Adaptive introgression of a visual preference gene.

Abstract

Visual preferences are important drivers of mate choice and sexual selection, but little is known of how they evolve at the genetic level. In this study, we took advantage of the diversity of bright warning patterns displayed by <i>Heliconius</i> butterflies, which are also used during mate choice. Combining behavioral, population genomic, and expression analyses, we show that two <i>Heliconius</i> species have evolved the same preferences for red patterns by exchanging genetic material through hybridization. Neural expression of <i>regucalcin1</i> correlates with visual preference across populations, and disruption of <i>regucalcin1</i> with CRISPR-Cas9 impairs courtship toward conspecific females, providing a direct link between gene and behavior. Our results support a role for hybridization during behavioral evolution and show how visually guided behaviors contributing to adaptation and speciation are encoded within the genome.