地衣芽孢杆菌对凡纳滨对虾Toll和HSP70基因表达的影响

Effect of Baclicus lincheniformis on mRNA expression of Toll and HSP70 genes in Litopenaeus vannamei

目的分析地衣芽孢杆菌对凡纳滨对虾Toll和HSP70基因表达的影响。方法根据芽孢杆菌的使用量设置测试1组(LDG,用菌量2.0×103CFU/mL),测试2组(HDG,用菌量1.0×104CFU/mL)及未使用芽孢杆菌的对照组(CG),每7 d施菌1次,实验持续24 d。每6 d取样对虾肌肉和肝胰腺检测Toll基因和HSP70基因的mRNA相对表达量。结果对虾肝胰腺Toll基因mRNA表达量在LDG组和HDG组分别较CG组提高了410.05%和78.31%,但在肌肉中CG组的表达量则分别较LDG组和HDG组提高了31.81%和8.43%。可见,芽孢杆菌在一定程度上可提高Toll基因mRNA在对虾肝胰腺的表达,但对其在肌肉中的表达则呈一定的限制作用。在肝胰腺HSP70基因的mRNA表达量,HDG组显著高于CG组和LDG组(P<0.05),CG组和LDG组的差异无统计学意义(P>0.05);在肌肉中LDG组和HDG组的HSP70基因mRNA表达分别较CG组提高了26.07%和26.46%,但实验组的组间差异无统计学意义(P>0.05)。结论在水体中施用芽孢杆菌104CFU/mL和2.0×103CFU/mL可分别提高对虾肝胰腺和肌肉HSP70基因的mRNA表达量。

Objective To study the effect of Baclicus on mRNA expression of Toll and HSIrlO in Litopenaeus vannamei. Methods Three groups were established based on the concentrations of Baclicus used, including test group 1 （high dosage group, HDG） , test group 2 （ low dosage group, LDG） and control group （CG） ; the concentrations of Baclicas were 1.0 × 10^5 CFU/mL, 2.0 × 103 CFU/mL and 0 CFU/mL, respectively. Relative expression of Toll β-actin and HSP70 mRNA in hepatapancreas and muscle of L. vannamei were tested every 6 days, until the 24th day when this study ended. Results The relative Toll β-actin mRNA expressions in hepatapancreas in LDG and HDG were significantly higher than that of CG （ P 〈 0.01 ）, increased by 410.05% and 78.31% respectively compared with CG, while those in muscle in were reduced by 31.81% and 8.43% , respectively. It indicated that B. lincheniformis could improve Toll β-actin mRNA expression in hepatapancreas but inhibit its expresion in muscle of L. vannamei. The relative HSP70 mRNA expression in hep- atapaucreas in HDG was significantly higher than those in LDG and CG （P 〈 0.05 ）. Its expressions in muscle in LDG and HDG were in- creased by 26.07% and 26.46%, respectively, but there was no significant difference between LDG and HDG （ P 〉 0.05）. It intimated that the Baclicus concentration used was important to the mRNA expression of HSP70 in L. vannamei. Conclusion Application of B. lincheniformis in aquaculture water can improve the expressions of Toll β-actin and HStrlO mRNAs in L. vannamei, which would enhance the disease resistance of cultured shrimps.