Spatiotemporal Expression Characterization of KRTAP6 Family Genes and Its Effect on Wool Traits.

Keratin-related proteins (KAPs) are structural components of wool fibers and are thought to play a key role in regulating the physical and mechanical properties of fibers. Among all KAP genes ( KRTAPs ), KRTAP6 gene family ( KRTAP6-1 , KRTAP6-2 , KRTAP6-3 , KRTAP6-4 , and KRTAP6-5 ) is a very important member with high polymorphism and notable association with some wool traits. In this study, we used real-time fluorescence quantitative PCR (RT-qPCR) and in situ hybridization to investigate spatiotemporal expression of KRTAP6s . The results revealed that KRTAP6 family genes were significantly expressed during anagen compared to other stages ( p < 0.05). And it was found the five genes were expressed predominantly in the dermal papillae, inner and outer root sheaths, and showed a distinct spatiotemporal expression pattern. Also, it was found that KRTAP6-1 and KRTAP6-5 mRNA expression was negatively correlated with wool mean fiber diameter (MFD) and mean staple strength (MSS) ( p < 0.05). In summary, the KRTAP6 family genes share a similar spatiotemporal expression pattern. And KRTAP6-1 and KRTAP6-5 may regulate the MFD and MSS of Gansu Alpine fine-wool sheep wool by changing the expression.