Novel alternative splicing by exon skipping in KIT associated with whole‐body roan in an intercrossed population of Landrace and Korean Native pigs

Abstract

The KIT locus has been suggested to be a strong candidate region linked with whole-body roan in the F(2) population produced by intercrosses between Landrace and Korean Native pigs. In this manuscript, we report the finding of a novel alternative splicing event in the porcine KIT gene that results in the skipping of exon 5 in the I(Rn) allele. KIT mRNAs that lack exon 5 were identified in the large intestine and skin, suggesting that the mechanism responsible for the skipping of exon 5 may be tissue specific. A U(26) repeat in intron 5 showed complete linkage (LOD = 11.8) with the roan phenotype and absolute association with the black phenotype of the Korean Native pig (KNP) population samples, inferring that the repeat pattern may alter the complementary base-pairing-mediated looping-out of introns 4 and 5, which may mediate the exon 5-skipping event. Although the sample size in our study was relatively small, we speculate that the R3 allele containing the U(26) repeat is a causative element for the roan phenotype via alternative control of the exon skipping in our roan pedigree.