Molecular Population Genetics of Inversion Polymorphism

[408869 . Kreitman]这项研究将检查与果蝇自然种群中自然发生的染色体重排相关的DNA序列特征。遗传物质的重排，例如由染色体易位和倒位引起的重排是常见的；然而，它们也与人类和其他物种的一些遗传疾病有因果关系。此外，多种重排与非重排染色体的异常分离也具有很强的危害性。尽管人们预期染色体物质的总体重排会产生强烈的负适应性后果，因此在自然界中应该是罕见的，但它们在许多物种的自然种群中以多态性的形式存在，并作为物种之间的固定差异，表明在某些情况下，许多反转必须是选择性中性或有利的。本研究的目的是研究几种倒位的历史，检验关于遗传变异维持的假设，以及研究染色体重排对断点附近基因表达和功能的影响。这项工作还将深入了解导致染色体断裂的分子机制。这些发现将直接适用于对人类变异和疾病的理解。

9408869 Kreitman This research will examine DNA sequence features associated with naturally occurring chromosomal rearrangements in natural populations of the fruitfly, Drosophila. Rearrangement of the genetic material, such as that caused by chromosomal translocations and inversions, are common; however, they are also causally associated with a number of genetic diseases in humans and other species. In addition, the aberrant segregation of many kinds of rearrangements with non-rearranged chromosomes in also strongly deleterious. Despite this expectation that gross rearrangement of chromosomal material will have strongly negative fitness consequences, and therefore should be rare in nature, their presence as polymorphisms in natural populations of many species and as fixed differences between species, suggests that many inversions must, in some cases, be selectively neutral or favorable. It is the goal of this research to examine the history of several inversions and to test hypotheses about the maintenance of genetic variation as well as to investigate the influence of chromosomal rearrangement on the expression and function of genes near the breakpoints. This work will also produce insights into the molecular mechanism(s) leading to chromosomal breakage. The findings will have direct applicability to the understanding of human variation and disease.