Abstract:Siniperca chuatsi is an economically important freshwater fish in China that prefers to hide near stones or lush grass at the bottom of water bodies. The back and body sides were yellow with dark brown markings, with a white abdomen. Such a unique skin pattern is conducive to hidden predation and avoiding enemies. Research on the formation of different color patterns in mandarin fish skin is mainly based on observing the types and distribution of pigment cells, while research on the corresponding molecular regulation mechanism is relatively scarce. In recent years, omics technology has been applied to the study of fish body color patterns, which can identify candidate pathways and genes related to body color formation. The complex body color pattern of Siniperca chuatsi has ecological significance and economic value. To explore the molecular mechanism of the color pattern formation of Siniperca chuatsi, transcriptome analysis was carried out on the pattern area, non-pattern area, and abdominal skin of the body side of Siniperca chuatsi. The expression changes of tyrosinase family genes in Siniperca chuatsi from the embryo to 30 dph were determined using fluorescence quantitative PCR; this showed that the differentially expressed genes between the three skin regions were mainly enriched in ECM-receptor interaction, tight junction, adhesion, and other pathways, and the MAPK pathway was the core pathway. The expression of tight junction protein 1a (tjp1a) in the non-patterned area was significantly higher than in the patterned and abdominal areas. The expression levels of tyrosinase-related protein 1 (tyrp1), dopachrome tautomerase (dct), and melanocyte-inducing transcription factor a (mitfa) in the patterned areas were significantly higher than those in the non-patterned and abdominal areas. The expression of the agouti signaling protein 1 (asip1) gene in the abdominal region was significantly higher than in the patterned and non-patterned regions. In the early development of Siniperca chuatsi, the expression of the tyrosinase (tyr) and dct genes began to increase significantly at the gastrula stage (P<0.05). The tyrp1 gene began to increase significantly at 1 dph (P<0.05). The expression of the tyr, tyrp1, and dct genes decreased significantly at approximately 7 dph and was maintained at a certain level at 25 dph. In summary, tjp1a, tyr, tyrp1, dct, mitfa, and asip1 help form the body color pattern of Siniperca chuatsi. The expression of tyrp1 lags behind tyr and dct in melanin synthesis during the early development of Siniperca chuatsi. The expression of tyr, tyrp1, and dct tended to be stable after high expression to maintain pattern formation.