Dissertation Research: Selective Neutrality of MitochondrialDNA Genotypes

线粒体DNA(MtDNA)是一组核外、母系遗传的基因，被认为是选择性中性的；也就是说，它们在种群中的分布只受偶然事件的影响，而不受这些基因赋予的进化适应性的差异。该项目的目标是检测线粒体基因对生物体形态或核基因构成的影响。这是了解线粒体和核基因相互作用如何影响发育的第一步，从而了解线粒体DNA基因型如何通过自然选择进化。野生鲑鱼的种群，已知是进化上不同的种群之间的杂交，将被研究。由这种不同的分类群形成的随机交配的杂交蜂群在自然界中很少见。他们将允许对mtDNA基因与核基因、性别和形态(椎骨数量、波动不对称等)之间的相关性进行统计测试。证明线粒体DNA受到自然选择的影响，将对广泛使用线粒体DNA作为遗传变异和种群结构研究的标记具有重要意义。此外，鲑鱼野生种群是一种重要的自然资源，其完整性受到与引进物种杂交的严重威胁。这项研究将加深我们对鲑科鱼类种间杂交动态的了解。

Mitochondrial DNA (mtDNA) is an extra-nuclear, maternally inherited set of genes assumed to be selectively neutral; that is, their distribution within populations is subject only to chance events, and not to differences in evolutionary fitness conferred by these genes. The goal of this project is to detect effects, if any, of mitochondrial genes on an organism's morphology or nuclear genetic makeup. This is a first step towards understanding how mitochondrial and nuclear gene interactions may affect development, and , thus, how mtDNA genotypes may be subject to evolution by natural selection. Populations of wild trout, known to be hybrids between evolutionarily divergent groups, will be studied. Randomly mating hybrid swarms formed from such distinct taxa are rare in nature. They will permit statistical tests for association between mtDNA genotype and nuclear genotype, sex, and morphology (number of vertebrae, fluctuating asymmetry, etc.). Demonstration that mtDNA is subject to natural selection would have important implications for the widespread use of mtDNA as a marker for studies of genetic variation and population structure. Also, wild populations of trout are an important natural resource, the integrity of which is seriously threatened by hybridization with introduced species. This study will add to our understanding of the dynamics of interspecies hybridization in salmonid fishes.