Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY.
Mol Biol Evol. 2019 Jan 1;36(1):159-173. doi: 10.1093/molbev/msy209.
Cis-regulatory evolution is an important engine of organismal diversification. Although recent studies have looked at genomic patterns of regulatory evolution between species, we still have a poor understanding of the magnitude and nature of regulatory variation within species. Here, we examine the evolution of regulatory element activity over wing development in three Heliconius erato butterfly populations to determine how regulatory variation is associated with population structure. We show that intraspecific divergence in chromatin accessibility and regulatory activity is abundant, and that regulatory variants are spatially clustered in the genome. Regions with strong population structure are highly enriched for regulatory variants, and enrichment patterns are associated with developmental stage and gene expression. We also found that variable regulatory elements are particularly enriched in species-specific genomic regions and long interspersed nuclear elements. Our findings suggest that genome-wide selection on chromatin accessibility and regulatory activity is an important force driving patterns of genomic divergence within Heliconius species. This work also provides a resource for the study of gene regulatory evolution in H. erato and other heliconiine butterflies.
顺式调控进化是生物多样化的重要引擎。尽管最近的研究已经研究了物种之间调控进化的基因组模式，但我们仍然对物种内调控变异的程度和性质知之甚少。在这里，我们研究了三个海伦娜凤蝶种群的翅膀发育过程中调控元件活性的进化，以确定调控变异与种群结构的关系。我们发现，染色质可及性和调控活性的种内差异非常丰富，并且调控变体在基因组中呈空间聚集。具有强烈种群结构的区域富含调控变体，富集模式与发育阶段和基因表达有关。我们还发现，可变调控元件在物种特异性基因组区域和长散布核元件中特别丰富。我们的研究结果表明，对染色质可及性和调控活性的全基因组选择是驱动海伦娜凤蝶物种内基因组分化模式的重要力量。这项工作还为研究 H. erato 和其他凤蝶科蝴蝶的基因调控进化提供了资源。
