High-resolution, genome-scale mapping of natural variation between reproductively isolated individuals

总结 遗传学的主要目标之一是了解自然变化的个体如何以及为什么在以下方面不同： 表型绘制这种性状变异的分子基础可以很简单，但只有在个体中， 可以杂交。我们已经发现，一种很少被研究的蠕虫物种，隐杆线虫， 寿命比相关线虫长50%，我们已经观察到强大的，保守的耐热性， 酿酒酵母是其分支中唯一可以作为机会致病菌的物种。在 目前的建议，我们解剖这些物种的分歧使用一个大规模的平行版本的互惠 半合子试验我们创造了一个基因组互补的半合子突变体，通过产生可行的，不育的F1 物种之间的杂交，并使它们进行转座子诱变。我们收集半合子， 它们的寿命和适合度在基于测序的测定中，并测试克隆之间的频率差异， 携带双亲的等位基因的池。结果是一个基因座目录， 物种间的差异会影响感兴趣的性状。在我们使用酵母（目标1）和蠕虫（目标2）的原理证明中， 我们将发现野生物种中出现的等位基因，以提高健康寿命和抗压力能力。这些 结果将与通常在种内研究中定位的弱化适合度的等位基因形成对比。 我们的酵母基因座的直系同源物将作为流行真菌中毒力基因的候选者， 病原体和我们的蠕虫寿命因子的直系同源物将非常适合分析抗衰老作用， 哺乳动物这项工作将是有史以来第一次全面调查的遗传结构和分子 生殖隔离个体之间性状变异的遗传学。我们所开创的方法将使 在任何真核系统中的遗传解剖，其中F1杂种个体或其组织的库被 available.

SUMMARY One of the primary goals of genetics is to understand how and why naturally varying individuals differ in phenotype. Mapping the molecular basis of this trait variation can be straightforward, but only in individuals that can be interbred. We have found that a little-studied worm species, Caenorhabditis latens, has a median lifespan 50% longer than related nematodes, and we have observed robust, conserved thermotolerance in Saccharomyces cerevisiae, the only species of its clade that can act as an opportunistic pathogen. In the current proposal, we dissect these species divergences using a massively parallel version of the reciprocal hemizygote test. We create a genomic complement of hemizygote mutants, by generating viable, sterile F1 hybrids between species and subjecting them to transposon mutagenesis. We pool the hemizygotes, measure their longevity and fitness in sequencing-based assays, and test for differences in frequency between clones of the pool bearing the two parents' alleles of a given gene. The result is a catalog of loci at which variants between species influence the trait of interest. In our proof of principle using yeast (Aim 1) and worm (Aim 2), we will uncover alleles that have arisen in wild species to boost healthspan and stress resistance. These results will stand in contrast to the alleles weakening fitness that are often mapped in intra-specific studies. Orthologs of our yeast loci will be of immediate interest as candidates for virulence genes in prevalent fungal pathogens, and orthologs of our worm lifespan factors will be well-suited to analysis for anti-aging effects in mammals. This effort will be the first-ever comprehensive survey of the genetic architecture and molecular genetics of trait variation between reproductively isolated individuals. And the methods we pioneer will enable genetic dissection in any eukaryotic system in which banks of F1 hybrid individuals or their tissues are available.