塔玛亚历山大藻对中国明对虾免疫相关基因表达和抗病力的影响

以一株能产生麻痹性贝毒（ParalyticShellfishPoison，PSP）的赤潮甲藻塔玛亚历山大藻（Alexandriumtamarense，ATHK株）为研究对象，研究了其对中国明对虾（Fenneropenaeuschinensis）免疫相关基因（TLR和Relish基因）表达和抗病力的影响。结果表明：200cells·mL^-1塔玛亚历山大藻胁迫72~144h，中国明对虾的肝胰腺、鳃和血淋巴的TLR和Relish基因表达或被显著抑制（P〈0．05），或恢复至海水对照组的水平（P〉0．05）；而1000cells·mL。藻中对虾鳃组织和血淋巴的上述基因表达在48～144h被显著抑制（P〈0．05），肝胰腺的表达在72-144h被显著抑制（P〈0．05）。塔玛亚历山大藻胁迫下投喂感染WSSV的病虾后，加藻的感染组和未加藻的感染组的中国明对虾虽然都在第3d时检测到阳性结果，7d内累积死亡率为100％，但同一时间点加藻组的累积死亡率高于未加藻组。塔玛亚历山大藻胁迫6d后的中国明对虾，经鳗弧菌（Vibrioanguillarum）人工急性感染后，两个加藻组在同一取样时间点的累积死亡率高于未加藻的海水对照组，且随着藻浓度升高而有升高的趋势。研究表明塔玛亚历山大藻可影响中国明对虾TLR和Relish基因表达，从而影响机体韵抗病力。t

Influences of Toxic Dinoflagellate Alexandrium tamarense on Relative Expression of Immune Related Genes and Disease Resistance in Fenneropenaeus chinensis

Dinoflagellate A lexandrium tamarense （ ATHK ）, a producer of paralytic shellfish poison, is often found in Fenneropenaeus chi- nensis ponds. Here we studied the influence of A. tamarense on relative expressions of immune related genes（TLR gene and Relish gene） and disease resistance in the Chinese shrimp F. chinensis. Individuals of F. chinensis were exposed to 200 cells ·mL^-1 and 1000 cells ·mL^-1 A. tamarense, and their TLR gene and Relish gene expressions were then determined at 3, 6, 12, 24, 48, 72, 96 h and 144 h. Under expo- sure to 200 cells·mL^-1 A. tamarertse, the relative expressions of TLR gene and Relish gene were not consistently inhibited in the hepatopan- creas, gill and hemolymph of the shrimp between 72 h and 144 h. However, such expressions were significantly inhibited under exposure to 1000 cells ·mL^-1 A. tarrmrense in the gill and hemolymph within 48-144 h and in the hepatopancreas between 72 h and 144 h. After the in- dividuals of F. chinensis pre-exposed to A. tamarense （200 cells·mL^-1 and 1000 cells·mL^-1） were artificially infected with WSSV, a positive infection by the WSSV was detected after 3 days. The cumulative mortality of F. chinensis was 100% after 7 days for exposure to both A. tamarense and seawater control, but was higher in the A. tamarense group than in the seawater control group at the same sampling time. In addition, when shrimps were exposed to A. tamarense for 6 days, followed by infection with Vibrio anguillarum, their cumulative mortality at the same sampling time was still higher in the A. tamarense group than that in the seawater control. Therefore,it is suggested that A. tamarense affect the relative expressions of TLR and Relish genes and disease resistance in F. chinensis.