Discovery of SNPs in RXFP2 related to horn types in sheep

This study was conducted with an attempt to reveal genetic variation in ovine RXFP2, which is a strong candidate gene that is associated with sheep horn development and types. All 18 exons and intro-exon boundary regions as well as 5′ and 3′ gene flanking regions of RXFP2 were re-sequenced using DNA panels representing four typical horn types (normal-horned males, normal-horned females, scurred females, and polled females) in Tan sheep, as well as the DNA pools from Suffolk, a polled sheep breed. A total of 20 previously unreported SNPs were detected. One in the 5′UTR, four in exons, and 15 in the introns. Seven of the 20 SNPs were species-specific variants. A synonymous mutation, p.P375 (c.1125A>G), demonstrating distinct genotypes between horned and hornless individuals, which is located in a conserved region, was regarded as a candidate variant indicating the appearance or absence of horns in sheep.