The evolution of genetic systems

我们的实验室研究交配系统的修饰符的进化，更普遍的是，偏向自己传播的基因。我们建议进行研究的进化和丧失的自交不亲和性（SI）在植物Leavenacrotia。 这项研究将调查交配系统的进化，从人口的水平上下降到基因序列，并将集中在S-位点的变化。在过去的10年里，研究人员在拟南芥属中克隆和测序了该基因座，取得了相当大的进展。我们将利用这一知识，扩大研究的进化和SI的损失，以一个植物群，其生态已得到很好的表征。 我们已经在该项目的一些组成部分上取得了重大进展，首先是使用靶向S基因座的一些保守区域的PCR引物作为克隆和测序基因的手段。 我们的目标包括：（1）确认扩增产物与S基因座相对应;（2）发展和检验等位基因谱系的新的和现有的理论以及导致自交亲和的S基因座突变的动态;（3）检验SI群体中群体大小变异对配偶可用性和繁殖力的影响;（4）在Leavenalia属植物的自交亲和群体中进行S-位点的选择性扫描试验，（5）利用古老的S-位点多态性数据重建Leavenalia属植物交配系统的进化历史;（6）对S-位点区域有害突变的筛选的屏蔽试验。 总的来说，这项研究将扩展我们对植物自花受精进化的理解。 还建议完成一个项目，以调查转座因子（TE）序列进化的早期阶段伴随着“入侵”的一个新的基因组的异源TE（TE从另一个物种）到实验群体的酵母。 这两个项目在概念上是相关的，因为它们都关注能够偏向自身传播的基因的进化，这是我们实验室探索了20多年的一个主题。

Our lab studies the evolution of modifiers of the mating system, and more generally, genes that bias their own transmission. We propose to conduct studies of the evolution and loss of self-incompatibility (SI) in the plant genus Leavenworthia. This research will investigate mating system evolution from the level of the population on down to the gene sequence, and will focus on variation at the S-locus. Considerable progress has been made in the past 10 years by researchers who have cloned and sequenced this locus in the related genus Arabidopsis. We will capitalize upon this knowledge to extend the study of evolution and loss of SI to a plant group whose ecology has been well characterized. We have already made significant progress on a number of components of this project, starting with the use of PCR primers that target a number of conserved regions of the S-locus as the means to clone and sequence the gene. Our goals include: (1) confirmation that amplified products correspond to the S-locus; (2) development and testing of new and existing theory for allele genealogy and the dynamics of mutations at the S-locus that lead to self-compatibility; (3) examination of the effect of population size variation on mate availability and fecundity in SI populations; (4) tests for a selective sweep at the S-locus in self-compatible populations of Leavenworthia species; (5) using ancient S-locus polymorphism data to assist in reconstruction of the evolutionary history of the mating system in Leavenworthia species; (6) tests for the sheltering from selection of deleterious mutations in the S-locus region. Collectively, this research will extend our understanding of the evolution of self-fertilization in plants. Also proposed is the completion of a project to investigate the early stages of transposable element (TE) sequence evolution accompanying the "invasion" of a new genome by a heterologous TE (TE from another species) into experimental populations of yeast. The two projects are conceptually related in that both are concerned with the evolution of genes that have the ability to bias their own transmission, a topic that our lab has explored for more than 20 years.