in Drosophila melanogaster. Such mutations, lacking or having reduced enzyme activity at the larval or pupal stage only, could represent changes in regulatory functions. Mutagenesis was carried out using EMS. Potential mutations were isolated from mass F1 cultures. The screening of large numbers of individuals was made possible by the use of the mutant red, which allowed visual classification for the presence or absence of the enzyme at both stages. From a series of six mutagenesis experiments 111,561 chromosomes were tested, and 122 phenotypically mutant F1 individuals were found. From these, 38 inheritable mutations were isolated which, by phenotypic observation, lacked or had reduced enzyme activity at the larval and pupal stages. Assay of enzyme activity levels in several of the mutants confirmed the phenotypic data. All of the 27 mutations that could be tested further are recessive and behave as cinnabar alleles. Complementation tests were performed between these 27 mutant stocks, and no complementation in the production of eye color has been seen between the mutants examined. When extended collection periods were used, a significantly higher percentage of inheritable mutations was isolated from the first 3 days of the screen. Over 80% of the F1 phenotypic mutants could be classified as mosaics, which indicates that cinnabar can be autonomous under certain conditions. The failure to isolate mutations in possible regulatory function is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00483738
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  • 85
    Digitale Medien
    Digitale Medien
    Isolation and biochemical analysis of a temperature-sensitive scarlet eye color mutant of Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 149-158 
    Details
    ISSN: 1573-4927
    Schlagwort(e): xanthommatin synthesis ; scarlet mutants ; Drosophila melanogaster ; temperature-sensitive mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Six new EMS-induced scarlet mutants were selected. Four of these were partially pigmented, with xanthommatin levels ranging from 12% to 45% of normal. In one (st 754ts), pigment production was temperature sensitive; the level of xanthommatin changed from less than 10% of normal at 29 C to more than 70% at 18 C. In all of the new mutants tested, the level of early pupal 3-hydroxykynurenine was as low as low as that in st 1. Thus reduced larval accumulation of this metabolite also appears to be a characteristic feature of scarlet mutants. Temperature-pulse and temperature-shift experiments were carried out with st 754ts to determine the temperature-sensitive period for the scarlet gene during development. The major sensitive period commenced prior to the onset of pigmentation and was over before adult emergence. Thus the initiation of xanthommatin synthesis is not brought about by the activation of the scarlet gene. In similar experiments carried out with a temperature-sensitive white mutant (w bl), a similar temperature-sensitive period was obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00484480
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  • 86
    Digitale Medien
    Digitale Medien
    Partial purification and some properties of biopterin synthase and dihydropterin oxidase from Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 351-369 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; biopterin synthesis ; oxidation of dihydropterins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract An enzyme which has been named “biopterin synthase” has been discovered in Drosophila melanogaster. This enzyme, which has been purified 200-fold from extracts of Drosophila, catalyzes the conversion of sepiapterin to dihydrobiopterin, or oxidized sepiapterin to biopterin. The K m values for the two substrates are 63 µm for sepiapterin and 10 µm for oxidized sepiapterin. NADPH is required in this enzymatic reaction. An analysis of enzyme activity during development in Drosophila indicates a correlation between enzyme activity and biopterin content at various development stages. Another enzyme, called “dihydropterin oxidase,” was also discovered and partially purified. This enzyme catalyzes the oxidation of dihydropterin compounds to the corresponding pterin compounds. For example, sepiapterin (a dihydropterin) is oxidized to oxidized sepiapterin in the presence of this enzyme. The only dihydropterin that has been tested that is not a substrate for this enzyme is dihydroneopterin triphosphate, the compound thought to be a precursor for all naturally occurring pterins and dihydropterins. Since the action of dihydropterin oxidase is reduced significantly when the concentration of oxygen is very low, it is likely that this enzyme uses molecular oxygen as the oxidizing agent during the oxidation of dihydropterins. Neither NAD+ or NADP+ is required. In the presence of the two enzymes dihydropterin oxidase and biopterin synthase, sepiapterin is converted to biopterin. However, in the presence of biopterin synthase alone, sepiapterin is converted to dihydrobiopterin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00498975
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  • 87
    Digitale Medien
    Digitale Medien
    The gene coding for glutamate dehydrogenase inDrosophila melanogaster (1990)
    Springer
    Biochemical genetics 28 (1990), S. 337-346 
    Details
    ISSN: 1573-4927
    Schlagwort(e): glutamate dehydrogenase ; Drosophila melanogaster ; gene expression ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract We have isolated theDrosophila melanogaster locus coding forl-glutamate dehydrogenase (EC 1.4.1.3) by virtue of its similarity to the corresponding human gene. There is only one copy of this gene in the fruit fly genome, located on the right arm of chromosome 3 (95D1-4). The transcript includes at least one large intron and matures to a ∼2.4-kb-long polyadenylated RNA whose expression is under developmental control.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02401423
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  • 88
    Digitale Medien
    Digitale Medien
    The fatty acid constitution and ordering state of membranes in dominant temperature-sensitive lethal mutation and wild-typeDrosophila melanogaster larvae (1990)
    Springer
    Biochemical genetics 28 (1990), S. 233-246 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; membranes ; dominant temperature sensitive ; wild type ; fatty acids ; spin label
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The ordering state and changes in fatty acid composition of microsomal (MS) and mitochondrial (MC) membranes of two dominant temperature-sensitive (DTS) lethal mutations and the wild-type Oregon-R strain larvae ofDrosophila melanogaster have been studied at 18 and 29°C and after temperature-shift experiments. The membranes of wild-type larvae have a stable ordering state, with “S” values between 0.6 (18°C) and 0.5 (29°C) in both membranes which remained unchanged in shift experiments, although the ratios of saturated/unsaturated fatty acids were changed as expected. The stronglyDTS mutation1(2)10 DTS forms very rigid membranes at the restrictive temperature (29°C) which cannot be normalized after shift down, while shift up or development at the permissive temperature results in normal ordering state. This mutant is less able to adjust MS and MC fatty acid composition in response to the growth temperature than the wild type. The less temperature-sensitive1(2)2 DTS allele occupies an intermediate state between Oregon-R and1(2)10 DTS in both respects. We assume and the genetical data suggest that the DTS mutant gene product is in competition with the wild-type product, resulting in a membrane structure which is not able to accommodate to the restrictive temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02401414
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  • 89
    Digitale Medien
    Digitale Medien
    Investigations on the PGM (phosphoglucomutase) polymorphism by isoelectric focusing inDrosophila melanogaster (1990)
    Springer
    Biochemical genetics 28 (1990), S. 247-255 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; phosphoglucomutase ; nonelectrophoretic variability ; isoelectric focusing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Pgm allele frequencies of 383 individuals were determined in a sample ofDrosophila melanogaster from three laboratory Sardinian populations, using the techniques of standard electrophoresis, heat denaturation, and isoelectric focusing. The analysis of the progeny obtained from informative crosses showed that the isoelectric focusing patterns segregate in a Mendelian way. ThePgm 1.00 andPgm 0.70 electrophoretic alleles displayed different isoelectric points, whereas thePgm 1.00,tr andPgm 1.00,ts isoelectrophoretic alleles could not be differentiated when tested by isoelectric focusing. Moreover, thePgm 0.70,ts allele was split into two classes, with isoelectric points ofpH 6.4 andpH 6.6.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02401415
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  • 90
    Digitale Medien
    Digitale Medien
    Tolerance to 1-pentene-3-ol and to 1-pentene-3-one in relation to alcohol dehydrogenase (ADH) and aldo keto reductase (AKR) activities inDrosophila melanogaster (1990)
    Springer
    Biochemical genetics 28 (1990), S. 513-522 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; 1-pentene-3-ol ; 1-pentene-3-one ; alcohol dehydrogenase ; aldo-keto reductase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The detoxification of 1-pentene-3-ol (pentenol) and 1-pentene-3-one (pentenone) byDrosophila melanogaster adult flies has been studied in two homozygous lines for theAdh F andAdh S alleles (LRC lines), in their respective lines selected for tolerance to ethanol (LRSe lines) and in a homozygous strain for theAdh n4 null allele. For each line, the genotype and sex LDs50 of both compounds were estimated. Then, in order to explain the differences in LD50, both alcohol dehydrogenase (ADH) and aldo keto reductase (AKR) activities were assayed. In addition, the effects of pentenone on AKR activity were also studied. Our results show that ADH-positive flies exhibit a much higher sensitivity to pentenol than ADH-null flies. However, both ADH-positive and ADH-null flies show a similar tolerance to pentenone. Our results show that flies selected for improving tolerance to ethanol also have increased tolerance to pentenol (FF andSS flies) and pentenone (SS flies). However, this improved ability to tolerate pentenol and/or pentenone cannot be explained by changes in ADH or AKR activities. On the other hand, we have observed a beneficial effect of pentenol, but not of pentenone, in n4 flies. We also show that AKR activity is not modified by the administration of pentenone. These results suggest that, in the absence of ADH activity, pentenol may be transformed into a compound that is less toxic than pentenone and that pentenone itself might also be transformed into a less toxic compound.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554379
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  • 91
    Digitale Medien
    Digitale Medien
    Bidirectional selection for female receptivity inDrosophila melanogaster (1993)
    Springer
    Behavior genetics 23 (1993), S. 77-83 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; artificial selection ; female receptivity ; hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract A wild population ofDrosophila melanogaster was subjected to selection for high and low female receptivity. Selection was only applied in females on the basis of the mating times observed in a 30-min period. We applied a selection paradigm that allowed us to conclude that females unmated after 30 min correspond to the truncated upper tail of the distribution underlying mating times. Selection was successful, with mean mating times of about 5 min for the high lines, 35 min for the low lines, and 12 min for the control. Receptivity of the selection lines remained steady after 42 generations of relaxed selection, suggesting a lack of natural selection on receptivity in laboratory conditions. We also found a clear relationship between high or low receptivity and high or low frequency of hybridization withD. simulans males, emphasizing the role of female receptivity in maintaining isolation with its sibling speciesD. simulans.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01067556
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  • 92
    Digitale Medien
    Digitale Medien
    Male mating speed inDrosophila melanogaster: Differences in genetic architecture and in relative performance according to female genotype (1993)
    Springer
    Behavior genetics 23 (1993), S. 349-358 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Mating speed ; diallel analysis ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract From a critical review of the literature on mating speed inDrosophila the importance of fast mating in male fitness is questioned. The genetic architecture of male mating speed (MMS) has been evaluated inD. melanogaster through a populational analysis and a full 5×5 diallel cross between inbred lines. The results emphasize the fundamental role of the female genotype in both the absolute and the relative MMS performances. Somewhat different genetic architectures for MMS are revealed according to the female used in the tests. It is suggested that different parts of the complex genetic system involved in the male's “behavioral sexual phenotype” are relevant depending on the female's characteristics, thus causing the heterogeneity in the MMS genetic architecture. An overall picture reveals a genetic system characterized by additivity, dominance for fast mating, and no influence of the X chromosome. There results do not support strong natural selection favoring fast mating inDrosophila males.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01067436
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  • 93
    Digitale Medien
    Digitale Medien
    Genetic variation for oviposition behavior inDrosophila melanogaster. I. Quantitative genetic analysis of insertion behavior (1990)
    Springer
    Behavior genetics 20 (1990), S. 645-659 
    Details
    ISSN: 1573-3297
    Schlagwort(e): Drosophila melanogaster ; egg insertion behavior ; bidirectional selection ; heritability ; genetic variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract The genetic basis of egg insertion behavior was analyzed in twoDrosophila melanogaster strains (N and E strain), which were homozygous for theSlow allele of the alcohol dehydrogenase locus. The E strain had been selected for increased tolerance to ethanol. This study originated from the observation that nearly all of the eggs laid by females of the E strain were inserted, while in the control strain (N strain) which was kept on regular food, considerable variation for egg insertion occurred. Crosses between the E and the N strains were made, and quantitative genetic tests were performed. It was shown that the inheritance of egg insertion is polygenic, some of the genes are probably sex linked, and in-laying is partly dominant over on-laying. The heritability of the trait, derived from mother-daughter regression analysis, was .59±.18. The repeatability was high. Bidirectional selection in the E strain was unsuccessful, but an asymmetrical response to selection was obtained in the N strain and in lines derived from crosses between the N and the E strains. Selection for in-laying was more successful than for on-laying. The realized heritability in the former lines was .35±.10.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01065876
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  • 94
    Digitale Medien
    Digitale Medien
    Dipeptidase-C inDrosophila melanogaster: Genetic, ontogenetic, and tissue-specific variation (1992)
    Springer
    Biochemical genetics 30 (1992), S. 603-624 
    Details
    ISSN: 1573-4927
    Schlagwort(e): dipeptidases ; Drosophila melanogaster ; ontogenetic variation ; tissue distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Dip-A, Dip-B, andDip-C constitute structural genes for three peptidic enzymes inDrosophila melanogaster distinct from the leucine aminopeptidases. Their ontogenetic and tissue distributions of activities suggest the involvement of these enzymes in a general metabolic role, such as the regulation of amino acid and oligopeptide pools to make amino acids available for protein synthesis. Screening of chromosome substitution isogenic lines for DIP-C activity indicated that, like DIP-A and DIP-B, unlinked activity modifiers exist forDip-C. The developmental profiles of dipeptidase activities are very similar, except in the pupal stage, during which DIP-C activity is markedly low compared to the other two enzymes. Intercorrelations of dipeptidase activities vary ontogenetically, which is consistent with the need for coordinate expression of these enzymes during certain developmental stages. Tissue-specific expressions of dipeptidases in larvae and adults are also similar, although the relative levels of DIP-A activity differ from those of DIP-B and DIP-C in certain organs and body parts. Some of the differences among chromosome substitution lines for dipeptidase activities appear to be systemic, while others are developmental stage-specific and tissue-specific. Second- and third-chromosome variants for DIP-C activity differed in their tissue distribution. This is consistent with the presence of temporal and spatial variants in natural populations for otherDrosophila enzymes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00553804
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  • 95
    Digitale Medien
    Digitale Medien
    Dipeptidase-C inDrosophila melanogaster: Genetic, ontogenetic, and tissue-specific variation (1992)
    Springer
    Biochemical genetics 30 (1992), S. 603-624 
    Details
    ISSN: 1573-4927
    Schlagwort(e): dipeptidases ; Drosophila melanogaster ; ontogenetic variation ; tissue distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Dip-A, Dip-B, andDip-C constitute structural genes for three peptidic enzymes inDrosophila melanogaster distinct from the leucine aminopeptidases. Their ontogenetic and tissue distributions of activities suggest the involvement of these enzymes in a general metabolic role, such as the regulation of amino acid and oligopeptide pools to make amino acids available for protein synthesis. Screening of chromosome substitution isogenic lines for DIP-C activity indicated that, like DIP-A and DIP-B, unlinked activity modifiers exist forDip-C. The developmental profiles of dipeptidase activities are very similar, except in the pupal stage, during which DIP-C activity is markedly low compared to the other two enzymes. Intercorrelations of dipeptidase activities vary ontogenetically, which is consistent with the need for coordinate expression of these enzymes during certain developmental stages. Tissue-specific expressions of dipeptidases in larvae and adults are also similar, although the relative levels of DIP-A activity differ from those of DIP-B and DIP-C in certain organs and body parts. Some of the differences among chromosome substitution lines for dipeptidase activities appear to be systemic, while others are developmental stage-specific and tissue-specific. Second- and third-chromosome variants for DIP-C activity differed in their tissue distribution. This is consistent with the presence of temporal and spatial variants in natural populations for otherDrosophila enzymes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02399810
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  • 96
    Digitale Medien
    Digitale Medien
    Genetic differentiation ofDrosophila melanogaster populations as assessed by two-dimensional electrophoresis (1991)
    Springer
    Biochemical genetics 29 (1991), S. 389-401 
    Details
    ISSN: 1573-4927
    Schlagwort(e): two-dimensional electrophoresis ; Drosophila melanogaster ; intraspecific phylogeny ; genetic variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Seven populations ofDrosophila melanogaster, representing a worldwide distribution, were compared using two-dimensional protein gel electrophoresis. A total of 611 protein spots was scored, which probably represent a sample of over 500 loci that were surveyed. Of the protein spots scored, 521 spots were found to be invariant, but another 90 spots were found to be variable among the populations. Of these variable protein spots, 12 were found to be present in only one population. All the populations, except one, had at least one protein spot restricted to itself. However, the Japanese population had by far the most, with five protein spots restricted to this one population, which has been observed in previous studies of private alleles in oriental populations. The mean genetic similarity (F) found among the seven populations was 0.965, with a range of between 0.956 and 0.977. This is similar to previous reports of lower variation found in population genetic surveys using two-dimensional electrophoresis. It was found that the historical relationships among these populations was somewhat congruent with the geographic distribution of the populations, but as in previous studies, it was not exactly coincident.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554145
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  • 97
    Digitale Medien
    Digitale Medien
    Genetic control and expression of the major ejaculatory bulb protein (PEB-me) inDrosophila melanogaster (1991)
    Springer
    Biochemical genetics 29 (1991), S. 215-239 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; tissue-specific protein ; sex-specific protein ; genetic mapping ; genetic polymorphism ; reproduction-associated protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract PEB-me is a predominant protein of matureDrosophila melanogaster ejaculatory bulbs. It is resolved into four or five closely spaced subfractions (apparent molecular weight 35–39 kD) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Four electrophoretic variants of PEB-me differing in apparent molecular weight by 200–800 daltons were found. These appear to be controlled by four alleles of a gene (peb) located by recombination and deletion mapping to the 60F1-2 region of chromosome 2. A minor ejaculatory bulb protein of ca. 80 kD (hPEB) was found to be immunochemically related to PEB and possibly encoded bypeb. PEB is not detected by immunoblotting techniques in virgin females, in male tissues other than the ejaculatory bulb, or during developmental stages preceding the formation of this organ. The results of transplantations of genital imaginal discs and of immature ejaculatory bulbs between two strains having different PEB alleles suggest that the ejaculatory bulb is the site of PEB synthesis. In flies mutant fortra, tra-2, dsx, orix, tissue specificity of PEB localization is retained and the protein is found whenever the ejaculatory bulb is formed, regardless of the chromosomal sex of the fly. The protein is transferred into the female genital duct during mating, where it can be detected for up to 12 hr. Possible functions of PEB inDrosophila reproduction are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00590103
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Biochemical and physiological studies of soluble esterases fromDrosophila melanogaster (1991)
    Springer
    Biochemical genetics 29 (1991), S. 365-388 
    Details
    ISSN: 1573-4927
    Schlagwort(e): Drosophila melanogaster ; esterases ; biochemical properties ; expression pattern
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Twenty-two soluble esterases have been identified inD. melanogaster by combining the techniques of native polyacrylamide gel electrophoresis and isoelectric focusing. The sensitivity of each isozyme to three types of inhibitors (organophosphates, eserine sulfate, and sulfydryl reagents) identified 10 as carboxylesterases, 6 as cholinesterases, and 3 as acetylesterases. Three isozymes could not be classified and no arylesterases were identified. The carboxyl- and cholinesterases could each be further divided into two subclasses on the basis of inhibition by organophosphates and sulfhydryl reagents, respectively. Cholineand acetylesterases have characteristic substrate preferences but both subclasses of carboxylesterases are heterogeneous in substrate utilization. Subclass 2 carboxylesterases exhibit diverse temporal expression patterns, with subclass 1 carboxylesterases generally found in larvae and subclass 1 cholinesterases and acetylesterases more characteristic of pupae and adults. Tissues showing the greatest number of isozymes are larval body wall (eight) and digestive tract (six in larvae, six in adults). Carboxylesterases are distributed across a wide range of tissues, but subclass 1 cholinesterases are generally associated with neural or neurosecretory tissues and subclass 2 cholinesterases with digestive tissues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554144
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Uptake and incorporation in pteridines of externally supplied GTP in normal and pigment-deficient eyes ofDrosophila melanogaster (1992)
    Springer
    Biochemical genetics 30 (1992), S. 61-75 
    Details
    ISSN: 1573-4927
    Schlagwort(e): white gene ; Drosophila melanogaster ; eye pigment synthesis ; GTP cyclohydrolase activity ; drosopterin synthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Some aspects of the synthesis of drosopterins in the eyes ofDrosophila melanogaster have been studied in flies with different levels ofwhite gene expression. The activity of GTP cyclohydrolase was found to differ between wild-type and yellow-eyed mutantsin vivo but notin vitro. To elucidate the uptake of substrate, we measured the removal of labeled GTP from the incubation medium by excised pupal eyes and followed the subsequent fate of this label. It was found that GTP was dephosphorylated to guanosine extracellularly before label was taken up by the eye tissue. The uptake was much lower in yellow and white eyes than in wild-type eyes, and in the latter, a considerable part of the label was present in pteridine compounds. The strain differences in the uptake of label seem to be due to different rates of intracellular utilization of guanine derivatives in pteridine synthesis. We suggest that this is caused by a hampered transport of precursor (possibly GTP) in white andzeste eyes through the membrane of red pigment granules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00554428
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    A cluster of esterase genes on chromosome 3R ofDrosophila melanogaster includes homologues of esterase genes conferring insecticide resistance inLucilia cuprina (1994)
    Springer
    Biochemical genetics 32 (1994), S. 39-62 
    Details
    ISSN: 1573-4927
    Schlagwort(e): esterases ; Drosophila melanogaster ; organophosphate resistance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract We identify an esterase isozyme inDrosophila melanogaster, EST 23, which shares biochemical, physiological, and genetic properties with esterase E3, which is involved in resistance to organophosphate insecticides inLucilia cuprina. Like E3, theD. melanogaster EST 23 is a membrane-bound α-esterase which migrates slowly toward the anode at pH 6.8. Both enzymes have similar preferences for substrates with shorter acid side chain lengths. Furthermore, on the basis of their high sensitivity to inhibition by paraoxon and their insensitivity to inhibition by eserine sulfate, both enzymes were classified as subclass I carboxylesterases. The activity of each enzyme peaks early in development and, again, in the adult stage. Both enzymes are found in the male reproductive system and larval and adult digestive tissues, the latter being consistent with a role for these enzymes in organophosphate resistance. Fine structure deficiency mapping localizedEst 23 to cytological region 84D3 to E1-2 on the right arm of chromosome 3. Moreover, we show that the genes encoding three other esterase phenotypes also map to the same region; these phenotypes involve allozymic differences in EST 9 (formerly EST C), ali-esterase activity, defined by the hydrolysis of methyl butyrate, and malathion carboxylesterase activity, defined by hydrolysis of the organophosphate malathion. This cluster corresponds closely to that encompassing E3 and malathion carboxylesterase on chromosome 4 inL. cuprina, the homologue of chromosome 3R inD. melanogaster.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00557238
    Standort Signatur Erwartet Verfügbarkeit
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