Transcriptomic of lsm14bl overexpressed Testicular Cells of Cynoglossus semilaevis

The protein_LSM14_homolog_B, an important member of the LSM14 protein family, plays the key function in oocyte development and maturation. However, the role of lsm14b in sex determination in fish remains poorly understood. This study aimed to investigate the expression patterns, cellular localization, and potential regulatory roles of lsm14b during ovarian development and sex differentiation in Cynoglossus semilaevis. Accordingly, C. semilaevis lsm14b subfamily was identified, followed by phylogenetic analysis, spatiotemporal expression profiling, ovarian in situ hybridization, and overexpression-based transcriptome analysis. The results showed that Cs_lsm14b and Cs_lsm14bl both contain the conserved LSM14 and FDF domains, which show a high homology to fish and mammalian LSM14B in the phylogenetic analysis. Besides, Cs_lsm14b genes wer significantly expressed and enriched in ovarian tissues across multiple developmental stages, exhibiting a clear female-biased expression pattern. In situ hybridization further indicated that Cs_lsm14bl was mainly localized in oocytes, with the strongest signals at early stages. In addition, Cs_lsm14bl overexpression in testicular cells significantly affected pathways related to DNA replication, cell cycle, homologous recombination, p53 signaling, oocyte meiosis, and progesterone-mediated oocyte maturation. Overall, the findings of this study may demonstrate that Cs_lsm14b subfamily play an important role in ovarian development in C. semilaevis, providing a molecular basis for understanding the evolution and function of the LSM14 family and the mechanisms of sex determination and oocyte development in fish.