Hebei Key Laboratory of Preventive Veterinary Medicine;
Hebei Normal University of Science and Technology;
Qinhuangdao 066004;
China;
Key Laboratory of Sustainable Development of Marine Fisheries;
Ministry of Agriculture;
Yellow Sea Fisheries Research Institute;
Chinese Academy of Fishery Sciences;
Qingdao 266071;
China;
gene cloning; expression; reactive oxygen species; metalloprotease; head kidney cells;