SLC45A2 and GPNMB promote the deposition of melanin in chicken melanocytes. (A) Marker gene identification in chicken primary melanocytes (scale 50 μm). (B,C) The mRNA expression of SLC45A2 and GPNMB after 48 h of transfection of the SLC45A2 overexpression vector pcDNA3.1-SLC45A2-EGFP and the GPNMB overexpression vector pcDNA3.1-GPNMB-EGFP in melanocytes. (D,E) Effects of SLC45A2 and GPNMB overexpression on the expression of genes related to pigmentation melanocytes. (F,G) Effects of SLC45A2 and GPNMB overexpression on MITF protein levels. (H,I) Effect of SLC45A2 and GPNMB overexpression on the tyrosinase content of melanocytes. (J,K) Effect of SLC45A2 and GPNMB overexpression on the melanin content of melanocytes. * p < 0.05; ** p < 0.01.