Valdez Lourdes, D'Elía Guilermo
Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
PeerJ. 2018 Dec 18;6:e6130. doi: 10.7717/peerj.6130. eCollection 2018.
Quaternary climatic oscillations have impacted Patagonian sigmodontine fauna, leaving traceable genetic footprints. In southern Chile, changes in the landscape included transitions to different vegetation formations as well as the extension of ice sheets. In this study, we focus on the Valdivian forest endemic and recently described sigmodontine species . We aim to assess the genetic structure of this species, testing for the existence of intraspecific lineages, and inferring the recent demographic history of the species. Analyses were based on the first 801 bp of the mitochondrial gene Cytocrhome-b from 49 individuals of collected at 10 localities that covers most part of its geographic distribution. Genealogical analyses recovered two main intraspecific lineages that are geographically segregated and present an intermediate site of secondary contact. Historical demography shows signal of recent population decrease. Based on these results, we proposed that current genetic diversity of differentiated in at least two distinct refugial areas in southern Chile. This scenario, in addition to be unique among those uncovered for the so far studied Valdivian forest rodents, is noteworthy because of the reduced geographic scale inhabited by the species.
第四纪气候振荡对巴塔哥尼亚稻鼠科动物产生了影响，留下了可追溯的基因印记。在智利南部，景观变化包括向不同植被形态的转变以及冰盖的扩张。在本研究中，我们聚焦于瓦尔迪维亚森林特有的、最近才被描述的稻鼠科物种。我们旨在评估该物种的遗传结构，检测种内谱系的存在，并推断该物种近期的种群历史。分析基于从10个地点收集的49个个体的线粒体细胞色素b基因的前801个碱基对，这些地点覆盖了其地理分布的大部分区域。系统发育分析发现了两个主要的种内谱系，它们在地理上是隔离的，并且存在一个二次接触的中间位点。历史种群统计学显示出近期种群减少的信号。基于这些结果，我们提出，目前该物种的遗传多样性是在智利南部至少两个不同的避难区域分化形成的。这种情况，除了在迄今为止所研究的瓦尔迪维亚森林啮齿动物中独一无二之外，还因其所占据的地理范围缩小而值得关注。
