Abstract
Channa striatus is one of the economically important freshwater fish with high demand in Southeast Asia for its nutritional and medicinal values. The unique composition of skin mucus of murrel provides immunity against pathogens; however, they are susceptible to few bacterial pathogens especially Aeromonas hydrophila. Although few immune molecules such as antimicrobial peptides have already been identified from the murrel mucus, there is no report on the complete gene profile of the skin and mucosal immunity. Therefore, in this study we applied transcriptome approach to identify the mRNA sequences of various immune molecules such as antimicrobial peptides, complement factors and adaptive immune molecules from the skin tissue. Transcriptome wide search revealed unique mRNA sequences of 13 antimicrobial peptides, 11 complement components, 2 major histocompatibility complex proteins and its receptor, 6 butyrophilins, 2 leptins and its receptor. Brief bioinformatics analysis of the identified mRNA sequences and their respective putative protein sequences were performed to understand molecular information of those immune components. Further, we analysed the differential expression pattern of selected 13 mRNA sequences representing each immune group using qRT-PCR technique which highlighted the role of those genes during A. hydrophila challenge. Overall, this study revealed the complex immune response of murrel skin and the involvement of various innate and adaptive immune molecules against A. hydrophila infection.