TISSUE EXPRESSION DIFFERENCES OF MELANOCORTIN 1 RECEPTOR (MC1R) IN DIFFERENT TANK BACKGROUNDS AND PROMOTER REGULATORY ELEMENTS ANALYSIS OF CHINESE PERCH (SINIPERCA CHUATSI)

In order to explore the tissue expression difference and transcriptional regulation mechanism of mc1r gene in Chinese perch (Siniperca siniperca) under different culture backgrounds, the dark and light surface Chinese perch under black and white tank backgrounds were used as the research objects, and the tissue expression differences of mc1r gene were determined by Quantitative real-time PCR (qRT-PCR). In addition, the researchers amplified different lengths of the promoter deletion fragments at the 5′ flanking region of the mc1r gene by PCR, and cloned them into pGL3-Basic plasmids, then transfected the recombinant plasmids into human embryonic kidney (HEK293T) cells and measured the relative activity of dual luciferase to predict its potential transcription factors. The results showed that the Chinese perch cultured in the black background had a deeper body color similar to that of the wild Chinese perch. The expression of mc1r gene in dark-colored Chinese perch was the highest in the dorsal and ventral skin, while that of light-colored Chinese perch was the highest in brain. The double luciferase activity detection revealed that the promoter activities of the constructed five deleted fragments were significantly different, with the −159∽+292 bp promoter fragment had the highest activity, which was speculated to be the core region of the mc1r promoter. The online software predicted the existence of transcription factors such as MITF and SP1 in the core promoter region. In this study, the promoter region of the Chinese perch mc1r gene was cloned for the first time and the transcriptional activity was analyzed, and then the potential transcription factors were predicted. This study provides a theoretical basis for further research on the expression and regulation of the molecular mechanism of the mc1r gene in fish.