Transcriptome analysis of putative key signaling pathways and genes in the nidamental gland tissue associated with reproductive regulation of golden cuttlefish (Sepia esculenta Hoyle)

Abstract

Studies have found that the substances secreted by the nidamental gland are involved in the formation of the third-level membrane of the fertilized egg and may be closely related to the reproductive activities of cephalopods. However, there is currently a lack in molecular evidence of the involvement of the nidamental gland in reproductive regulation. In this study, RNA sequencing was performed of the nidamental gland tissue of female golden cuttlefish, Sepia esculenta (Hoyle) collected at three key physiological stages: growth stage (NG), spawning stage (NS), and post-reproductive death stage (NA). In total, 65.59 Gb of clean data (Q20 > 96%) were obtained. Pairwise comparative analyses of NG vs. NS and NG vs. NA identified 1889 and 6574 differentially expressed genes (DEGs), respectively, while only 95 DEGs were identified by comparison of NS vs. NA. Venn diagrams of the three developmental groups identified 7021 DEGs. By analyzing genes classified as “reproduction” and “reproductive process” in the GO functional classification, the 14–3–3 protein epsilon-like gene and zinc finger RNA-binding protein-like gene were identified. The significantly enriched pathways included the cell cycle, protein digestion and absorption, p53 signaling pathway, mTOR signaling pathway, PI3K-Akt signaling pathway, and lysosomes. Furthermore, the “mucin type O-glycan biosynthesis” and “steroid biosynthesis” pathways related to reproduction were significantly enriched during spawning and senescent stages. This study clarified the regulation of transcript expression in the nidamental gland of S. esculenta at different physiological stages, thereby providing a valuable genomic resource to reveal the role of the nidamental gland in reproduction.