Receptors that recognize conserved pathogen molecules are the first line of cellular innate
immunity defense. Toll-like receptors (TLRs) are the best understood of the innate immune
receptors that detect infections in mammals. Key features of the fish TLRs and the factors
involved in their signaling cascade have high structural similarity to the mammalian TLR
system. However, the fish TLRs also exhibit very distinct features and large diversity which is
likely derived from their diverse evolutionary history and the distinct environments that they …