【每日翻译20190227】河流屏障对马达加斯加芦苇蛙系统地理格局的影响

编者信息

熊荣川

明湖实验室

xiongrongchuan@126.com

http://blog.sciencenet.cn/u/Bearjazz

原文：

The influence of riverine barriers on phylogeographic patterns of Malagasy reed frogs ( Heterixalus )

We analyzed the influence of large rivers

on the phylogeography of endemic widespread amphibians along Madagascar’s east

coast, using as models various species and species complexes of Malagasy reed frogs

(Heterixalus spp.) that are specialized to either highland or lowland habitats.

We assembled a dense sampling across the full species ranges and used

mitochondrial (cob) as well as nuclear (Rag-1) DNA sequences to assess their

phylogeographies. A multigene mtDNA phylogeny of each species was constructed

to establish the relationships among the main phylogroups, in order to

understand the geographical regions of clade origins and possible directions of

historical range expansions. Distinct intraspecific lineages as diagnosed by

mitochondrial haplotype clades were found in highlands and lowlands. Most

geographical boundaries among these phylogroups did not coincide with rivers,

indicating that the influence of rivers on the primary divergence of

phylogroups is probably minor in these frogs. Nevertheless, we found evidence

for the influence of one riverine barrier in the lowland species complex, where

the most important genetic discontinuity (the border between Heterixalus

madagascariensis and H. alboguttatus) coincides with the geographical position

of the Mangoro River on Madagascar’s central east coast. Analyses of the

highland species H. betsileo revealed the existence of six deep haplotype

lineages, separated in two major subpopulations which differ largely in

altitudinal distribution and do not overlap with the geographical settings of

rivers in the highlands. Furthermore, our analyses indicated that most of the

major intraspecific lineages of reed frogs show signs of a rather recent

population expansion.

译文：

我们分析了大型河流对马达加斯加东海岸特有的广布两栖动物系统地理的影响，并将马达加斯加芦苇蛙（heterixalus spp.）的各种物种和物种复合体作为模型，它们要么是专属于高地生境，要么是专属于低地生境的。我们在整个物种范围内进行了密集采样，并使用线粒体基因（COB）和核基因（RAG-1）DNA序列来评估它们的系统地理。构建了各物种的多基因mtDNA系统发育模型，建立了各主要系统群之间的关系，以了解各分支起源的地理区域和历史范围扩展的可能方向。在高地和低地发现了由线粒体单倍型分支所诊断的独特的种内谱系。这些系统群之间的大多数地理边界与河流并不一致，这表明河流对系统群主要分化的影响在这些青蛙中可能很小。然而，我们发现了一个低地物种复合体受到河流阻隔影响的证据，其中最重要的遗传不连续（Heterixalus Madagascariensis和H. Alboguttus之间的边界）与马达加斯加中东海岸Mango河的地理位置一致。对高地物种H. betsileo的分析表明，存在六个深单倍型谱系，分为两个主要亚群，在海拔分布上差异很大，与高地河流的地理环境不重叠。此外，我们的分析表明，大多数主要的芦苇蛙种内谱系都显示出最近种群扩张的迹象。

参考文献：

Gehring, PS, Pabijan M, Randrianirina JE, Glaw F, Vences M. 2012. The influence of riverine barriers on phylogeographic patterns of Malagasy reed frogs ( Heterixalus ) [J]. Molecular Phylogenetics & Evolution, 64(3): 618-632.