Molecular Characterization and Expression Pattern of a Liver-Expressed Antimicrobial Peptide 2 (LEAP-2) Gene in Yellow Catfish (Pelteobagrus fulvidraco)

Abstract

Liver-expressed antimicrobial peptide 2 (LEAP-2) is a member of antimicrobial peptides, which acts as an important component of the host innate immune system and plays a crucial role in host defense against microbial invasion. In this study, a LEAP-2 gene (PfLEAP-2) was amplified from the liver of yellow catfish (Pelteobagrus fulvidraco) by reverse transcription PCR. The length of P LEAP-2 open reading frame was 282 bp, which encode 94 amino acids (aa) including a 28-aa signal peptide, a 21-aa prodomain, and a 45-aa mature peptide. The results of tissue distribution showed that PfLEAP-2 mRNA was mainly expressed in the gill, skin, stomach, and head kidney. The significant up-regulation of PfLEAP-2 in liver after 4 hours of challenge of Edwardsiella tarda suggested, PfLEAP-2 might play an important role in the early immune defense of the yellow catfish against bacterial pathogen