Rocha Rita Gomes, Ferreira Eduardo, Fonseca Carlos, Justino Juliana, Leite Yuri Luiz Reis, Costa Leonora Pires
CESAM and Departamento de Biologia, Universidade de Aveiro Campus de Santiago, Aveiro, 3810-193, Portugal ; Laboratório de Mastozoologia e Biogeografia, Departamento de Ciências Biológicas, Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito Santo Av Goiabeiras, 29075-910, Vitória, ES, Brazil.
CESAM and Departamento de Biologia, Universidade de Aveiro Campus de Santiago, Aveiro, 3810-193, Portugal.
Ecol Evol. 2014 Dec;4(24):4598-608. doi: 10.1002/ece3.1336. Epub 2014 Nov 30.
Although codistributed species are affected by the same abiotic factors, such as rivers and seasonal flooding regimes, ecological traits, such as locomotion habits and habitat preferences, may also influence differences in levels of genetic diversity and differentiation. We examined population genetic structure and diversity of Hylaeamys megacephalus and Oecomys aff. roberti, two cricetid rodent species from the mid-Araguaia River in central Brazil, using mitochondrial DNA sequence data. Specifically, we aim to test whether the Araguaia River acts as a barrier to the gene flow of these two species and to assess how ecological traits, such as locomotion habits and habitat preferences, may influence differences in levels of genetic diversity and differentiation. As both species occur in flooded forests, neither showed genetic differences related to river banks. Oecomys aff. roberti showed stronger population structure that appears to be associated with isolation by distance. This arboreal species maintained stable populations in the Araguaia River, while the terrestrial H. megacephalus was more affected by seasonal floods, resulting in a genetic signature of population expansion. Our initial predictions were largely supported by our results given that locomotion habits and habitat preferences of each species appears to have played a role on the genetic structure of these two sympatric rodent species.
尽管共同分布的物种受到相同的非生物因素影响，如河流和季节性洪水状况，但生态特征，如运动习性和栖息地偏好，也可能影响遗传多样性和分化水平的差异。我们利用线粒体DNA序列数据，研究了来自巴西中部阿拉瓜亚河中游的两种仓鼠科啮齿动物——巨头溪鼠（Hylaeamys megacephalus）和近罗氏稻鼠（Oecomys aff. roberti）的种群遗传结构和多样性。具体而言，我们旨在测试阿拉瓜亚河是否对这两个物种的基因流动起到屏障作用，并评估运动习性和栖息地偏好等生态特征如何影响遗传多样性和分化水平的差异。由于这两个物种都出现在水淹森林中，两者均未表现出与河岸相关的遗传差异。近罗氏稻鼠表现出更强的种群结构，这似乎与距离隔离有关。这种树栖物种在阿拉瓜亚河维持着稳定的种群，而陆栖的巨头溪鼠受季节性洪水的影响更大，导致了种群扩张的遗传特征。鉴于每个物种的运动习性和栖息地偏好似乎对这两种同域分布的啮齿动物的遗传结构都起到了作用，我们的初步预测在很大程度上得到了结果的支持。
