Molecular Genetic Characteristics of the Hoxc13 Gene and Association Analysis of Wool Traits.

Homobox C13 (Hoxc13) is an important transcription factor in hair follicle cycle development, and its deletion had been found in a variety of animals leading to abnormal hair growth and disruption of the hair follicle system. In this study, we used immunofluorescence, immunohistochemistry, real-time fluorescence quantitative PCR (RT-qPCR), and Kompetitive Allele-Specific PCR (KASP) genotyping to investigate molecular genetic characteristics of the Hoxc13 gene in Gansu alpine fine-wool sheep. The results revealed that Hoxc13 was significantly expressed during both the anagen and catagen phases ( p < 0.05). It was found to be highly expressed predominantly in the dermal papillae and the inner and outer root sheaths, showing a distinct spatiotemporal expression pattern. Two single nucleotide polymorphisms (SNPs) in the exon 1 of Hoxc13, both the individual locus genotypes and the combined haplotypes were found to be correlated with wool length ( p < 0.05). It was determined the mutations led to changes in mRNA expression, in which higher expression of this gene was related with longer wool length. In summary, this unique spatiotemporal expression pattern of the Hoxc13 gene may regulate the wool length of Gansu alpine fine-wool sheep, which can be used as a molecular genetic marker for wool traits and thus improve the breed.