SGER: Alu Repeats in Higher Primates

在人类和其他灵长类物种的基因组（染色体）中估计有50万个Alu重复DNA元素。大多数重复出现在进化的过去（大约1000万到2000万年前），其他重复仍然出现在新的基因组位点；因此，他们的总数不断增加。了解这些Alu元素的扩散模式是很重要的。本提案的目的是确定Alu重复序列在我们的基因组中是固定的还是短暂的（多态），以及在多大程度上是固定的；不管它们是可逆的还是不可逆的。多态性模糊了有意义和无意义变化之间的区别，使遗传分析变得非常复杂。一个特征的固定或多态状态是不可能预测的，它必须通过分析大量的个体来建立。如果可以确定Alu重复序列传播的模式是不可逆的，那么Alu序列就可以被视为我们基因组进化动力学的坚实里程碑，并将成为系统发育分析的宝贵工具。

There are an estimated 500,000 Alu repetitive DNA elements in the genome (chromosomes) of humans and other primate species. Most of the repeats have arisen in the evolutionary past (some 10 to 20 million years ago), others are still arising at new genomic sites; thus their total number keeps increasing. It is important to understand the mode of spreading of these Alu elements. The objective of this proposal is to establish if, and to what extent, Alu repeats are fixed or transient (polymorphic) in our genome; whether they arise in reversible or irreversible mechanisms. Polymorphism greatly complicates genetic analyses by blurring the distinction between meaningful and meaningless changes. The fixed or polymorphic state of a character is impossible to predict, it has to be established by analyzing large numbers of individuals. If the mode by which Alu repeats spread can be established as being irreversible, Alu's can be viewed as solid landmarks in the evolutionary dynamics of our genome and will become invaluable tools for phylogenetic analyses.