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      https://www.ias.ac.in/article/fulltext/jgen/083/03/0265-0277

    • Keywords

       

      line-cross analysis; epistasis; dominance; adaptation; experimental evolution; reverse evolution; life-history evolution; quantitative genetics; Drosophila

    • Abstract

       

      What are the genetics of phenotypes other than fitness, in outbred populations? To answer this question, the quantitative-genetic basis of divergence was characterized for outbredDrosophila melanogaster populations that had previously undergone selection to enhance characters related to fitness. Line-cross analysis using first-generation and second-generation hybrids from reciprocal crosses was conducted for two types of cross, each replicated fivefold. One type of cross was between representatives of the ancestral population, a set of five populations maintained for several hundred generations on a two-week discrete-generation life cycle and a set of five populations adapted to starvation stress. The other type of cross was between the same set of ancestral-representative populations and another set of five populations selected for accelerated development from egg to egg. Developmental time from egg to eclosion, starvation resistance, dry body weight and fecundity at day 14 from egg were fit to regression models estimating single-locus additive and dominant effects, maternal and paternal effects, and digenic additive and dominance epistatic effects. Additive genetic variation explained most of the differences between populations, with additive maternal and cytoplasmic effects also commonly found. Both within-locus and between-locus dominance effects were inferred in some cases, as well as one instance of additive epistasis. Some of these effects may have been caused by linkage disequilibrium. We conclude with a brief discussion concerning the relationship of the genetics of population differentiation to adaptation.

    • Author Affiliations

       

      Henrique Teotónio1 2 Margarida Matos3 Michael R. Rose1

      1. Department of Ecology and Evolutionary Biology, University of California, Irvine, CA - 92697-2525, USA
      2. Centro de Biologia do Desenvolvimento, Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, Oeiras - 2780-156, Portugal
      3. Centro de Biologia Ambiental, Dep. Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande Lisboa - 1749-016, Portugal
    • Dates

       
  • Journal of Genetics | News

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