CYP2J19 mediates carotenoid colour introgression across a natural avian hybrid zone

Abstract

This a preprint and has not been peer reviewed. Data may be preliminary.

Extensive hybridization reveals multiple coloration genes underlying a complex plumage phenotype

“…CYP2J19 upregulation via an introgressed variant is causal in changing the typical yellow-feathered canary (Serinus canaria) into the "red factor" canary6 and the lack of a functional copy in zebra finch (Taeniopygia guttata) is implicated in the "yellowbeak" phenotype in which the normally red beak and legs are instead yellow42. It is currently one of only two genes known to be involved in red coloration in birds, but evidence of its functioning in natural systems is still limited (but see [43][44][45]. Our identification of CYP2J19 in the GWA for wings and tail coloration suggests that it mediates this yellow versus red trait difference in flickers and provides further support for its importance in red coloration across diverse avian lineages.…”

Taxonomic revision of the Red-fronted Tinkerbird Pogoniulus pusillus (Dumont, 1816) based on molecular and phenotypic analyses

“…On the other hand, genetic divergence either side of Kilifi Creek is unexpected, and studies are ongoing to determine if there is gene flow between these forms (ANGK unpubl.). Tinkerbirds in this complex have been shown to hybridise, with P. p. pusillus and P. c. extoni interbreeding freely in their 50-100 km-wide contact zone in southern Africa (Nwankwo et al 2019, Kirschel et al 2020a, and introgressive hybridisation between the more closely related and phenotypically similar eupterus and affinis would not be unexpected if they do indeed come into contact.…”

“…© 2021 The Authors; This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ISSN-2513-9894 (Online) estimated a Tobias et al (2010) score of 8, based on low effect sizes for morphometric (1) and song differences (1), 3 for plumage, based on the distinct forecrown colour difference(Nwankwo et al 2019, Kirschel et al 2020a), 1 for ecology, based on differences in their preferred habitats, savanna woodland (P. chrysoconus) vs. forest (P. pusillus)(Short & …”

Full Issue

“…Red-fronted Tinkerbird had been distinguished from its presumed sister taxon, Yellowfronted Tinkerbird P. chrysoconus, primarily using plumage differences, most notably forecrown colour. It is most parsimonious for a derived trait, such as the red forecrown colour, to have evolved once, but with the red forecrown feathers in this species explained by a gene that converts yellow dietary carotenoids to red ketocarotenoids (Kirschel et al 2020a), it is possible that homoplasy, wherein different mutations lead to a convergent phenotype, explains such parallel patterns. It is therefore possible that disjunct populations of tinkerbirds with red forecrowns have resulted from independent mutations among genes functioning in the conversion of carotenoids.…”