School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA.
Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA.
G3 (Bethesda). 2022 Feb 4;12(2). doi: 10.1093/g3journal/jkab402.
Despite playing a critical role in evolutionary processes and outcomes, relatively little is known about rates of recombination in the vast majority of species, including squamate reptiles-the second largest order of extant vertebrates, many species of which serve as important model organisms in evolutionary and ecological studies. This paucity of data has resulted in limited resolution on questions related to the causes and consequences of rate variation between species and populations, the determinants of within-genome rate variation, as well as the general tempo of recombination rate evolution on this branch of the tree of life. In order to address these questions, it is thus necessary to begin broadening our phylogenetic sampling. We here provide the first fine-scale recombination maps for two species of spiny lizards, Sceloporus jarrovii and Sceloporus megalepidurus, which diverged at least 12 Mya. As might be expected from similarities in karyotype, population-scaled recombination landscapes are largely conserved on the broad-scale. At the same time, considerable variation exists at the fine-scale, highlighting the importance of incorporating species-specific recombination maps in future population genomic studies.
尽管在进化过程和结果中发挥着关键作用,但对于绝大多数物种(包括蜥蜴目爬行动物——现存脊椎动物的第二大目,其中许多物种是进化和生态研究中的重要模式生物)的重组率,我们知之甚少。由于数据的匮乏,导致我们对物种和种群之间的重组率变化的原因和结果、基因组内重组率变化的决定因素以及这一生命之树分支上重组率进化的总体节奏等问题的解析受到限制。因此,为了解决这些问题,有必要开始扩大我们的系统发育采样。在这里,我们为两种有刺蜥蜴(Sceloporus jarrovii 和 Sceloporus megalepidurus)提供了第一个精细尺度的重组图谱,它们至少在 1200 万年前就已经分化。从染色体组的相似性来看,种群尺度的重组景观在大尺度上基本保持一致。与此同时,在精细尺度上也存在着相当大的差异,这突出了在未来的种群基因组研究中纳入物种特异性重组图谱的重要性。