miRNA对虎龙斑补偿生长及非特异性免疫的影响研究

Effect of miRNA on the Growth Compensation and Non-specific Immunity of Hybrid Grouper(Epinephelus fuscoguttatus♀ × E. lanceolatus ■)

为了研究饥饿再投喂过程中虎龙斑肝脏miRNA(miR-27a、miR-214、miR-206和miR-125b)的表达水平与补偿生长,免疫水平之间的关系,本研究选取了120尾虎龙斑随机分为4个试验处理组(S15、S30、R15和R30)和4个对应的对照组(C15、C30、C45和C60).检测虎龙斑肌肉中miRNA表达水平、血清中溶菌酶(LYM)、超氧化物岐化酶(SOD)和丙二醛(MDA)的活性变化.结果表明,在饥饿期时,处理组血清中的SOD活性和MDA含量均高于相应对照组.但随时间的延长,处理组均显著性下降(P <0. 05),处理组肌肉中miR-214和miR-206的相对表达量与相应对照组相比,有先升高后降低的趋势,其中处理组S15中miR-214和miR-206的相对表达量显著高于对应对照组(P <0. 05);在恢复投喂期,处理组R15和R30的增重率(WGR)、特定生长率(SGR)和摄食率(FR)均高于相应对照组,LYM、SOD活性和MDA含量均呈先升高后降低趋势,而且均高于相应对照组水平,尤其是MDA含量显著高于其他对照组水平(P <0. 05).处理组miR-215b、miR-214和miR-206的相对表达量与对应对照组比,也呈先升高后降低的趋势,而R15和R30中miR-27a的相对表达量一直低于对应对照组水平(P <0. 05).上述结果表明,miR-27a的表达可能与虎龙斑的补偿生长有关,而miR-215b、miR-214和miR-206的表达可能与鱼体的免疫调控有关.

In order to study the relationship between the expression levels of miRNA (miR-27a,miR-214,miR-206 and miR-125b) and the compensatory growth and immune levels in the hybrid grouper ( Epinephelus fuscoguttatus♀×E.lanceolatus ) during starvation and refeeding,a total of 120 hybrid grouper were randomly divided into 8 groups according to sampling time and treatment method:4 experimental groups (S15,S30,R15 and R30) and 4 control groups (C15,C30,C45 and C60).The expression levels of miRNAs were measured in the muscle of hybrid grouper,the content of lysozyme (LYM),the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were tested in the serum.The experiment results showed that the activity of SOD and the content of MD were higher than those of the corresponding experimental groups.However,with the extension of time,the activity of LYM and SOD and the content of MDA decreased significantly in the experimental groups ( P <0.05 ),and the relative expression of miR-214 and miR-206 had a declining trend in the muscles of the experimental groups compared to the control groups,the relative expression of miR-214 and miR-206 of S15 were significantly higher than those of the control group ( P <0.05),the activity of SOD and the content of MDA were higher than those of the corresponding control group.During the refeeding,the weight gain rate (WGR),the specific growth rate (SGR) and feeding rate (FR) of R15 and R30 were higher than those of the control groups;Meanwhile the activity of LYM,SOD and the content of MDA of the experimental groups showed a first increasing then decreasing trend;The activity of LYM,the activity of SOD and the content of MDA of R15were higher than those of the corresponding control levels-notably,the content of MDA which was significantly higher than that of the control groups ( P< 0.05).The relative expression of miR-215,miR-214 and miR-206b showed a first increasing then decreasing trend in the experimental groups when compared with the control groups.The relative expression of miR-27a in the R15 and R30 was constantly lower than that in the control groups ( P< 0.05).These results indicated that the expression levels of miR-27a may be related to the compensatory growth of hybrid grouper in starvation,while the expressions of miR-215b,miR-214 and miR-206 may be related to the immune regulation of hybrid grouper.