Population Genetics of Transposable Element Copy Number in Drosophila

转座元件(TES)是一种微小的生物体，基因组大小从数百到数千个核苷酸不等，它们生活在细胞核内，通过在宿主染色体上传播后代来生存。TES对宿主的表现有多种负面影响：它们会导致突变，并导致缺失和复制。拥有太多TE的主机将被淘汰，因为他们不适合。是什么规范了TE的活动？为了回答这个问题，我们将识别控制模型TE-Copia的转座的基因，以及允许Copia转座的突变变体。我们假设在自然黑腹果蝇种群中存在突变的宿主基因。为了验证这一假设并确定突变等位基因的频率，我们将研究150个果蝇品系的易位。在TE控制失灵的果蝇中，TE数量呈爆炸式增长。爆炸的可能性、速度和戏剧性有多大？控制转座速率的宿主基因是否有足够的变异来快速抑制TES的爆炸？我们的数据将有助于回答这些以及其他对保护生物学项目和旨在改善养殖种群的育种项目产生广泛影响的重要问题。此外，我们的研究将为本科生、研究生和博士后在分子群体遗传学和进化方面提供新的培训经验。

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.