Alhazmi Doaa, Fudyk Seth Kaleb, Civetta Alberto
Department of Biology, University of Winnipeg, MB, Canada, R3B 2E9.
Department of Biology, University of Winnipeg, MB, Canada, R3B 2E9
G3 (Bethesda). 2019 Apr 9;9(4):1065-1074. doi: 10.1534/g3.119.300580.
Hybrid male sterility (HMS) is a form of postmating postzygotic isolation among closely related species that can act as an effective barrier to gene flow. The Dobzhansky-Muller model provides a framework to explain how gene interactions can cause HMS between species. Genomics highlights the preponderance of non-coding DNA targets that could be involved in gene interactions resulting in gene expression changes and the establishment of isolating barriers. However, we have limited knowledge of changes in gene expression associated with HMS, gene interacting partners linked to HMS, and whether substitutions in DNA regulatory regions () causes misexpression (, expression of genes beyond levels found in parental species) of HMS genes in sterile hybrids. A previous transcriptome survey in a pair of species found male reproductive tract (MRT) proteases as the largest class of genes misregulated in sterile hybrids. Here we assay gene expression in backcross (BC) and introgression (IG) progeny, along with site of expression within the MRT, to identify misexpression of proteases that might directly contribute to HMS. We find limited evidence of an accumulation of -regulatory changes upstream of such candidate HMS genes. The expression of four genes was differentially modulated by alleles of the previously characterized HMS gene .
杂种雄性不育（HMS）是密切相关物种之间一种交配后合子后隔离的形式，可作为基因流动的有效障碍。多布赞斯基-穆勒模型提供了一个框架，用于解释基因相互作用如何导致物种间的HMS。基因组学突出了非编码DNA靶点的优势，这些靶点可能参与基因相互作用，导致基因表达变化和隔离屏障的建立。然而，我们对与HMS相关的基因表达变化、与HMS相关的基因相互作用伙伴，以及DNA调控区域的替代是否会导致不育杂种中HMS基因的错误表达（即基因表达水平超过亲本物种中发现的水平）了解有限。之前对一对物种的转录组调查发现，雄性生殖道（MRT）蛋白酶是不育杂种中调控错误的最大一类基因。在这里，我们检测了回交（BC）和渐渗（IG）后代中的基因表达，以及MRT内的表达位点，以确定可能直接导致HMS的蛋白酶的错误表达。我们发现，在这些候选HMS基因上游积累调控变化的证据有限。四个基因的表达受到先前鉴定的HMS基因等位基因的差异调节。
