GBS Data Identify Pigmentation-Specific Genes of Potential Role in Skin-Photosensitization in Two Tunisian Sheep Breeds
by
, ,
Imen Baazaoui
1, 
John McEwan
2,
Rayna Anderson
2,
Rudiger Brauning
2,
Alan McCulloch
2,
Tracey Van Stijn
2 and
Sonia Bedhiaf-Romdhani
3,* 1
Faculty of Science of Bizerte, University of Carthage, Carthage 1054, Tunisia
2
AgResearch Ltd., Invermay Agricultural Centre; Mosgiel 9092, New Zealand
3
National Agricultural Research Institute of Tunisia, Laboratory of Animal and forage Production, University of Carthage, Ariana 1004, Tunisia
*
Author to whom correspondence should be addressed.
Animals 2020, 10(1), 5; https://doi.org/10.3390/ani10010005
Submission received: 7 November 2019
/
Revised: 9 December 2019
/
Accepted: 11 December 2019
/
Published: 18 December 2019
(This article belongs to the Special Issue Morpho-Functional and Genetic Characterization of Local Breeds)
Simple Summary
Maintaining the flexibility of the genetic resources of native animals to face local environment constraints is still a major challenge. In Tunisia, the Noire de Thibar breed is a local sheep, typically with black coloration, known for its ability to tolerate “hypericum perforatum”, which causes skin photosensitization in white colored sheep. The goal of this study was to perform a genome scan, by considering genotyping-by-sequencing (GBS) markers that were genotyped in divergent coat colored sheep (black vs. white) to identify strong, and recent, artificial selection that is involved in skin-photosensitization. Interestingly, the genomic differentiation analysis identified FST markers within genomic regions containing key pigmentation and photosensitivity related-genes. These findings help in understanding the background of coat color genetics and its potential role in adaptation to local environment constraints.
Abstract
The Tunisian Noire de Thibar sheep breed is a composite breed, recently selected to create animals that are uniformly black in order to avoid skin photosensitization after the ingestion of toxic “hypericum perforatum” weeds, which causes a major economic loss to sheep farmers. We assessed genetic differentiation and estimated marker FST using genotyping-by-sequencing (GBS) data in black (Noire de Thibar) and related white-coated (Queue fine de l’ouest) sheep breeds to identify signals of artificial selection. The results revealed the selection signatures within candidate genes related to coat color, which are assumed to be indirectly involved in the mechanism of photosensitization in sheep. The identified genes could provide important information for molecular breeding.
