Genetics of continuous colour variation in a pair of sympatric sulphur butterflies

• DOI: 10.1101/2023.02.03.526907
• Publication Date: 2023-02-05T05:45:20Z
• Authors: Joseph J. Hanly; Caroline M. Franc...; Ling S. Loh; Olaf B. W. H. Cor...; Derek J. Long; Marshall A Nakatani; Adam H. Porter; Arnaud Martin
• Keywords: Genetic architecture; Candidate gene

Summary Continuous colour polymorphisms can serve as a tractable model for the genetic and developmental architecture of traits, but identification causative loci is complex due to number individuals needed, challenges scoring continuously varying traits. Here we investigated continuous variation in Colias eurytheme C. philodice , two sister species sulphur butterflies that hybridise sympatry. Using Quantitative Trait Locus (QTL) analysis 483 from interspecific crosses an high-throughput method quantification, found interacting large effect explain around 70% heritable orange-to-yellow chromaticity. Knockouts red Malphighian tubules ( ), candidate gene at primary QTL likely involved endosomal maturation, resulted depigmented wing scales showing disorganised pterin granules. The Z sex chromosome contains secondary includes transcription factor bric-a-brac bab which show act modulator orange pigmentation addition its previously-described role specifying UV-iridescence. We also describe other size maps chromosome, supporting Large-X where control species-defining traits enriched on chromosomes. This study sheds light trait, illustrates power using automated measurement score phenotypes are not always conspicuous human eye. Foreword this article involve nuanced gradations yellow may be difficult perceive people who vision deficient. Hue-shifted versions all main figures accessible online dichromat readers (BioRxiv preprint: Supplementary Material).