A Reverse Genetic Analysis of Components of the Toll Signaling Pathway in Caenorhabditis elegans

Molecular cloning and expression of a Toll receptor gene homologue from Zhikong Scallop, Chlamys farreri

“…Phylogenetic analysis based on TIR domains also suggested that CfToll-1 was a close homolog to DmToll and DmToll5. In contrast, the only TLR homolog identified in Caenorhabditis elegans (CeTOL-1) [52] was not clustered with DmToll and DmToll5. Previous studies suggested that CeTOL-1 had no pathogen resistance role [52], while DmToll and DmToll5 were proved to activate the drosomycin promoter in transfected cells [46].…”

Pathogen recognition by innate receptors

“…5 The nematode Caenorhabditis elegans also has a TLR. 6 To date, TLRs have been cloned not only from mammals but also from other vertebrates, such as jawless fi sh, 7 and various invertebrates, such as the sea squirt, 8 sea urchin, 9 horseshoe crab, 10 and shrimps. 11 The subfamilies of TLR1, TLR2, and TLR6 recognize lipid and carbohydrate compounds from Gram-positive bacterial cell walls.…”

Immunity in Caenorhabditis elegans

“…Although homologues of certain components of the Toll pathway are present in C. elegans, they do not appear to be directly involved in resistance against fungal or bacterial infection, at least not against the limited number of pathogens that have been tested [20 ,21]. Results suggest, however, that the worm Toll homologue could be part of a mechanism that allows worms to discriminate between bacteria, and thereby avoid potential pathogens [21].…”