The effects of delayed mating on components of fitness, life span, and the geotactic behavior of Drosophila melanogaster selected for a postponed senescence.
Item
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Title
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The effects of delayed mating on components of fitness, life span, and the geotactic behavior of Drosophila melanogaster selected for a postponed senescence.
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Identifier
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AAI9009741
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identifier
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9009741
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Creator
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Hoffmann, Robert Nicholas.
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Contributor
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Adviser: Joseph Grossfield
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Date
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1989
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, General | Biology, Genetics | Biology, Zoology
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Abstract
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Components of fitness were studied in two strains of Drosophila melanogaster selected for late reproduction and two control strains. All descended from the same ancestral strain.;Two replicates of virgin flies (30 males and 30 females) of equal age (1, 2, 4, 7, 14, 21, 28, and 42 days) were tested for: the number of fertile matings, mean fecundity, total fecundity, total fertility, and mean fertility. Data was for 1,920 females for three days post 24 mating opportunity.;Fecundity data support the "antagonistic pleiotropy" hypothesis. Young shorter-lived females had significantly higher mean fecundities than young longer-lived females. Conversely, at a late age, longer-lived females had significantly higher mean fecundities relative to shorter-lived females. Control strain fertility was significantly greater than that of selected strain. Fertility data was consistent with the hypotheses of "mutation accumulation" and "age of onset" genes.;Additional data for offspring from "old" (42 day-old) virgin females mated to "young" (7 day-old) virgin males and vice versa is consistent with the hypotheses of "age of onset" genes and the "cost of reproduction.".;Survivorship distributions were obtained for populations of virgin flies, both sexes, for the four strains. Males from long-lived strains had survivorships that were very significantly greater than long-lived females and both sexes of control strains. Survivorship of long lived strains was consistent with the "rate of living" and "cost of reproduction" hypotheses.;Age-dependent behavioral loss of negative geotactic response and survivorships of virgin flies, both sexes of the four strains, were studied in the dark on an inclined plane at 9 angles, 3 presentation orders. Randomized tests at 11 ages, for groups of 20, showed no strain or sex differences at the two youngest ages. Both sexes of long lived populations, had greater responses at a late age. Relative mean negative geotactic responses were consistent with the "mutation accumulation" and "rate of living" hypotheses of aging.;It is concluded that fecundity, fertility, fertile mating in females, and the negative geotactic responses of these strains are under the control of different sets of genes with different patterns of action over time in both sexes of the selected and the control strains.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
