Gene cloning, characterization and expression analysis of <scp> <i>MAVS</i> </scp> in Chinese black sleeper ( <scp> <i>Bostrychus sinensis</i> </scp> )

Mitochondrial antiviral signalling protein (MAVS) is a critical adaptor in RIG-I-like receptor-mediated antiviral innate immunity; however, its molecular characteristics and expression profiles in Chinese black sleeper (Bostrychus sinensis) remain poorly understood. In this study, the full-length coding sequence of MAVS from B. sinensis (BsMAVS) was cloned and characterized. BsMAVS encodes 827 amino acid residues and contains a conserved caspase activation and recruitment domain (CARD). Multiple sequence alignment and phylogenetic analyses demonstrated that BsMAVS, particularly its CARD domain, is highly conserved among teleost species. Furthermore, qPCR analysis indicated that BsMAVS is constitutively expressed in various tissues of healthy B. sinensis, with relatively higher expression levels in immune-related tissues, including the spleen and head kidney. BsMAVS expression was dynamically regulated in the spleen, peripheral blood, liver and head kidney following polyinosinic-polycytidylic acid (poly[I:C]) stimulation. These results provide baseline molecular and expression information for MAVS in B. sinensis, contributing to a better understanding of antiviral-related genes in teleost fishes.