Genome-wide identification of the mutation underlying fleece variation and discriminating ancestral hairy species from modern woolly sheep.

Authors: Demars, Julie and Cano, Margarita and Drouilhet, Laurence and Plisson-Petit, Florence and Bardou, Philippe and Fabre, Stéphane and Servin, Bertrand and Sarry, Julien and Woloszyn, Florent and Mulsant, Philippe and Foulquier, Didier and Carrière, Fabien and Aletru, Mathias and Rodde, Nathalie and Cauet, Stéphane and Bouchez, Olivier and Pirson, Maarten and Tosser-Klopp, Gwenola and Allain, Daniel

The composition and structure of fleece variation observed in mammals is a consequence of a strong selective pressure for fiber production after domestication. In sheep, fleece variation discriminates ancestral species carrying a long and hairy fleece from modern domestic sheep (Ovis aries) owning a short and woolly fleece. Here, we report that the "woolly" allele results from the insertion of an antisense EIF2S2 retrogene (called asEIF2S2) into the 3' UTR of the IRF2BP2 gene leading to an abnormal IRF2BP2 transcript. We provide evidence that this chimeric IRF2BP2/asEIF2S2 messenger 1) targets the genuine sense EIF2S2 RNA and 2) creates a long endogenous double-stranded RNA which alters the expression of both EIF2S2 and IRF2BP2 mRNA. This represents a unique example of a phenotype arising via a RNA-RNA hybrid, itself generated through a retroposition mechanism. Our results bring new insights on the sheep population history thanks to the identification of the molecular origin of an evolutionary phenotypic variation.© The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Journal: Molecular biology and evolution
DOI: 10.1093/molbev/msx114
Year: 2017

Read publication