Centro de Estudios Avanzados en Ecología y Biodiversidad, CASEB, and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
PLoS One. 2012;7(3):e32206. doi: 10.1371/journal.pone.0032206. Epub 2012 Mar 1.
The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000-13,000 years ago). Neutrality tests and the "g" parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats.
长尾侏仓鼠（Oligoryzomys longicaudatus）（Sigmodontinae）是智利和巴塔哥尼亚阿根廷的汉坦病毒的主要宿主，广泛分布于智利的地中海、温带和巴塔哥尼亚森林，以及阿根廷南部的相邻地区。我们使用分子数据评估了末次冰期事件对该物种的系统地理结构的影响。我们研究了历史上新世事件是否影响了该物种在其分布范围内的遗传变异和空间分布。我们在物种分布范围内的 47 个地点采集了 223 个个体，并对 mtDNA 控制区的高变区 I 进行了测序。对齐后的序列通过单倍型网络、贝叶斯种群结构和种群动态分析进行了分析。种群结构分析和单倍型网络推断，在 O. longicaudatus 的分布范围内存在三个遗传聚类，这与智利的三个主要生态地理区域基本一致：地中海、温带森林和巴塔哥尼亚森林。贝叶斯天空线图显示，在 LGM（26000-13000 年前）前后，所有三个聚类的种群大小均保持稳定，随后增加。中性检验和“g”参数也表明，O. longicaudatus 的种群经历了整个物种范围内的种群扩张。过去的气候变化影响了 O. longicaudatus 的种群结构和谱系变异。在更新世时期，这种物种在南部温带森林（以及巴塔哥尼亚的相邻地区）的避难所地区存活下来。从这些避难所中，O. longicaudatus 在冰川退缩的情况下，经历了向巴塔哥尼亚森林和智利中部地中海的种群扩张。
