Comparative Transcriptomic Analysis of Gonad Development and Renewal of Ovoviviparous Black Rockfish (Sebastes Schlegelii)

Abstract Background: Black rockfish (Sebastes schlegelii) has an ovoviviparous reproductive pattern and long-term sperm storage, which resulting in asynchronous gonadal development between the sexes. While the comprehensive understanding of gonad development of black rockfish has not been well studied. Here, we study the gonad development and germ cell renewal by histology and RNA-seq.Results: In this study, RNA-seq was performed on both testis and ovary to characterize key pathways and genes during development and gamete maturation in black rockfish. Different expression genes (DEGs) were identified and annotated in 4 comparisons (F_III vs F_IV, F_IV vs F_V, M_III vs M_IV and M_IV vs M_V). Based on enriched analysis of DEGs in testis, 11 and 14 significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were mapped in M_III vs M_IV group and M_IV vs M_V group, respectively. And DEGs in ovary development periods were also classified into 10 biological function group. The results of the q-PCR expression pattern of the selected genes was significantly correlated with the RNA-Seq results, implying the reliability and accuracy of the RNA-Seq analysis.Conclusion: The categories intercellular interaction and cytoskeleton, molecule amplification and repairment in cell cycle were revealed to be crucial in testis development and spermatogenesis along with a series of metabolite biosynthesis. Our results provided a comprehensive insight into the black rockfish gonad development for further study of reproductive physiology and molecular biology in ovoviviparity.