Immune responses and gene expression in hepatopancreas from Macrobrachium rosenbergii challenged by a novel pathogen spiroplasma MR-1008
Jie Du, Huanxi Zhu, Peng Liu, Jing Chen, Yunji Xiu, Wei Yao, Ting Wu, Qian Ren, Qingguo Meng, Wei Gu, Wen Wang*
Abstract:Freshwater prawn Macrobrachium rosenbergii inoculated with 100 ml novel pathogen spiroplasma strain MR-1008 in logarithmic phase (108 spiroplasmas ml1) were examined for alkaline phosphatase (AKP) activity, acid phosphatase (ACP) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, as well as expressions of 7 immune related genes in hepatopancreas after 1e28 d. Hematoxylin-eosin (HE) staining showed obvious pathological features in hepatopancreas connective and epithelial tissue.
Enzyme activity analyze showed that hepatopancreas AKP and ACP activity increased markedly (P < 0.05) when inoculated with spiroplasma MR-1008 after 5 d and 10 d, respectively. SOD enzyme activity changed less obviously and slightly increased at 1 day post-inoculation, but CAT activity decreased significantly after 5 d inoculation. The expression levels of lipopolysaccharide and b-1,3-glucan-binding protein (LGBP), peroxinectin (PE), a2-macroglobulin (a2M), AKP, ACP, CAT, and copper/zinc SOD (Cu, Zn-SOD) genes in the hepatopancreas were examined by Real-Time PCR (qRT-PCR) and the results demonstrated that these immune related genes were induced by challenge with spiroplasma MR-1008. The results suggested that the prawn immune responses could be activated or inhibited by spiroplasma MR-1008, and that the hepatopancreas also plays key roles in innate immunity for defenseagainst the pathogen.