Phylogenomic analyses reveal latitudinal population structure and polymorphisms in heat stress genes in the North Atlantic snail Nucella lapillus
Phylogenomic analyses reveal latitudinal population structure and polymorphisms in heat stress genes in the North Atlantic snail Nucella lapillus
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DOI：
10.1111/mec.12681
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发表时间：
2014-04-01
影响因子：
4.9
通讯作者：
Vollmer, Steven V.
中科院分区：
文献类型：
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作者：
Chu, Nathaniel D.;Kaluziak, Stefan T.;Vollmer, Steven V.
北大西洋岩石潮间带物种已形成的重复冰川和强烈的纬度温度梯度，使他们成为一个很好的系统，研究冰后期的地理和耐热性。然而，来自西北大西洋物种的群体遗传学数据往往显示出与预测不一致的模式，即高扩散应该在群体之间产生较弱的遗传结构。在这里，我们使用下一代测序限制相关的DNA标签（RAD-seq）和从RNA-seq数据组装的转录组来分析低分散潮间带蜗牛Nucella lapillus西北大西洋种群的遗传结构。虽然以前在这一地区的研究几乎没有发现在N.lapillus的遗传结构，我们的基因组方法确定了一个良好的支持分裂之间的北方和南方的分支。通过比较RAD-seq数据和我们的转录组组装，我们在这些纬度分支之间确定了数千个固定的单核苷酸多态性（SNP），这些SNP映射到蛋白质编码基因，包括与热应激耐受性相关的基因。这些固定的SNPs可能代表在大西洋西北部不同的热制度下选择的基因座。
North Atlantic rocky intertidal species have been shaped by repeated glaciations and strong latitudinal temperature gradients, making them an excellent system to study postglacial phylogeography and thermal tolerance. Population genetics data from northwestern Atlantic species, however, often show patterns inconsistent with the prediction that high dispersal should generate weaker genetic structure among populations. Here, we used next-generation sequencing restriction-associated DNA tags (RAD-seq) and a transcriptome assembled from RNA-seq data to analyse the genetic structure of northwestern Atlantic populations of the low-dispersal intertidal snail Nucella lapillus. Although previous studies in this region have detected almost no genetic structure in N.lapillus, our phylogenomic approach identified a well-supported split between northern and southern clades. By comparing RAD-seq data and our transcriptome assembly, we identified thousands of fixed single-nucleotide polymorphisms (SNPs) between these latitudinal clades that map to protein-coding genes, including genes associated with heat stress tolerance. These fixed SNPs might represent loci under selection for different thermal regimes in the northwestern Atlantic.