MicroRNA Dynamics in Gonadal Development and Reproductive Regulation of Striped Murrel, Channa striata (Bloch, 1793)

Abstract

MicroRNAs (miRNAs) are essential regulators of gene expression, influencing a wide range of biological processes, including reproduction and gonadal development. This study investigated the expression patterns of various miRNAs in the gonads of Channa striata across different reproductive stages: prespawning, spawning, and postspawning. The Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) showed significant seasonal variations, with GSI peaking during the spawning season and HSI reaching its highest value in the prespawning period, reflecting reproductive preparation. Our findings highlight the distinct roles of several miRNAs in regulating reproductive processes. The miR-21 was upregulated during spawning in both sexes, indicating its key role in gametogenesis, with persistent expression in males through postspawning, suggesting a role in sperm quality maintenance. MiR-22 also showed upregulation during spawning, supporting its involvement in gamete maturation and steroidogenesis, with reduced expression postspawning. MiR-34a was notably upregulated in male gonads postspawning, highlighting its role in spermatogenic recovery and sperm motility regulation. The miR-133 displayed complex patterns: In females, it was downregulated during spawning and upregulated postspawning, while in males, it was upregulated during spawning but downregulated afterward, highlighting its role in reproductive and metabolic processes. In addition, miR-200 was upregulated during spawning and postspawning in both sexes, underscoring its role in gamete maturation. Lastly, the miR-202-5p was consistent during prespawning and spawning in females but downregulated postspawning, with increased expression during spawning and postspawning in males, indicating its role in sperm maturation. These findings underscore a complex network of miRNAs that regulate gonadal development and reproductive success in C. striata.