Lineage diversity and gene introgression in freshwater cladoceran crustaceans of the Chydorus sphaericus species complex
Lineage diversity and gene introgression in freshwater cladoceran crustaceans of the Chydorus sphaericus species complex
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DOI：
10.1002/lno.11590
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发表时间：
2020-09
影响因子：
4.5
通讯作者：
Jinhui Wang;Yijun Ni;Wei Hu;Mingbo Yin
中科院分区：
文献类型：
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作者：
Jinhui Wang;Yijun Ni;Wei Hu;Mingbo Yin
古北界东部水生无脊椎浮游动物的遗传多样性和种群地理学研究日益受到人们的关注，但在我国尚处于探索阶段。在这里，我们调查了一个重要的枝角类分类群的谱系多样性和生态地理，Chydorus sphaericus（甲壳纲：枝角类）物种复合体，这是常见的各种水生栖息地。我们在中国154个水体中的30个水体中发现了这种复合体的种群。从线粒体细胞色素c氧化酶亚基I基因的一部分的DNA序列分析将这些人口在三个谱系，其中一个以前没有认识到。C有明显的地理分隔。sphaericus谱系：谱系A2 - 1是在青藏高原检测到的唯一谱系，而谱系A3 - 1和A3 - 2存在于中国其他地方。几个谱系（甚至是单个单倍型）在欧亚大陆广泛分布，表明它们具有长距离传播的能力。基于核核糖体内转录间隔区片段（ITS-1和ITS-2）的系统发育识别出两种不同的C. sphaericus分支。有趣的是，一个具有线粒体谱系A3 - 2的样本被意外地发现具有通常与线粒体谱系A2 - 1相关的ITS-1等位基因，并且ITS-2等位基因与此一致。线粒体DNA和核同源性之间的这种不一致性表明了种间杂交和物种复合体不同成员之间的基因渐渗。本研究有助于了解中国对虾的遗传多样性。sphaericus物种复杂的欧亚背景。
There is increasing interest in the genetic diversity and phylogeography of aquatic invertebrate zooplankton in the Eastern Palearctic, yet these topics remain largely unexplored in China. Here, we investigated the lineage diversity and phylogeography of an important cladoceran taxon, the Chydorus sphaericus (Crustacea: Cladocera) species complex, which is common in various aquatic habitats. We found populations of this species complex in 30 of 154 waterbodies across China. Analysis of DNA sequences from a portion of the mitochondrial cytochrome c oxidase subunit I gene placed these populations in three lineages, one of them not previously recognized. There was a clear geographical separation of C. sphaericus lineages: lineage A2‐1 was the only lineage detected on the Qinghai‐Tibetan Plateau, whereas lineages A3‐1 and A3‐2 were present elsewhere in China. Several lineages (and even individual haplotypes) were widespread in Eurasia, suggesting an ability to disperse over long distances. Phylogenies based on nuclear ribosomal internal transcribed spacer fragments (both ITS‐1 and ITS‐2) recognized two distinct C. sphaericus clades in China. Interestingly, one specimen possessing mtDNA of lineage A3‐2 was found unexpectedly to have an ITS‐1 allele normally associated with mitochondrial lineage A2‐1, and ITS‐2 alleles consistent with this. This discordance between mtDNA and nuclear phylogenies is indicative of interspecific hybridization and gene introgression between different members of the species complex. This study contributes to an understanding of the genetic diversity of the C. sphaericus species complex in a Eurasian context.