Expression Localization of the KRT32 Gene and Its Association of Genetic Variation with Wool Traits

Abstract

Changes in keratin gene expression and spatiotemporal regulation determine the compositional content and cellular localization of wool keratin, thereby affecting wool traits. Therefore, keratin gene family member 32 (KRT32) was selected for a study using RT-qPCR, immunofluorescence, and penta-primer amplification refractory mutation system (PARMS) techniques. The results showed that KRT32 mRNA was highly expressed in the skin and localized to the inner root sheath (IRS), outer root sheath (ORS) and dermal papilla (DP). Sequencing results identified eight SNPs in KRT32, and association analyses revealed that the variations were significantly associated with multiple traits in wool (p < 0.05), including MFD, CF and MFC. The constructed haplotype combination H2H3 has higher CF and smaller MFD than other haplotype combination (p < 0.05). In conclusion, KRT32 can be used as a candidate gene for molecular genetic improvement of wool in Gansu Alpine Fine-wool sheep.