A Single Nucleotide Polymorphism in the WIF1 Promoter Region Regulates the Wool Length in Rabbits

Abstract

Wool length is an important trait in the rabbit wool industry. Wnt inhibitory factor 1 (WIF1), a key gene, regulates hair follicle growth and development. This study explores the WIF1 gene relationship with wool production traits in three different rabbit breeds, Rex rabbit, New Zealand rabbit, and Angora rabbit. The rabbit WIF1 gene sequence was obtained from GenBank, and PCR and Sanger sequencing were applied to screen SNP (single nucleotide polymorphism) from the gene exons and promoter regions. Sequencing results found no SNP in the PCR products of 10 exons from the rabbit WIF1 gene, indicating that the WIF1 gene was not polymorphic. Thus, the gene was conserved in all three rabbit breeds. Only one SNP was found in the WIF1 promoter region, associated with wool-producing traits in rabbits. Luciferase activity assays showed that the AA genotype had higher transcriptional activities than the AG or GG genotype (p < 0.01). In addition, WIF1 was significantly upregulated in the Rex rabbit compared to the New Zealand rabbit and Angora rabbit (p < 0.01). In summary, a key SNP in the WIF1 promoter region was found to be associated with rabbit fiber length trait.