Deletion of an Enhancer in FGF5 is Associated With Ectopic Expression in Goat Hair Follicles and the Cashmere Growth Phenotype

Abstract BackgroundResearch on cashmere growth has a significant effect on the production of cashmere and a profound influence on cashmere goat breeding. Whole-genome sequencing is a powerful platform to rapidly gain novel insights into the identification of genetic mechanisms underlying cashmere fiber growth. ResultsIn this study, we generated whole-genome sequences of 115 domestic goats from China, Nepal and Pakistan, including 51 cashmere goats and 64 non-cashmere goats. We found genetically distinct clusters according to their geographic locations but genetic admixture or introgression may have occurred between the Chinese and Nepalese goats. We identified that the fibroblast growth factor 5 gene (FGF5) shows a strong signature for positive selection in the cashmere goat. The 505-bp indel variant at the FGF5 gene locus appeared to be strongly associated with cashmere growth. Functional validation showed that the insertion variant may serve as an enhancer for transcription factor binding, resulting in increased transcription of the upstream FGF5 gene in non-cashmere goats. ConclusionsOur study provides useful information for the sustainable utilization and improved conservation of goat genetic resources and demonstrates that the indel mutation in the FGF5 gene could potentially serve as a molecular marker of cashmere growth in cashmere goat breeding.