Doctoral Dissertation Improvement: Genetic Transposition of Baboon Endogenous Virus (BaEV) in Hybrid Old World Monkeys (Primates: Papionini)

在《物种起源》出版140多年后，导致新的、一贯不同的种群出现和遗传稳定的过程仍然是人们最不了解的进化过程之一。 虽然各种机制可能与遗传隔离有关，但最近的注意力集中在基因组水平的特征上，这些特征既快速进化，又可以大大降低其携带者杂交和产生可行的杂交后代的能力。 最近的各种证据暗示转座因子（TE）在促进这种生殖隔离。 TE是小的（100- 10 kb碱基对）遗传元件，保留了它们在基因组内移动的能力。 对果蝇和小袋鼠等多种生物进行的调查表明，转座因子的活性与菌株间杂种的不育性之间存在正相关。 为了确定TE介导的种群间杂交障碍可能如何演变，本研究的目的是通过检测狒狒内源性病毒（BaEV）的证据来研究TE扩增与杂交性之间的关系。在一个分级系列的旧大陆猴杂交种中的papionin组的转座。 BaEV是一种内源性逆转录病毒，曾经在个体之间水平传播，但现在形成了许多旧大陆猴垂直遗传基因组的组成部分。 逆转录病毒是最复杂的TE形式之一，具有可以通过逆转录的内在驱动过程产生拷贝的大基因组。 因此，本项目将调查TE活动和生殖隔离之间的关系，通过测试在不同程度的混合血统的papionin杂交的BaEV扩增。 拟议的研究的具体目标是：确定BaEV扩增与杂交不育相关的程度;确定随着亲本类群之间进化距离的增加，BaEV扩增在杂交木瓜蛋白酶中增加的程度;检测可能归因于特定杂交事件的具有已知亲本的个体中的新BaEV整合;并确定野生灵长类种群中BaEV序列变异的程度。 这些目标将通过对反映不同程度的杂交血统的一系列分级杂交木瓜蛋白酶进行取样来实现。 这些数据将作为第一步，在确定的贡献TE的生殖隔离在papionins。

More than 14 decades after the publication of "On the Origin of Species," the processes leading to the appearance and genetic stabilization of new, consistently distinct populations remains one of the least understood of evolutionary processes. While a variety of mechanisms may be associated with genetic isolation, attention recently has focussed upon genome-level features that are both rapidly-evolving and can drastically reduce the ability of their carriers to interbreed and produce viable hybrid offspring. A variety of recent evidence implicates transposable elements (TEs) in facilitating such reproductive isolation. TEs are small (100-10kb base pairs) genetic elements that have retained their ability to move about within genomes. Investigations conducted on organisms as diverse as fruit flies and wallabies suggest that there is a positive correlation between transposable element activity and sterility in inter-strain hybrids. In order to determine how TE-mediated barriers to inter-population hybridization might evolve, it is necessary to examine the behavior of such elements in fertile hybrids and their progeny in naturally occurring hybrid zones.The goal of this project is to investigate the relationship between TE amplification and hybridity by testing for evidence of baboon endogenous virus (BaEV) transposition in a graded series of Old World Monkey hybrids in the papionin group. BaEV is an endogenous retrovirus that was once transmitted horizontally from individual to individual but now forms an integrated part of the vertically inherited genome of many Old World Monkeys. Retroviruses are one of the most complex TE forms, with large genomes that can generate copies through the intrinsically driven process of reverse transcription. This project will thus investigate the relationship between TE activity and reproductive isolation by testing BaEV amplification in papionin hybrids with varying degrees of hybrid ancestry. The specific aims of the proposed research are: to determine the degree to which BaEV amplification is correlated with hybrid sterility; to determine the degree to which BaEV amplification increases in hybrid papionins with increased evolutionary distance between parental taxa; to detect novel BaEV integrations in individuals with known parentage that may be attributable to specific hybridization events; and to determine the extent of BaEV sequence variation in a wild primate population. These objectives will be accomplished by sampling a graded series of hybrid papionins reflecting different degrees of hybrid ancestry. These data will serve as a first step in determining the contribution of TEs to reproductive isolation in papionins.