Ovine ELOVL5 and FASN genes polymorphisms and their correlations with sheep tail fat deposition

•Both ELOVL5 and FASN genes was associated with the traits of tail fat deposition.•ELOVL5 and FASN expression levels were highest in tail fat.•ELOVL5 expression levels in the big-tail group were highest.•The expression of FASN in small-tail group were highest.•ELOVL5 and FASN have the highest expression at 6 months and 3 months of age. Reducing tail fat deposition can increase the economic value of a carcass and improve feed efficiency. This study aimed to explore ELOVL5 and FASN polymorphisms associated with tail fat deposition and their expression levels of sheep. Association analysis showed that ELOVL5 synonymous mutation g.62534 C > T was associated with tail width, tail fat weight, and relative tail fat weight (P G was associated with tail length and width (P