Genes linked to schistosome resistance identified in a genome-wide association study of African snail vectors

TL;DR

Researchers identified genes in African snails that help them resist a parasite causing schistosomiasis, a tropical disease.

Contribution

The study discovered novel genomic regions in African snails linked to resistance against Schistosoma mansoni, distinct from those in neotropical snails.

Findings

Two genomic regions, SudRes1 and SudRes2, are associated with snail resistance to Schistosoma mansoni.

Resistant and susceptible snail haplotypes show coding differences, including presence/absence of entire genes.

Snail ancestry is strongly correlated with parasite compatibility, suggesting genetic influence on resistance.

Abstract

Schistosomiasis, a neglected tropical disease, is transmitted by freshwater snails. Interruption of transmission will require novel vector-focused interventions. We performed a genome-wide association study of African snails, Biomphalaria sudanica, exposed to Schistosoma mansoni in an endemic area of high transmission in Kenya. Two snail genomic regions, SudRes1 and SudRes2, were significantly associated with snail resistance to schistosomes. SudRes1 includes receptor-like protein tyrosine phosphatases while SudRes2 includes a class of leucine-rich repeat-containing G-protein coupled receptors, both comprising diverse extracellular binding domains suggestive of host-pathogen interaction. Resistant and susceptible haplotypes show numerous coding differences including presence/absence of entire genes. No loci previously tied to schistosome resistance in a neotropical snail species showed any association with compatibility suggesting that loci involved in the resistance of African vectors are distinct. Snail ancestry was also strongly correlated with parasite compatibility. These results will inform future efforts to predict and manipulate immunity of a major schistosome vector.

A genome wide association study of an African vector of schistosomiasis revealed two genomic regions associated with resistance to Schistosoma mansoni. These findings will inform novel control strategies to interrupt transmission to humans.

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