Population genomics of parallel hybrid zones in the mimetic butterflies, H. melpomene and H. erato

Hybrid zones can be valuable tools for studying evolution and identifying genomic regions responsible for adaptive divergence and underlying phenotypic variation. Hybrid zones between subspecies of Heliconius butterflies can be very narrow and are maintained by strong selection acting on colour pattern. The co-mimetic species H. erato and H. melpomene have parallel hybrid zones where both species undergo a change from one colour pattern form to another. We use restriction associated DNA sequencing to obtain several thousand genome wide sequence markers and use these to analyse patterns of population divergence across two pairs of parallel hybrid zones in Peru and Ecuador. We compare two approaches for analysis of this type of data; alignment to a reference genome and de novo assembly, and find that alignment gives the best results for species both closely (H. melpomene) and distantly (H. erato, ~15% divergent) related to the reference sequence. Our results confirm that the colour patter...

杂交带（hybrid zone）是开展演化研究、识别适应性分化相关基因组区域以及潜在表型变异的重要工具。袖蝶属（Heliconius）蝴蝶不同亚种间形成的杂交带通常极为狭窄，且由作用于体色图案的强烈选择压力所维持。协同拟态的H. erato与H. melpomene拥有平行杂交带，两个物种均在此类区域中完成从一种体色图案型向另一种的转变。本研究采用限制性位点关联DNA测序（restriction site-associated DNA sequencing，RAD-seq）技术获取了数千个全基因组范围的序列标记，以此分析秘鲁与厄瓜多尔境内两对平行杂交带的种群分化模式。我们对比了针对此类数据的两种分析方法：参考基因组比对（alignment to a reference genome）与从头组装（de novo assembly），结果显示，无论对于与参考序列亲缘关系较近的H. melpomene，还是亲缘关系较远（与参考序列分化度约15%）的H. erato，参考基因组比对法均能获得最优结果。本研究结果证实，体色图案相关的[原文内容未完整呈现]