Genomic organization, promoter activity of grass carp MDA5 and the association of its polymorphisms with susceptibility/resistance to grass carp reovirus

► Identified MDA5 genomic sequence of 10,906 bp and its organization with seven exons and six introns in grass carp. ► Obtained 5′ flanking region and explored its promoter activity. ► Detected six polymorphisms in grass carp MDA5 genomic sequence. ► Discovered two potential genetic markers for selective breeding of resistant grass carp to grass carp reovirus.