Illumina-sequencing based transcriptome study of coat color phenotypes in domestic goats

This study performed a comprehensive expression profiling of genes expressed in the skin of goats with three different coat colors by Illumina Sequencing. A total of 91 significantly expressed genes were detected when comparing gray skin to white skin library and these included 74 up-regulated and 17 down-regulated genes in gray skin. There were 67 differentially expressed genes between brown skin and white skin libraries, 23 of which were up-regulated and 44 were down-regulated in brown skin. When we compared brown and gray libraries, 154 differentially expressed genes were found, of which 33 showed higher expression and 121 showed lower expression in brown skin. To our surprise, MC1R, MITF, TYR and KIT showed no significant difference in expression between the goats with three skin colors, whereas ASIP was detected in white skin but not in dark skins. In this study, PMEL, TRPM1, TYRP1 and DCT were significantly up-regulated in brown goat skin compare with gray and white skins. PMEL showed higher expression in gray goat skin compared with white goat skin, whereas there were no significant differences in the expression of TYRP1, TRPM1 and DCT between gray and white skin samples. In addition, ELOVL3 showed higher expression in gray goat skin than in brown and white skins, whereas there was no significant differences in the expression of ELOVL3 between brown and white skin samples. These results expand our understanding of the complex molecular mechanisms of skin physiology and melanogenesis in goat and provide a foundation for future studies.