Immune characterization and expression analysis of a goose-type lysozyme gene from Pinctada fucata martensii

Abstract

In the present study, a g-type lysozyme was successfully screened and cloned from Pinctada fucata martensii (designated as PmlysG). The cDNA has a length of 973 bp with an open reading frame (ORF) of 769 bp, encoding a protein of 255 amino acids. The PmlysG transcript was detected in multiple tissues by quantitative real-time PCR (qRT-PCR), with the highest expression being in the hepatopancreas. Additionally, the temporal expression of PmlysG mRNA in the hepatopancreas after in vivo stimulation with pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide (LPS), peptidoglycan (PGN) and polyinosinic acid (PolyI:C) was detected by qRT-PCR. Although PmlysG responded to all three stimulation modes, it rapidly responded to PGN stimulation. Meanwhile, the recombinant protein of g-type lysozyme of P.f. martensii (rPmlysG) was used for antibacterial function analysis, and the results showed that rPmlysG has antibacterial function against Vibrio parahaemolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. Overall, these study results suggest that the identified PmlysG participates in the innate immune responses of P.f. martensii against pathogen infection.