Fat frogs, mobile genes: unexpected phylogeographic patterns for the ornate chorus frog (Pseudacris ornata)
Fat frogs, mobile genes: unexpected phylogeographic patterns for the ornate chorus frog (Pseudacris ornata)
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DOI：
10.1111/j.1365-294x.2010.04661.x
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发表时间：
2010-06-01
影响因子：
4.9
通讯作者：
Hoffman, Eric A.
中科院分区：
文献类型：
--
作者：
Degner, Jacob F.;Silva, Diana M.;Hoffman, Eric A.
美国东南部沿海平原是一个具有非凡的地理一致性的地区，这通常归因于更新世时期冰川-间冰期循环期间发生的海平面变化。到目前为止，许多物种的研究表明，该地区特有的地理中断对应于阿巴拉契科拉河。在这里，我们使用这种模式的地理一致性，以发展和测试明确的假设的遗传结构在华丽的合唱青蛙（Pseudacris ornata）。利用1299 bp的线粒体DNA序列和7个核微卫星标记，在13个自然种群的P. ornata，我们发现了三个分支对应的地理上不同的地区;一个跨越阿巴拉契科拉河（南部分支），一个包括格鲁吉亚和南卡罗来纳州（中央分支）和第三个包括更北的个人（北方分支）。然而，它并没有出现典型的地理屏障划分这些分支。相反，整个物种范围内的距离隔离解释了我们观察到的遗传变异模式。我们认为，P. ornata在历史上广泛分布于美国东南部，遗传漂变和迁移之间的平衡是种群间遗传分化的根源。此外，我们调查了遗传结构的精细尺度模式，发现在所研究的区域之间存在显着遗传结构的空间尺度不同。此外，我们讨论了我们的研究结果，根据东南沿海平原生物和两栖动物的保护和管理的其他生态地理研究。
The southeastern coastal plain of the United States is a region marked by extraordinary phylogeographic congruence that is frequently attributed to the changing sea levels that occurred during the glacial-interglacial cycles of the Pleistocene epoch. A phylogeographic break corresponding to the Apalachicola River has been suggested for many species studied to date that are endemic to this region. Here, we used this pattern of phylogeographic congruence to develop and test explicit hypotheses about the genetic structure in the ornate chorus frog (Pseudacris ornata). Using 1299 bp of mtDNA sequence and seven nuclear microsatellite markers in 13 natural populations of P. ornata, we found three clades corresponding to geographically distinct regions; one spans the Apalachicola River (Southern Clade), one encompasses Georgia and South Carolina (Central Clade) and a third comprises more northerly individuals (Northern Clade). However, it does not appear that typical phylogeographic barriers demarcate these clades. Instead, isolation by distance across the range of the entire species explained the pattern of genetic variation that we observed. We propose that P. ornata was historically widespread in the southeastern United States, and that a balance between genetic drift and migration was the root of the genetic divergence among populations. Additionally, we investigated fine-scale patterns of genetic structure and found the spatial scale at which there was significant genetic structure varied among the regions studied. Furthermore, we discuss our results in light of other phylogeographic studies of southeastern coastal plain organisms and in relation to amphibian conservation and management.