RT Journal Article
SR Electronic
T1 The genomic basis of colour pattern polymorphism in the harlequin ladybird
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 345942
DO 10.1101/345942
A1 Mathieu Gautier
A1 Junichi Yamaguchi
A1 Julien Foucaud
A1 Anne Loiseau
A1 Aurélien Ausset
A1 Benoit Facon
A1 Bernhard Gschloessl
A1 Jacques Lagnel
A1 Etienne Loire
A1 Hugues Parrinello
A1 Dany Severac
A1 Celine Lopez-Roques
A1 Cecile Donnadieu
A1 Maxime Manno
A1 Helene Berges
A1 Karim Gharbi
A1 Lori Lawson-Handley
A1 Lian-Sheng Zang
A1 Heiko Vogel
A1 Arnaud Estoup
A1 Benjamin Prud’homme
YR 2018
UL http://biorxiv.org/content/early/2018/06/13/345942.abstract
AB Many animal species are comprised of discrete phenotypic forms. Understanding the genetic mechanisms generating and maintaining such phenotypic variation within species is essential to comprehending morphological diversity. A common and conspicuous example of discrete phenotypic variation in natural populations of insects is the occurrence of different colour patterns, which has motivated a rich body of ecological and genetic research1–6. The occurrence of dark, i.e. melanic, forms, displaying discrete colour patterns, is found across multiple taxa, but the underlying genomic basis remains poorly characterized. In numerous ladybird species (Coccinellidae), the spatial arrangement of black and orange patches on adult elytra varies wildly within species, forming strikingly different complex colour patterns7,8. In the harlequin ladybird Harmonia axyridis, more than 200 distinct colour forms have been described, which classic genetic studies suggest result from allelic variation at a single, unknown, locus9,10. Here, we combined whole-genome sequencing, population genomics, gene expression and functional analyses, to establish that the gene pannier controls melanic pattern polymorphism in H. axyridis. We show that pannier, which encodes an evolutionary conserved transcription factor, is necessary for the formation of melanic elements on the elytra. Allelic variation in pannier leads to protein expression in distinct domains on the elytra, and thus determines the distinct colour patterns in H. axyridis. Recombination between pannier alleles may be reduced by a highly divergent sequence of ca. 170 kb in the cis-regulatory regions of pannier with a 50 kb inversion between colour forms. This likely helps maintaining the distinct alleles found in natural populations. Thus we propose that highly variable discrete colour forms can arise in natural populations through cis-regulatory allelic variation of a single gene.