Warringer Jonas, Liti Gianni, Blomberg Anders
Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden;
Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences (UMB), 1432 Ås, Norway.
Cold Spring Harb Protoc. 2017 Aug 1;2017(8):pdb.prot089078. doi: 10.1101/pdb.prot089078.
Pinpointing causal alleles within a quantitative trait loci region is a key challenge when dissecting the genetic basis of natural variation. In yeast, homing in on culprit genes is often achieved using engineered reciprocal hemizygotes as outlined here. Based on prior information on gene-trait associations, candidate genes are identified. In haploid versions of both founder strains, a candidate gene is then deleted. Gene knockouts are independently mated to a wild-type version of the other strain, such that two diploid hybrid strains are obtained. These strains are identical with regard to the nuclear genome, except for that they are hemizygotic at the locus of interest and contain different alleles of the candidate gene. If correctly measured, a trait difference between these reciprocal hemizygotes can confidently be ascribed to allelic variation at the target locus.
在剖析自然变异的遗传基础时，在数量性状基因座区域内确定因果等位基因是一项关键挑战。在酵母中，如本文所述，通常使用工程化的相互半合子来锁定致病基因。根据基因与性状关联的先验信息，确定候选基因。然后在两个创始菌株的单倍体版本中删除一个候选基因。基因敲除菌株分别与另一个菌株的野生型版本杂交，从而获得两个二倍体杂交菌株。这些菌株在核基因组方面是相同的，只是在感兴趣的基因座处是半合子，并且包含候选基因的不同等位基因。如果测量正确，这些相互半合子之间的性状差异可以可靠地归因于目标基因座处的等位基因变异。
