饲料中添加益生菌对凡纳滨对虾(Litopenaeus vannamei)非特异免疫基因表达量和抗病力的影响

EFFECTS OF ADDING PROBIOTICS IN THE FEED ON NON-SPECIFIC IMMUNE GENE EXPRESSION AND DISEASE RESISTANCE OF LITOPENAEUS VANNAMEI

采用实时荧光定量PCR方法,进行肠道复合益生菌对凡纳滨对虾相关免疫基因表达量的研究。通过感染实验,分析饲料中添加益生菌对凡纳滨对虾病毒感染能力的影响。结果表明,Real-time PCR揭示在投喂期间饲料中添加芽孢杆菌/溶藻弧菌组的对虾血淋巴细胞中的proPO、SOD和LZM的相对表达量均显著高于对照组(P<0.05);感染WSSV后,对芽孢杆菌/溶藻弧菌组凡纳滨对虾血淋巴7个采样时间点的proPO、SOD、LZM的表达进行Real-time PCR分析,检测表明WSSV刺激24h后,对虾血淋巴中的proPO、SOD和LZM的表达呈现显著性上调,且分别在48h、96h、96h达到最大值。累积死亡率结果证实饲料中添加益生菌均可提高其对虾抗WSSV感染的能力,尤其以坚强芽孢杆菌活菌与溶藻弧菌活菌配合使用效果更佳。

This study was conducted to investigate the effects of Bacillus firmus and Vibrio alginolyticus on relative expression of non-specific immune related genes and antiviral ability ofLitopenaeus vannamei. The relative expressions of non-specific immune related genes encoding prophenoloxidase （proPO）, superoxide dismutase （SOD）, lysozyme （LZM） were analyzed by quantitative real-time reverse transcription PCR （RT-PCR）. The results show that the relative expressions of proPO, SOD, and LZM were obviously up-regulated in hemolymph of shrimp fed diets supplemented with the probiotics compared to the control during the immunization. In hemolymph, the relative expression of proPO, SOD, and LZM were significantly up-regulated 24h post WSSV challenge, and increased to the maximum levels at 48h, 96h, and 96h, respec- tively. The cumulative mortality results confirm that the diet containing probiotics can improve the ability of the shrimp anti-WSSV infection. Results suggest that B. firmus and E alginolyticus are potential candidates for use as probiotics.