High degree of cryptic population differentiation in the Baltic Sea herring Clupea harengus
High degree of cryptic population differentiation in the Baltic Sea herring Clupea harengus
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DOI：
10.1111/mec.12174
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发表时间：
2013-06-01
影响因子：
4.9
通讯作者：
Merila, Juha
中科院分区：
文献类型：
--
作者：
Corander, Jukka;Majander, Kerttu K.;Merila, Juha
海洋鱼类的特点是在假定的中性标记基因上种群分化程度较低。传统上，这归因于生态同质性和海洋生境缺乏明显的扩散障碍，以及大多数海洋鱼类的（有效）种群规模较大。鲱鱼 (Clupea harengus) 就是一个很好的例子 - 即使在广阔的地理区域，中性标记处的种群分化水平通常也非常低（FST 大约为 0.005）。我们使用 RAD 测序方法鉴定了鲱鱼中的 5985 个新型单核苷酸多态性标记 (SNP)，并使用相距 387 公里的两个波罗的海种群之间的混合 DNA 样本估计了全基因组的差异水平。我们发现人群之间总共有 4756 个不同的 SNP（占所有 SNP 的 79%），其中 117 个显示出显着差异的证据，在考虑了由于次要等位基因和混合样本中 DNA 扩增不均匀而可能产生的偏差后，对应于 FST=0.128（0.125，0.131）。这一估计——基于对许多基因组多态性的筛选——表明在这种具有重要商业价值的物种中存在迄今为止未被认识的遗传分化水平，挑战了海洋鱼类遗传同质性的观点，特别是波罗的海鲱鱼的遗传同质性观点。
Marine fish species are characterized by a low degree of population differentiation at putatively neutral marker genes. This has been traditionally attributed to ecological homogeneity and a lack of obvious dispersal barriers in marine habitats, as well as to the large (effective) population sizes of most marine fish species. The herring (Clupea harengus) is a case in point - the levels of population differentiation at neutral markers, even across vast geographic areas, are typically very low (FST approximate to 0.005). We used a RAD-sequencing approach to identify 5985 novel single-nucleotide polymorphism markers (SNPs) in herring and estimated genome-wide levels of divergence using pooled DNA samples between two Baltic Sea populations separated by 387km. We found a total of 4756 divergent SNPs (79% of all SNPs) between the populations, of which 117 showed evidence of substantial divergence, corresponding to FST=0.128 (0.125, 0.131) after accounting for possible biases due to minor alleles and uneven DNA amplification over the pooled samples. This estimate - based on screening many genomic polymorphisms - suggests the existence of hitherto unrecognized levels of genetic differentiation in this commercially important species, challenging the view of genetic homogeneity in marine fish species, and in that of the Baltic Sea herring in particular.