Asgharian Hosseinali, Chang Peter L, Lysenkov Sergey, Scobeyeva Victoria A, Reisen William K, Nuzhdin Sergey V
Program in Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
Program in Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA Department of Evolution, Moscow State University, Moscow 119991, Russia.
Proc Biol Sci. 2015 Jul 7;282(1810). doi: 10.1098/rspb.2015.0728.
We present the first genome-wide study of recent evolution in Culex pipiens species complex focusing on the genomic extent, functional targets and likely causes of global and local adaptations. We resequenced pooled samples of six populations of C. pipiens and two populations of the outgroup Culex torrentium. We used principal component analysis to systematically study differential natural selection across populations and developed a phylogenetic scanning method to analyse admixture without haplotype data. We found evidence for the prominent role of geographical distribution in shaping population structure and specifying patterns of genomic selection. Multiple adaptive events, involving genes implicated with autogeny, diapause and insecticide resistance were limited to specific populations. We estimate that about 5-20% of the genes (including several histone genes) and almost half of the annotated pathways were undergoing selective sweeps in each population. The high occurrence of sweeps in non-genic regions and in chromatin remodelling genes indicated the adaptive importance of gene expression changes. We hypothesize that global adaptive processes in the C. pipiens complex are potentially associated with South to North range expansion, requiring adjustments in chromatin conformation. Strong local signature of adaptation and emergence of hybrid bridge vectors necessitate genomic assessment of populations before specifying control agents.
我们展示了对尖音库蚊复合种近期进化的首次全基因组研究，重点关注全球和局部适应的基因组范围、功能靶点及可能原因。我们对尖音库蚊六个种群和外群溪流库蚊两个种群的混合样本进行了重测序。我们使用主成分分析系统地研究不同种群间的差异自然选择，并开发了一种系统发育扫描方法来分析无单倍型数据的混合情况。我们发现有证据表明地理分布在塑造种群结构和确定基因组选择模式方面发挥着重要作用。涉及与自体繁殖、滞育和抗杀虫剂相关基因的多个适应性事件仅限于特定种群。我们估计每个种群中约5 - 20%的基因（包括几个组蛋白基因）和近一半的注释通路正在经历选择性清除。非基因区域和染色质重塑基因中频繁出现的清除表明基因表达变化具有适应性重要性。我们推测尖音库蚊复合种中的全球适应性过程可能与从南到北的范围扩张有关，这需要染色质构象的调整。强烈的局部适应特征和杂交桥梁媒介种群的出现使得在确定控制媒介之前有必要对种群进行基因组评估。
