Abstract

Black coat color in pigs is determined by the dominantEallele at theMC1Rlocus. Through comparingMC1Rgene sequences between recessiveeand dominantED1alleles, we identified four missense mutations that could affect MC1R protein function for eumelanin synthesis. With the aim of devising a genetic modification method for pig coat color manipulation, we mutated theeallele in the Duroc breed to the dominantED1allele using CRISPR-mediated homologous recombination for the four mutation substitutions at theMC1Rlocus. TheMC1R-modified Duroc pigs generated using the allele replacement strategy displayed uniform black coat color across the body. A genotyping assay showed that theMC1R-modified Duroc pigs had a heterozygousED1/eallele at theMC1Rlocus; in addition, the pigs remained in the Duroc genetic background. Our work offers a gene editing method for pig coat color manipulation, which could value the culture of new pig varieties meeting the needs of diversified market.Keywords:coat color;CRISPR;gene editing;homologous recombination;MC1R;pig