Changes in serum index and hsp70 gene expression in Siberian sturgeon Acipenser baerii challenged with Aeromonas veronii
TIAN Zhao-hui, XU Shao-gang, ZHU Hua, HU Hong-xia, WANG Wei, DONG Ying
Beijing Key Laboratory of Fishery Biotechnology, National Engineering Research Center for Freshwaters(Beijing), Beijing Fisheries Research Institute, Beijing 100068, China
Abstract: Siberian sturgeon Acipenser baerii with body weight of (260.2±37.8)g were injected with Aeromonas veronii in dorsal muscles and serum indices including activities of lysozyme (LZM), superoxide dismutase (SOD) and contents of cortisol, and malondialdehyde (MDA) and hsp70 gene expression were studied in liver, spleen, intestine and gill by quantitative PCR to evaluate the immune physiological response of Siberian sturgeon infected by the bacteria. The initial mortality was observed in the fish 40 h after muscular injection, no death was found 62 h after muscular injection, with cumulative mortality of 46.7%. The minimal serum cortisol content was observed in the fish in the control group in 40 h exposure and in the treatment groups in 53 h exposure without compared with the samples collected in the no death period (P>0.05) and significant difference from the diseased fish in the treatment groups (P<0.05). The minimal SOD activity was found in the fish in the treatment groups in 62 h exposure and significant difference from the fish in the control group in 40 h and 93 h exposure, in the treatment groups in 53 h, 62 h and 93 h exposure and in the normal fish in the treatment groups in 53 h exposure (P<0.05). There was significant difference in MDA level in the treatment in 93 h exposure from those in the treatment groups in 40 h, 44 h, 53 h, and 62 exposure (P<0.05), without significant difference among the other groups (P>0.05). The lysozyme activity was found to be increased in the treatment groups in 44 h exposure, significantly higher in 62 h exposure than those in the treatment groups in 40 h, 93 h, and 168 h exposure and in the control group in 40 h, 93 h, and 168 h exposure (P<0.05). The findings indicate that the expression of hsp70 gene in tissues is more responsive than serum cortisol level and lysozyme activity which act as the reference indices of the immune status at high values，and that the higher hsp70 gene expression was first found in gills.
2015, Vol. 30 
