Genome-Wide Analysis Indicates a Complete Prostaglandin Pathway from Synthesis to Inactivation in Pacific White Shrimp, .

Prostaglandins (PGs) play many essential roles in the development, immunity, metabolism, and reproduction of animals. In vertebrates, arachidonic acid (ARA) is generally converted to prostaglandin G (PGG) and H (PGH) by cyclooxygenase (COX); then, various biologically active PGs are produced through different downstream prostaglandin synthases (PGSs), while PGs are inactivated by 15-hydroxyprostaglandin dehydrogenase (PGDH). However, there is very limited knowledge of the PG biochemical pathways in invertebrates, particularly for crustaceans. In this study, nine genes involved in the prostaglandin pathway, including a , seven s (, , , , , and ), and a were identified based on the Pacific white shrimp () genome, indicating a more complete PG pathway from synthesis to inactivation in crustaceans than in insects and mollusks. The homologous genes are conserved in amino acid sequences and structural domains, similar to those of related species. The expression patterns of these genes were further analyzed in a variety of tissues and developmental processes by RNA sequencing and quantitative real-time PCR. The mRNA expression of was relatively stable in various tissues, while other genes were specifically expressed in distant tissues. During embryo development to post-larvae, , , , and expressions increased significantly, and increasing trends were also observed on , , and at the post-molting stage. During the ovarian maturation, decreasing trends were found on , , and in the hepatopancreas, but all gene expressions remained relatively stable in ovaries. In conclusion, this study provides basic knowledge for the synthesis and inactivation pathway of PG in crustaceans, which may contribute to the understanding of their regulatory mechanism in ontogenetic development and reproduction.