Genetic diversity and the origins of parthenogenesis in the teiid lizard Aspidoscelis laredoensis
Genetic diversity and the origins of parthenogenesis in the teiid lizard Aspidoscelis laredoensis
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DOI：
10.1111/mec.16213
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发表时间：
2021-10-19
影响因子：
4.9
通讯作者：
Thomson, Robert C.
中科院分区：
文献类型：
--
作者：
Barley, Anthony J.;Cordes, James E.;Thomson, Robert C.
单性脊椎动物通常通过有性物种之间的杂交事件形成，在杂交后代中发生生殖模式转变。这一进化历史被认为对单性谱系的生态学及其与自然群落中同系物的相互作用具有重要影响。然而，由于单性谱系中种群遗传多样性模式的不确定性，这些结果已被证明具有挑战性。特别感兴趣的是解决历史杂交事件与形成后突变对自然遗传多样性模式的贡献。本研究利用限制性位点相关DNA基因分型方法，对来自德克萨斯州南部和墨西哥北部里约热内卢格兰德河附近的一种二倍体单性蜥蜴——laredoensis的遗传多样性和人口统计学历史进行了评估。在里约热内卢格兰德谷地区也有衍生出一个或多个谱系的性祖先物种，尽管在各个地点的分布模式差异很大。群体遗传和系统发育分析的结果解决了该物种遗传变异的主要轴，并强调了这些预测是如何基于杂交的历史模式进行匹配的。我们还发现使用不同统计方法的人口统计学建模结果与基因组数据之间存在不一致。我们在单性物种中产生和维持谱系多样性的生态和进化机制的背景下讨论这些见解。作为最具活力、最有趣、地理上研究最充分的鞭尾蜥蜴群体之一，这些物种对未来研究单性脊椎动物多样化的限制有着巨大的希望。
Unisexual vertebrates typically form through hybridization events between sexual species in which reproductive mode transitions occur in the hybrid offspring. This evolutionary history is thought to have important consequences for the ecology of unisexual lineages and their interactions with congeners in natural communities. However, these consequences have proven challenging to study owing to uncertainty about patterns of population genetic diversity in unisexual lineages. Of particular interest is resolving the contribution of historical hybridization events versus post formational mutation to patterns of genetic diversity in nature. Here we use restriction site associated DNA genotyping to evaluate genetic diversity and demographic history in Aspidoscelis laredoensis, a diploid unisexual lizard species from the vicinity of the Rio Grande River in southern Texas and northern Mexico. The sexual progenitor species from which one or more lineages are derived also occur in the Rio Grande Valley region, although patterns of distribution across individual sites are quite variable. Results from population genetic and phylogenetic analyses resolved the major axes of genetic variation in this species and highlight how these match predictions based on historical patterns of hybridization. We also found discordance between results of demographic modelling using different statistical approaches with the genomic data. We discuss these insights within the context of the ecological and evolutionary mechanisms that generate and maintain lineage diversity in unisexual species. As one of the most dynamic, intriguing, and geographically well investigated groups of whiptail lizards, these species hold substantial promise for future studies on the constraints of diversification in unisexual vertebrates.