1. Key Laboratory for Feed Biotechnology of the Ministry of Agriculture; Feed Research Institute, Chinese Academy of Agricultural Sciences; Beijing 100081 People's Republic of China
2. Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology; Pearl River Fisheries Research Institute; Guangdong Province, Guangzhou 510380 People's Republic of China
3. Department of Biological Sciences; Auburn University; Auburn AL 36849 USA