Population Genetics of Transposable Element Copy Number in Drosophila

University Of California-Davis, Davis CA

Investigators

Abstract

Transposable elements (TEs) are tiny organisms, with genome sizes varying from hundreds to thousands of nucleotides, that live within a cell nucleus and survive by spreading their progeny on host chromosomes. TEs have multiple negative effects on host's performance: they cause mutations and induce deletions and duplications. Hosts with too many TEs are eliminated since they are unfit. What regulates TE activity? To answer this question, we will identify genes controlling transpositions of a model TE - copia, and their mutant variants that permit copia transpositions. We hypothesize that mutant host genes are present in natural Drosophila melanogaster populations. To test this hypothesis and determine the frequency of mutant alleles, we will study transpositions in 150 lines of flies. In flies with broken TE control, TE numbers explode. How likely, fast, and dramatic could TE explosions be? Is there enough variation in host genes controlling transposition rate to rapidly suppress exploding TEs? Our data will help answer these, and other important questions having a broad impact on conservation biology programs, and on breeding programs aimed at improving cultured stocks. Further, our research will provide new training experiences for undergraduate, graduate students and a postdoc in molecular population genetics and evolution.