Effects and regulatory pathway of proopinmelanocortin on feeding habit domestication in mandarin fish

•Pomc played an important role in feeding habits domestication in mandarin fish.•The region with c-fos binding site of pomc gene exhibited positive promoter activity.•The c-fos siRNA treated brain cells displayed suppressed pomc mRNA expression.•c-fos and setd1b were highly expressed in the fish which was difficult to domesticate.•The activation of c-fos gene by histone H3K4me3 was catalyzed by setd1b.