The effects of sodium alginate on non-specific immune responses of grouper Epinephelus fuscoguttatus and its resistance to pathogen

• Main Authors: Rung Ting Tsai, 蔡榕庭
• Other Authors: Winton Cheng
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/68882112223254607824

碩士 === 國立屏東科技大學 === 水產養殖系所 === 95 === The purpose of this research is to investigate the non-specific immune reaction of Epinephelus fuscoguttatus after fed diets containing sodium alginate of 0、1000 and 2000 mg/kg, and it’s resistance to Streptococcus sp. and iridovirus infection; moreover, cloning the Myoxvirus Resistance (Mx) is also conducted. These results can futher be used as the database for the examination of parameters and defense system in fish after fed immunostimulants. Immunity measurement shows a significantly higher level of alternative complement activity, respiratory burst and phagocytic activity found in the fish fed sodium alginate containing diets as compared with the fish fed control diet after 6 days. Lysozyme activity and superoxide dimutase activity of fish fed sodium alginate diets for 9 days were significantly higher than that of fish fed control diet. There was a significant increase in the resistance to Streptococcus sp. and iridovirus infection after fed the diets containing sodium alginate, and furthermore, decreased the mortality ratio. Mx cDNA was obtained from the spleen of the E. fuscoguttatus by a reverse-transcription polymerase chain reaction (RT-PCR). The full-length cDNA of Mx consisted of 2163 bp open reading frame encode 626 amino acids (aa), molecular mass of the mature protein was 71.3 kDa with an estimated pI of 5.55. Structure analysis demonstrate: an aminoterminal tripartite GTPase domain, the dynamin family signature, a Centra Interaction Domain (CID) and a carboxy-terminal leucine zipper motif. Grouper were injected intraperitoneally with poly I:C, after induced for 48 hours. There was a significant expression of Mx gene in all tissue of grouper. Keywords: sodium alginate, grouper, non-specific immune, Mx