Transcriptome reveals genes involving in black skin color formation of ducks

Abstract

Background Skin color is colorful for birds, which has been reported to be associated with multi-biological functions, such as crypsis, camouflage, social signaling and mate choice, but little is known about its underlying molecular mechanism. Objective Studies on the major genes affecting the black skin color of ducks. Methods For this purpose, Silver ammonia staining and RNA-seq analysis were carried out to identify the differences in tissue morphology and gene expressions between black and yellow skin ducks. Results The silver ammonia dyes slice results showed that in the development of black duck, the content of melanin in black skin gradually increased and then decreased, and the content of melanin in yellow and black skin was significantly different. Through transcriptome, a total of 102 and 84 differentially expressed genes (DEGs) were identified in beak skin and web skin, respectively. These DEGs were enriched in melanin biosynthesis and play a critical role in melanogenesis pathway. Co-expression analysis showed that EDNRB2 was the only gene associated with black skin color in DEGs, which was also consistent with qRT-PCR. Conclusions The melanin synthesis pathway dominated by EDNRB2 up-regulated the amount of melanin synthesis, leading to the formation of black skin in ducks.