Integrated transcriptomic and lipidomic analysis reveals that arachidonic acid mediates the allograft-induced stress response in Pinctada fucata martensii

This study investigated the protective effect of arachidonic acid (ARA) against the allograft-induced stress response in Pinctada fucata martensii by characterizing pearl production traits and changes in genes and lipids during postoperative care. Survival and pearl production traits were higher in the ARA treatment group (ARAG) than in the control group (CG). There were 1536 differentially expressed genes (DEGs) in CG-1d vs ARAG-1d and 833 DEGs in CG-3d vs ARAG-3d. DEGs in CG-1d vs ARAG-1d were mainly enriched in "NOD-like receiver signaling pathway," "Glycerolipid metabolism," and "Sphingolipid metabolism." DEGs in CG-3d vs ARAG-3d were mainly enriched in "Apoptosis" and "ARA metabolism." Lipidomics analysis revealed 36 types of lipids. The PC, LPE (22:5), and LPE (18:0) content at 3 d after implantation was lower in the ARAG than in the CG. The PS (37,1) content was significantly higher at 3 d after implantation and the content of ceramides was significantly lower at 1 and 3 d after implantation in the ARAG than in the CG. The results indicated that ARA may alter the composition of lipids, modify the unsaturation of lipids, and regulate apoptosis, immunity, and lipid metabolism in pearl oysters, which enhances pearl production traits. These findings provide theoretical and practical basis for further alleviating the inflammatory response of pearl oysters after implantation.