Divergent Evolutional Mode and Purifying Selection of theKITGene in European and Asian Domestic Pig Breeds

Abstract

The recent geographic expansion of wild boars and the even more recent development of numerous domestic pigs have spurred exploration on pig domestic origins. The porcine KIT gene has been showed to affect pleiotropic effects, blood parameters, and coat colour phenotypes, especially the white colour phenotype formation in European commercial breeds. Here, we described the use of SNPs to identify different selection patterns on the porcine KIT gene and the phylogenetic relationships of the inferred haplotypes. The phylogenetic tree revealed four clades in European and Asian wild and domestic pigs: two major clades with European and Asian origins and one minor clade with Iberian origins as well as the other minor clade in Asia, consistent with the major introgression of domestic Asian pigs in Europe around 18th -19th century. The domestication history of pigs, which occurred in the domestication centers (Europe and Asia), has also been demonstrated by mtDNA analysis. Furthermore, both Asian and European domestic pigs evolved under purifying selection. This study indicated that domestic pigs in Europe and Asia have different lineage origins but the porcine KIT gene was undergoing a purifying selection during their evolutional histories.

Advancements in DNA analysis for distinguishing wild boar and domestic pig: a mini-review on research developments for food authentication studies

“…Genes for coat color association targeted for exploration by researchers. Pigmentation in mammals is determined by the amount of melanin, eumelanin (black/brown), and phaeomelanin (red/yellow), which is controlled by agouti and extension loci [45]. Melanocortin 1 Receptor (MC1R) gene has already been investigated and is a favorable gene for distinguishing pig and wild boar [37,10,39].…”

Identification of a novel c-KIT mutation inducing piebaldism and hearing loss in pigs by ENU mutagenesis

“…To date, six c-KIT alleles have been reported in pigs: i , the recessive allele in wild boar;I Be , the dominant allele for the belt phenotype in Hampshire pigs; I P , the half dominant allele for the patch phenotype in Pietrain; I (I 1 , I 2 , orI 3 ), the completely dominant allele for white color in Landrace and large white pigs. The polymorphisms in the c-KIT sequence could discriminate the European from the Asian groups, the two main clusters produced during the domestication history (Niu, Shi, Xie, Liu, & Zhong, 2018). On the other hand, pigs exhibit more similar audiological characteristics to humans than rodents, including the cochlear structure, the range of audible frequency, and sensitivity to sound (Chen et al, 2016;Guo et al, 2015;Hai, Guo, et al, 2017), making it more advantageous in the research and treatment of hearing loss.…”