Molecular cloning, expression and characterization analysis of p53, Bax, Caspase-3 and AIF genes from Portunus pelagicus under Vibrio parahaemolyticus challenge.

Portunus pelagicus is an important marine economic species, widely distributed in coastal areas such as the Indian Ocean and the western Pacific Ocean. As a pathogenic bacterium, Vibrio parahaemolyticus poses a potential threat to marine life living in coastal areas. As key regulatory factors in the process of apoptosis, p53, Bax, Caspase-3 and AIF genes play an important role in removing infected cells and inhibiting the spread of pathogens. This study evaluated the acute toxicity, tissue damage, and induced apoptosis of V. parahaemolyticus infection in P. pelagicus through physiological and molecular responses, and analyzed the expression spectrum of p53, Bax, Caspase-3, and AIF genes. The results showed that the 48 h LD50 of V. parahaemolyticus infection in P. pelagicus was 1.72 × 107 CFU/mL. The toxic effect of this bacterium significantly affected the tissue morphology and apoptosis levels of P. pelagicus hepatopancreas and gill tissues. Through RT-PCR, p53, Bax, Caspase-3, and AIF genes were successfully cloned, with open reading frames (ORFs) of 885, 1509, 1074, and 1323 bp, respectively. Through RT-qPCR, it was found that p53, Bax, Caspase-3, and AIF genes were expressed in the stomach, epidermis, hepatopancreas, gill, heart, intestine, muscle, and eyes tissues. Among these, expression levels in the hepatopancreas and gill tissues were notably higher. Overall, V. parahaemolyticus activates immune responses in P. pelagicus, causing tissue structural damage and elevating apoptosis levels, thereby compromising normal growth and health.