Multilocus phylogeny and cryptic diversity of white-toothed shrews (Mammalia, Eulipotyphla, Crocidura) in China
Multilocus phylogeny and cryptic diversity of white-toothed shrews (Mammalia, Eulipotyphla, Crocidura) in China
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DOI：
10.1186/s12862-020-1588-8
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发表时间：
2020-02-14
影响因子：
3.4
通讯作者：
Liu, Shaoying
中科院分区：
文献类型：
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作者：
Chen, Shunde;Qing, Jiao;Liu, Shaoying
背景 鳄鱼属是最特殊的哺乳动物属，分布在亚洲、欧洲和非洲的大部分地区。中国代表的分类学主要基于粗略的形态学比较来研究，其分子系统发育分析仍有待探索。为了了解中国该类群的系统发育，我们估计了第一个多位点系统发育并进行了物种定界，包括在整个分布范围内进行分类单元采样。结果我们从57个地点的132个样本中获得了1个线粒体基因（cytb）（1, 134 bp）和3个核基因（ApoB、BRCA1、RAG1）（2, 170 bp）。分子分析确定了至少 14 种假定的物种，它们存在于中国两个得到充分支持的主要类群中。多系 C. wuchihensis 似乎由两个假定的物种组成。两个亚种，C. rapax rapax 和 C. rapax kurodai 应该提升到完整物种状态。基于亚洲 Crocidura 物种线粒体基因的系统发育树表明，C. rapax rapax 嵌入 C. attenuata 中，使后者成为并系群。三个强烈支持的未描述物种（C. sp.1、C. sp.2 和 C. sp.3）分别来自西藏扎达县（中国西部）、湖南省洪江县（中国中部）、浙江省东阳县（中国东部）和西藏墨脱县。分化时间估计表明，中国鳄鱼物种在上新世晚期（3.66 Ma）和早更新世（2.29 Ma）开始多样化，随后在更新世发生了一系列多样化。结论 本研究中发现的神秘多样性表明，在当前分类法下，物种数量被严重低估。我们建议应该使用广泛的分类采样和综合形态学和形态测量方法来评估这三个未描述的物种。上新世晚期以来的气候变化和青藏高原的隆起可能导致中国鳄鱼物种的多样化和物种形成。简而言之，被低估的多样性凸显了对中国鳄鱼物种进行分类学修订的必要性。
Background Crocidura, the most speciose mammalian genus, occurs across much of Asia, Europe and Africa. The taxonomy of Chinese representatives has been studied primarily based on cursory morphological comparisons and their molecular phylogenetic analyses remain unexplored. In order to understand the phylogeny of this group in China, we estimated the first multilocus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. Results We obtained one mitochondrial gene (cytb) ( 1, 134 bp) and three nuclear genes (ApoB, BRCA1, RAG1) ( 2, 170 bp) for 132 samples from 57 localities. Molecular analyses identified at least 14 putative species that occur within two major well-supported groups in China. Polyphyletic C. wuchihensis appears to be composed of two putative species. Two subspecies, C. rapax rapax and C. rapax kurodai should be elevated to full species status. A phylogenetic tree based on mitochondrial gene from Asian Crocidura species showed that the C. rapax rapax is embedded within C. attenuata, making the latter a paraphyletic group. Three strongly supported undescribed species (C. sp.1, C. sp.2 and C. sp.3) are revealed from Zada County of Tibet (Western China), Hongjiang County of Hunan Province (Central China) and Dongyang County of Zhejiang Province (Eastern China), Motuo County of Tibet, respectively. The divergence time estimation suggested that China's Crocidura species began to diversify during the late Pliocene (3.66 Ma) and the Early Pleistocene (2.29 Ma), followed by a series of diversifications through the Pleistocene. Conclusions The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. We propose that the three undescribed species should be evaluated using extensive taxon sampling and comprehensive morphological and morphometric approaches. Climate change since the late Pliocene and the uplift of the Qinghai-Tibet Plateau may result in the diversification and speciation of China's Crocidura species. In short, the underestimated diversity underlines the need for a taxonomic revision of Chinese Crocidura species.