CDK1 promotes the proliferation of melanocytes in Rex rabbits

Background The fur color constitutes one of the most important economic characteristics of fur animals and is determined by the content of melanin. A previous study has shown that the cyclin-dependent kinase 1 ( CDK1 ) is a member of the protein kinase family, involved in forming the color of the fur in Rex rabbits. However, its effect on the melanocytes remains unclear. Objective This study aimed to provide evidence for the role of CDK1 in melanogenesis. Methods This study measured the expression of CDK1 in Rex rabbit skins of six coat colors using qRT-PCR. The CDK1- mediated regulation of the pigmentation-related genes and cyclin-dependent kinases were analyzed. The melanin content, proliferation, and apoptosis of the melanocytes were analyzed using the NaOH, CCK8, and Annexin V-FITC methods. Results The CDK1 expression in the skin of the rex rabbits with different coat colors was found to be regular, and the expression level was found to be the highest in the skin of the black rex rabbits ( P < 0.05). The overexpression/knockdown of CDK1 was found to significantly increase/decrease the melanin content in the melanocytes ( P < 0.01). Besides, CDK1 was found to significantly promote the proliferation of the melanocyte and inhibit apoptosis ( P < 0.01). Furthermore, the overexpression of CDK1 was found to significantly affect the expression of the other melanin-related genes like TYR , PMEL , DCT , as well as the mRNA expression of the cyclin-dependent kinases CDK4 , CDK6 , CDK8 , CCNB1 . Conclusions The results indicated that CDK1 can serve as a key gene regulating melanogenesis, melanocyte proliferation, and apoptosis, providing a new theoretical basis for studying the mechanism by which the different colors of the fur evolve in mammals.