Molecular Population Genetics of Transposable Elements in Drosophila

转座因子或TE，作为所谓的“自私DNA”的例子，其功能是确保其自身的生存和繁殖，存在于所有生物体的染色体中（以多个拷贝），经常引起突变。TE自身基因组的一部分致力于独立于宿主基因指导其自身繁殖，从而使其能够迅速通过宿主生物体的染色体传播，即使TE具有轻微的有害影响。已知果蝇（Drosophila melanogaster）具有大量不同种类的转座因子。当其中一种被称为流浪汉的元素在染色体间移动时，它会导致杂种发育不全，从而导致不育、高突变率、染色体断裂和其他有害影响，因此它在数千年的进化中的持续性是相当令人困惑的。通过比较不同种群和其他密切相关的果蝇物种中流浪汉元件的DNA序列（D。例如，模拟人），将有可能了解流浪汉分子进化的速度，什么选择力改变了遗传功能，以及物种之间的TE传播模式。从长远来看，这种类型的研究预计将产生一个基本的理解，生物体如何处理“DNA寄生虫”随着时间的推移，以及如何通过突变的TE的行动，导致有用的，新的基因功能。

Transposable elements or TEs, which as examples of so- called "selfish DNA" function to ensure their own survival and reproduction, exist (in multiple copies) in the chromosomes of all organisms, often causing mutations. A portion of the TE's own genome is devoted to directing its own reproduction independently of the host's genes, thereby enabling it to spread through a host organism's chromosomes quickly, even if the TE has a slightly detrimental effect. Drosophila melanogaster, the fruit fly, is known to have a large number of different kinds of transposable elements. When one such element, called hobo, moves among chromosomes, it causes hybrid dysgenesis, which leads to sterility, high mutation rates, chromosome breaks, and other deleterious effects, so its persistence over millennia of evolution is quite puzzling. By comparing DNA sequences of hobo elements in different populations and in other closely related Drosophila species (D. simulans for example), it will be possible to learn about the rate at which hobo elements have evolved, what selective forces have acted to modify genetic function, and mode of TE transmission between species. In the long run, studies of this type are expected to yield a fundamental understanding of how organisms have dealt with "DNA parasites" over time, as well as how the action of TEs, via mutation, have led to useful, novel gene functions.