Effect of Succinylation Modification on Nucleus-implantation Immune Response of Pinctada fucata martensii
[Objective]To study the effect of protein succinylation modification on nucleus-implantation immune response of Pinctada fucata martensii and provide a theoretical basis for elucidation of the molecular regulatory mechanism of nucleus-inserting reaction of pearl oyster.[Method]We simulated increasing the level of succinylation modification by injecting sodium succinate into P.f.martensii,and examined the degree of succinylation of total protein in gill tissues,the expression of immune-related genes,the enzyme activities of antioxidant-related enzymes,as well as the survival and retention rate of pearly shells after nucleus implantation in P.f.martensii.[Result and Conclusion]After injection of sodium succinate,it was found that the level of succinylation in gill tissue increased significantly at 12 h and 72 h.The temporal expression of immune-associated factors was detected using qRT-PCR,and the results showed that the expression of immune-related factors SOD and Caspase2 were significantly up-regulated at 6 h,NFκB and IRAK1 were significantly up-regulated at 48 h,and TRAF3 and IκK mRNA were significantly up-regulated at 96 h(P<0.05),suggesting that cellular immunity of the recipient oysters was enhanced by the increased level of succinylation modification.The enzymatic activity of antioxidant-related enzyme activities SOD,POD and GSH were significantly up-regulated at 96 h(P<0.05),indicating enhanced humoral immunity in the recipient oysters.Compared to the control group(PBS + implantation)and implantation group,the experimental group(sodium succinate+ implantation)'s survival rate was significantly increased at 7 d and 45 d,and the experimental group's retention rate significantly improveed at 60 d(P<0.05).Succinylation modification is involved in the immune response to implantation in P.f.martensii,and injection of sodium succinate improves immune viability of recipient oysters and helps them to survive the difficult post-implantation period.