Population Genetics of Transposable Elements

9527717查尔斯沃斯转座元件(TES)是在包括人类在内的大多数生物的基因组中以多个副本存在的脱氧核糖核酸序列。它们可以制造自己的新副本，可以插入到基因组的新位置。有时，这些插入会导致附近基因的突变，而人类遗传病中涉及的一些突变就是这样产生的。似乎很明显，TE至少在一定程度上就像寄生在宿主基因组上的寄生虫，利用它们作为自己传播的媒介。负责控制寄主基因组中TES丰度的力量是一个继续研究的问题。了解这些力量对于我们了解塑造基因组组织的因素和突变的起源是重要的。果蝇是研究这些问题的有用模式生物。在果蝇和其他生物(如人类)中，TES的特性是相似的；在果蝇中，较短的世代时间和易于研究使遗传问题比较大的有机体更有效地解决。这项拟议的研究继续调查果蝇TES的种群水平特性。一个主要目标是获得更准确的果蝇TES在基因组中移动的速度的估计；这些信息对于解释先前关于TES在个体之间的分布的研究是至关重要的。第二个目标是检查在所有被研究个体的基因组中特定位置插入的TE。这些情况是例外的，因为TE插入的不利影响通常意味着只在给定位置以低频率发现TE插入。

9527717 CHARLESWORTH Transposable elements (TEs) are DNA sequences that are present in multiple copies in the genomes of most organisms, including humans. They can make new copies of themselves, which can insert into new places in the genome. Sometimes these insertions cause mutations of nearby genes, and a number of mutations involved in human genetic diseases have originated this way. It seems clear that TEs behave, at least in part, as parasites on the genomes of their hosts, using them as a vehicle for their own transmission. The forces responsible for controlling the abundances of TEs in the genomes of their hosts are a matter for continuing research. Understanding these forces is important for our knowledge of the factors that shape the organization of the genome, and for the origin of mutations. The fruitfly Drosophila is a useful model organism for research into these questions. The properties of TEs are similar in Drosophila and other organisms such as humans; in Drosophila the short generation time and ease of study allow genetic questions to be addressed much more efficiently than in larger organisms. The proposed research continues an investigation of the population-level properties of Drosophila TEs. A major objective is to obtain more precise estimates of the rates at which Drosophila TEs move around the genome; this information is vital for interpreting previous studies of the distribution of TEs between individuals. A second objective is to examine TEs that are inserted at a particular site in the genome in all studied individuals. These cases are exceptional, as the adverse effects of TE insertions usually mean that TE insertions are found only at low frequencies at a given location.