Department of Biology, UNESP - São Paulo State University, São José do Rio Preto, São Paulo State (SP), Brazil.
Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR 5558, Université Claude Bernard Lyon 1, University of Lyon, 69622, Villeurbanne, France.
Sci Rep. 2021 May 10;11(1):9844. doi: 10.1038/s41598-021-89366-2.
Interspecific hybridization is a stressful condition that can lead to sterility and/or inviability through improper gene regulation in Drosophila species with a high divergence time. However, the extent of these abnormalities in hybrids of recently diverging species is not well known. Some studies have shown that in Drosophila, the mechanisms of postzygotic isolation may evolve more rapidly in males than in females and that the degree of viability and sterility is associated with the genetic distance between species. Here, we used transcriptomic comparisons between two Drosophila mojavensis subspecies and D. arizonae (repleta group, Drosophila) and identified greater differential gene expression in testes than in ovaries. We tested the hypothesis that the severity of the interspecies hybrid phenotype is associated with the degree of gene misregulation. We showed limited gene misregulation in fertile females and an increase in the amount of misregulation in males with more severe sterile phenotypes (motile vs. amotile sperm). In addition, for these hybrids, we identified candidate genes that were mostly associated with spermatogenesis dysfunction.
种间杂交是一种应激条件，可能会导致不育和/或不可育，这是由于具有高分化时间的果蝇物种中基因调控不当。然而，最近分化的物种之间的杂种中这些异常的程度还不是很清楚。一些研究表明，在果蝇中，合子后隔离的机制在雄性中可能比在雌性中进化得更快，并且可育性和不育性的程度与物种之间的遗传距离有关。在这里，我们使用了两个 Drosophila mojavensis 亚种和 D. arizonae（repleta 组，果蝇）之间的转录组比较，并发现睾丸中的差异基因表达高于卵巢。我们检验了这样一个假设，即种间杂交表型的严重程度与基因失调的程度有关。我们发现，可育雌性的基因失调程度有限，而具有更严重不育表型（有活力与无活力精子）的雄性的基因失调程度增加。此外，对于这些杂种，我们鉴定了与精子发生功能障碍相关的候选基因。
