Animal and Plant Sciences, The University of Sheffield, Western Bank, Sheffield, UK.
J Evol Biol. 2010 Sep 1;23(9):2004-16. doi: 10.1111/j.1420-9101.2010.02071.x. Epub 2010 Jul 31.
Genome scans have been used in the studies of ecological speciation to find genomic regions ('outlier loci') showing reduced gene flow between divergent populations/species. High-throughput sequencing ('454') offers new opportunities in this field via transcriptome sequencing. Divergent ecotypes of the marine gastropod Littorina saxatilis represent a good example of incipient ecological speciation. We performed a 454-based genome scan between H and M ecotypes of L. saxatilis from the British Isles using cDNA of pooled individuals. Allele frequencies were calculated for 2454 single nucleotide polymorphisms (SNPs), within 572 contigs, and 7% of loci were detected as outliers. Functional annotation of the contigs containing outlier SNPs showed that they included shell matrix and muscle proteins (lithostathine, mucin, titin), proteins involved in energetic metabolism (arginine kinase, NADH dehydrogenase) and reverse transcriptases. Follow-up investigations into these proteins and unannotated outliers will be a promising route in the study of ecological speciation in L. saxatilis.
基因组扫描已被用于生态物种形成的研究中，以寻找显示出在不同种群/物种之间基因流动减少的基因组区域（“异常基因座”）。高通量测序（“454”）通过转录组测序为该领域提供了新的机会。海洋腹足纲蜗牛 Littorina saxatilis 的不同生态型是初生生态物种形成的一个很好的例子。我们使用来自不列颠群岛的 H 和 M 生态型 Littorina saxatilis 的个体混合 cDNA ，在基于 454 的基因组扫描中进行了研究。在 572 个连续序列中，计算了 2454 个单核苷酸多态性（SNP）的等位基因频率，其中 7%的基因座被检测为异常。包含异常 SNP 的连续序列的功能注释表明，它们包括壳基质和肌肉蛋白（石纹蛋白、粘蛋白、原肌球蛋白）、参与能量代谢的蛋白质（精氨酸激酶、NADH 脱氢酶）和逆转录酶。对这些蛋白质和未注释的异常基因座的后续研究将是研究 Littorina saxatilis 生态物种形成的一个有前途的途径。
