RESUMO

Little is known about the extent to which species use homologous regulatory architectures to achieve phenotypic convergence. By characterizing chromatin accessibility and gene expression in developing wing tissues, we compared the regulatory architecture of convergence between a pair of mimetic butterfly species. Although a handful of color pattern genes are known to be involved in their convergence, our data suggest that different mutational paths underlie the integration of these genes into wing pattern development. This is supported by a large fraction of accessible chromatin being exclusive to each species, including the de novo lineage-specific evolution of a modular optix enhancer. These findings may be explained by a high level of developmental drift and evolutionary contingency that occurs during the independent evolution of mimicry.

Assuntos

Evolução Biológica , Mimetismo Biológico , Borboletas , Montagem e Desmontagem da Cromatina , Asas de Animais , Animais , Mimetismo Biológico/genética , Borboletas/anatomia & histologia , Borboletas/genética , Borboletas/crescimento & desenvolvimento , Pigmentação/genética , Asas de Animais/anatomia & histologia , Asas de Animais/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Elementos Facilitadores Genéticos

RESUMO

Identifying the genomic changes that control morphological variation and understanding how they generate diversity is a major goal of evolutionary biology. In Heliconius butterflies, a small number of genes control the development of diverse wing color patterns. Here, we used full genome sequencing of individuals across the Heliconius erato radiation and closely related species to characterize genomic variation associated with wing pattern diversity. We show that variation around color pattern genes is highly modular, with narrow genomic intervals associated with specific differences in color and pattern. This modular architecture explains the diversity of color patterns and provides a flexible mechanism for rapid morphological diversification.