ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Non-linear selection response in Drosophila: a strategy for testing the rare-alleles model of quantitative genetic variability (1997)
    Springer
    Genetica 99 (1997), S. 59-66 
    Details
    ISSN: 1573-6857
    Keywords: artificial selection ; Drosophila ; genetic variation ; non-linear response ; rare alleles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Quantitative genetic theory predicts that variation due to rare alleles at many loci will generate a transient acceleration in the response to directional selection. We have tested this prediction by constructing experimental lines of Drosophila melanogaster that carry positively selected ethanol resistance alleles at low frequencies, and then subjecting the lines to directional selection for ethanol resistance. Approximately 468,000 files were subjected to artificial selection over 30 generations. The predicted non-linear selection responses were observed in all experimental lines and replicates, on three genetic backgrounds. In contrast, un-selected controls and lines carrying random alleles at low frequencies on the same genetic backgrounds exhibited linear selection responses. These results demonstrate that non-linearities due to rare alleles are detectable and repeatable, provided that experiments are done on a sufficiently large scale. The results suggest that it may be possible to test for rare-alleles as a component of naturally occurring genetic variation by careful examination of selection response curves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018390313864
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Density, mortality, and the narrow view (1995)
    Springer
    Genetica 96 (1995), S. 187-189 
    Details
    ISSN: 1573-6857
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01439571
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Chaperoning extended life (1997)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 390 (1997), S. 30-30 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The capacity to moderate internal and external stress is arguably the central function regulating senescence in whole-animal ageing. During ageing, molecular chaperones such as heat-shock proteins are thought to combat stress-related senescent dysfunction. In transgenic Drosophila melanogaster, ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/36237
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Peeking under QTL peaks (2003)
    [s.l.] : Nature Publishing Group
    Nature genetics 34 (2003), S. 358-359 
    Details
    ISSN: 1546-1718
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] Much progress has been made in the last decade toward understanding the genes and pathways that control lifespan in yeast, nematodes and fruitflies. Mutant screens have uncovered a variety of mutations that extend lifespan in laboratory populations of model organisms, but it is not known whether ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/ng0803-358
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Genetic analysis of extended lifespan in Drosophila melanogaster III. On the relationship between artificially selected and wild stocks (2000)
    Springer
    Genetica 109 (2000), S. 245-253 
    Details
    ISSN: 1573-6857
    Keywords: artificial selection ; Drosophila ; lifespan ; mortality ; paraquat ; DDT ; recovery hypothesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Adult lifespans, age‐specific survival, age‐specific mortality, survival times on paraquat, and survival times on DDT were assayed in seven lines of Drosophila melanogaster, including two genetically heterogeneous wild lines recently collected from nature, and three inbred and recombinant inbred lines derived from an artificial selection experiment for increased lifespan. Survival on paraquat is positively correlated with adult lifespan. DDT resistance is uncorrelated with either paraquat resistance or lifespan. The wild lines are unexceptional with respect to average lifespan, paraquat resistance, age‐specific survivorship, and leveling off of mortality rates at advanced ages, but have high levels of DDT resistance. Cluster analysis groups the wild lines with three unselected laboratory stocks in one cluster, while two long‐lived elite recombinant inbred lines form a second cluster. Long‐lived laboratory‐adapted lines are quantitatively differentiated from the wild stocks, both with respect to average adult lifespans and resistance to an oxidizing agent. We reject the ‘recovery’ hypothesis, which proposes that Drosophila artificially selected for long life have phenotypes that merely recover the wild state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017569318401
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Genetic analysis of extended life span in Drosophila melanogaster II. Replication of the backcross test and molecular characterization of the N14 Locus (1998)
    Springer
    Genetica 104 (1998), S. 33-39 
    Details
    ISSN: 1573-6857
    Keywords: life span ; artificial selection ; quantitative trait locus ; polygenic characters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We are interested in localizing chromosomal regions that extend life span in Drosophila. Using stocks artificially selected for long life by Luckinbill and his colleagues, we have identified marker loci that are highly divergent in allelic frequencies between replicated long-lived lines and controls (Curtsinger et al., 1998). Several of the most divergent loci have been found to be associated with effects on life span in segregating backcross populations. Here we report an independent replication of the backcross test for the N14 marker locus, previously reported to extend male life spans by 12 days. The life span effect successfully replicates in males. N14 accounts for 30% of the total selection response in males. Life span extension occurs by a decrease in age-specific mortality rates at all ages, and is not attributable to modification of the slope of the age-specific mortality curve. The effect in females is small or nonexistent. Sequencing of the N14 locus shows that it is non-coding and not obviously regulatory, suggesting that the phenotypic effect arises from linkage disequilibrium with another locus or loci that directly affect life span. N14 DNA hybridizes to 63F/64A on the left arm of chromosome 3. The location is consistent with previous whole-chromosome substitution studies, and suggests new candidate genes for life span extension in Drosophila, including ras2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003420625925
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Genetic analysis of extended life span in Drosophila melanogaster I. RAPD screen for genetic divergence between selected and control lines (1998)
    Springer
    Genetica 104 (1998), S. 21-32 
    Details
    ISSN: 1573-6857
    Keywords: life span ; longevity ; QTL ; artificial selection ; genetic drift
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using lines selected for long life by Luckinbill and his co-workers, we screened two selected and two control lines for allelic frequency differences at 1200 randomly chosen RAPD marker loci. Twenty-three marker loci showed frequency differences in excess of 80%, and five were greater than 90%. Age-specific effects of the five most differentiated loci were estimated by collecting complete survival data in segregating backcross populations. Alleles at four of the five marker loci were associated with significant extension of life span in males, while two marker loci had significant effects in females. Eighty percent of the total selection response in males can be explained by the identified QTL's, under the assumption of additivity. The N14+ marker allele accounted for a 12-day life span extension in males, but had little effect in females. Both sex-limited and sex-shared effects were observed. Analysis of age-specific mortality rates suggests that life span extension occurs by a combination of genetic factors that moderate both the level of mortality and the rate at which mortality increases with age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003442619700
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Relationship between α-glycerophosphate dehydrogenase activity and metabolic rate during flight in Drosophila melanogaster (1986)
    Springer
    Biochemical genetics 24 (1986), S. 245-257 
    Details
    ISSN: 1573-4927
    Keywords: flight metabolism ; Drosophila ; αGPDH ; Kacser-Burns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Measurements of wing-beat frequency (WBF) have been used to characterize flight muscle metabolic rate in Drosophila melanogaster during tethered flight. Progeny of crosses between 17 X-chromosome substitution lines and three null-activity stocks have been studied in order to determine the effect on flight metabolism of sharply reduced activity of α-glycerophosphate dehydrogenase (αGPDH). It was found that flies with an approximate 50% reduction in αGPDH activity have a metabolic rate that is, in most cases, indistinguishable from that of wild-type flies and, in the most extreme cases, reduced by only 4%. These results demonstrate that αGpdh is not a “major gene” for flight metabolism, in the quantitative genetic sense of the term. These results are in agreement with the Kacser and Burns (1973, 1979, 1981) theory of flux, which postulates that the activity of an enzyme embedded in a multienzyme pathway can sometimes vary from wild-type to very low levels (perhaps 5–10% wild type) with no significant effect on flux through the total pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502792
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Genotype and anesthetic determine mate choice in drosophila melanogaster (1990)
    Springer
    Behavior genetics 20 (1990), S. 73-79 
    Details
    ISSN: 1573-3297
    Keywords: Drosophila ; mating behavior ; mate choice ; anesthesia ; etherization ; genetic variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Genetic differences that influence mating preferences were studied in genetically defined lines ofDrosophila melanogaster. Initial results suggested substantial differences between two types of females with respect to the types of male preferred as mates, but further experimentation showed that the mating patterns were conditional on the mode of anethesia (CO2 versus ether). In a statistical test of independence, the major determinant of mating choice in these experiments was due to an interaction effect between genotypes and mode of anesthesia. The observations might be explained by the differential sensitivity of male genotypes to ether. Etherization at emergence has lasting effects on mating behavior; it alters not only the latency and frequency of mating 4 days later, but also the pattern of matings observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01070742
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Density and age-specific mortality (1995)
    Springer
    Genetica 96 (1995), S. 179-182 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; aging ; density ; mortality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Age-specific mortality rates decelerate at older ages in laboratory populations in the MedflyCeratitis capitata. This has been interpreted by Careyet al. (1992) to reflect a slowing of the aging process, but might also be explained by declining adult density. Here it is argued that the density explanation, as presented by Graves and Mueller (1993), is unpersuasive for several reasons: extrapolations fromDrosophila to Medflies are unjustified; the range of densities they studied is 2–120 times higher than that used in other studies; they ignore data on Medflies held in isolation, which rule out density effects; their own data suggest that initial cohort density has no effect on mortality rates at older ages, which is the relevant part of the life cycle; their experiment is too small to provide accurate estimates of mortality; new Medfly experiments executed at multiple densities show decelerating and then declining mortality rates at advanced ages for all densities. WhenDrosophila survivorship experiments are done on a sufficiently large scale they also show a deceleration of mortality at older ages that is not attributable to density effects. The deceleration of mortality rates is most likely a real facet of aging, and will have to be taken into consideration in any synthesis of the genetics and evolution of aging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01439569
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...