Comparative transcriptome analysis identified genes involved in ovarian development in Takifugu rubripes.

Ovarian development is a complex process involving multiple genes, but the molecular mechanisms underlying this process in Takifugu rubripes remain poorly understood. This study aimed to identify genes associated with ovarian development in T. rubripes and to investigate the regulatory mechanisms of oocyte maturation. Transcriptome data were compared across four different developmental stages (stage II to V) to identify differentially expressed genes (DEGs) and perform GO and KEGG enrichment analysis. The expression patterns of randomly selected genes were then validated by qPCR. The results yielded a total of 1,289,401,820 raw data from all libraries, with 16,929 DEGs identified across all comparison groups. The DEGs were predominantly enriched in ovarian steroidogenesis, estrogen-mediated signaling, and TGF-beta signaling pathways. The qPCR analysis showed that cyp17a1 was identified as being expressed at similar levels in stage II and III. Thereafter, cyp17a1 was observed to undergo a continuous increase in expression from stage III to V. cyp19a1, nanos1, foxl2 and ar were identified as being expressed at similar levels at stage II and III, then increase in expression from stage III to IV and subsequent downregulation from stage IV to V. hsd17b1 was identified as being expressed at similar levels at stage II and IV. This study represents a transcriptomic study of ovarian development in female T. rubripes. Several essential ovarian-related genes and sex-related biological pathways were identified. The results will improve our understanding of the molecular mechanisms underlying ovarian development in this species.