THE EXPRESSIONAL CHARACTERIZATION OF MIR-222 IN MANDARIN FISH (SINIPERCA CHUATSI)

The mandarin fish (Siniperca chuatsi Basilewsky) is one of the most commercially important carnivorous fish species in aquaculture. Increasing evidences have suggested that microRNAs (miRNAs) have emerged as key regulators of skeletal muscle growth, but little is known about miRNA expression profiles relate to skeletal muscle growth in teleost. The miR-222 has been reported as the key regulator during muscle differentiation. To investigate the expression pattern of miR-222 in different tissues and developmental stages in Siniperca chuatsi, the expression of miR-222 was detected by RT-qPCR. In the present study, we found that the miR-222 was highly expressed in muscle-related tissues, especially in fast (white) muscle of adult mandarin fish. RT-qPCR analysis revealed that the miR-222 was first detected in two cell stage embryos and highly expressed at the heart beating stage. The differential expression of miR-222 in different tissues and developmental stages indicated that miR-222 might involve in regulating muscle growth and development. We investigated the expression changes of the mature miR-222 abundance following a single satiating meal in mandarin fish juveniles after fasting for a week. MiR-222 expression was sharply up-regulated within 1h after refeeding and might be desired candidate miRNA involved in a fast-response signaling system that regulates fish skeletal muscle growth. This finding would provide a novel insight in the role of miR-222 in teleost development.