A genetic mechanism for sexual dichromatism in birds

Many animals are sexually dimorphic, with different phenotypes in males and females. To identify the genetic basis of sexual differences in bird coloration, Gazda et al. (2020) investigated red coloration in mosaic canaries and related species. Using a combination of genetic crosses, genomic mapping, transcriptomics, and comparative analyses, the authors show that trans-regulation of the carotenoid-processing gene BCO2 is involved in sexual dichromatism. Photo by Ricardo J Lopes.