Stevison Laurie S, Bailey Nick P, Szpiech Zachary A, Novak Taylor E, Melnick Don J, Evans Ben J, Wall Jeffrey D
Department of Biological Sciences Auburn University Auburn Alabama USA.
Department of Biology Pennsylvania State University University Park Pennsylvania USA.
Ecol Evol. 2022 May 24;12(5):e8897. doi: 10.1002/ece3.8897. eCollection 2022 May.
Genital divergence is thought to contribute to reproductive barriers by establishing a "lock-and-key" mechanism for reproductive compatibility. One such example, , the bear macaque, has compensatory changes in both male and female genital morphology as compared to close relatives. . also has a complex evolutionary history, having extensive introgression between the and macaque species groups. Here, phylogenetic relationships were analyzed via whole-genome sequences from five species, including . , and two species each from the putative parental species groups. This analysis revealed ~3x more genomic regions supported placement in the species group as compared to the species group. Additionally, introgression analysis of the . genome revealed it is a mosaic of recent polymorphisms shared with both species groups. To examine the evolution of their unique genital morphology further, the prevalence of candidate genes involved in genital morphology was compared against genome-wide outliers in various population genetic metrics of diversity, divergence, introgression, and selection, while accounting for background variation in recombination rate. This analysis identified 67 outlier genes, including several genes that influence baculum morphology in mice, which were of interest since the bear macaque has the longest primate baculum. The mean of four of the seven population genetic metrics was statistically different in the candidate genes as compared to the rest of the genome, suggesting that genes involved in genital morphology have increased divergence and decreased diversity beyond expectations. These results highlight specific genes that may have played a role in shaping the unique genital morphology in the bear macaque.
生殖器差异被认为通过建立一种生殖兼容性的“锁钥”机制来促成生殖障碍。一个这样的例子，熊猴，与近亲相比，其雄性和雌性生殖器形态都有补偿性变化。熊猴也有复杂的进化历史，在熊猴和食蟹猴物种组之间有广泛的基因渗入。在这里，通过包括熊猴在内的五个物种以及分别来自假定亲本物种组的两个物种的全基因组序列分析了系统发育关系。该分析表明，与食蟹猴物种组相比，支持置于熊猴物种组的基因组区域多出约3倍。此外，对熊猴基因组的基因渗入分析表明，它是与两个物种组共有的近期多态性的镶嵌体。为了进一步研究其独特生殖器形态的进化，将涉及生殖器形态的候选基因的患病率与多样性、分化、基因渗入和选择的各种群体遗传指标中的全基因组异常值进行比较，同时考虑重组率的背景变化。该分析确定了67个异常基因，包括几个影响小鼠阴茎骨形态的基因，鉴于熊猴拥有灵长类动物中最长的阴茎骨，这些基因很有趣。与基因组的其余部分相比，七个群体遗传指标中的四个指标在候选基因中的平均值在统计学上存在差异，这表明涉及生殖器形态的基因的分化增加且多样性降低，超出预期。这些结果突出了可能在塑造熊猴独特生殖器形态中发挥作用的特定基因。
