Expression profiles of penaeidin from Fenneropenaeus chinensis in response to WSSV and vibrio infection by real-time PCR

Penaeidin from Chinese shrimp (Fenneropenaeus chinensis) has proved to be one of the most important antimicrobial peptides in the bodies of animals. The relative quantitative real-time PCR method is developed to study through time, the mRNA expression profile of penaeidin in the muscle and haemoeyte tissue of Chinese shrimp infected with vibrio (Vibrio anguillarum) and WSSV (white spot syndrome virus). Research results showed that the same pathogens infection experiments produced similar gene expression profile in different tissues while different expression profiles appeared in the same tissues infected by different exterior pathogens. In vibrio infection experiments, a “U” like expression profile resulted. Expression levels of ponaeidin increased and surpassed the non-stimulated level, indicating that penaeidin from Chinese shrimp has noticeable antimierobial activities. In WSSV infection experiments, the expression profile appeared as an inverse ““““U““““ with the expression ofpenaeidin gradually decreasing to below baseline level after 24 h.The expression of antimierobial peptides gene in mRNA level in response to virus infection in shrimp showed that international mechanisms ofvirns to haemoeytes and microbial to haemoeytes are completely different. Decline of ponaeidins expression levels may be due to haemoeytes being destroyed by WSSV or that the virus can inhibit the expression ofponaeidins by yet undiscovered modes. The expression profiles of penaeidin in response to exterior pathogen and the difference of expression profiles between vibrio and WSSV infection provided some clues to further understanding the complex innate immune mechanism in shrimp.