Abstract
Members of the genus Biomphalaria represent air-breathing (pulmonate) aquatic gastropod molluscs of great medical importance. The majority of species are obligatory intermediate hosts of the trematode flatworm Schistosoma mansoni, a pathogen responsible for the devastating neglected tropical disease schistosomiasis. Since the spread of the disease is governed by the temperature tolerance of its molluscan host, the envisaged rise in global temperatures will allow for the further expansion of the snail outside the native range into temperate regions. While schistosomiasis is currently predominantly controlled by praziquantel-mediated chemotherapy of infected individuals, novel strategies are needed in the longer term. The availability of the new Biomphalaria glabrata genome importantly now enables the design of next-generation schistosomiasis control strategies focused on the intermediate host. Here, using a variety of diverse approaches, we functionally characterise the critically important molecular process DNA methylation in B. glabrata, which is mediated by a suite of biological participants and is involved in a wide range of metazoan functions. Importantly, we confirm the presence of 5mC within the snail’s genome using global as well as locus-specific methodologies and we further provide the first evidence for a S. mansoni-provoked modulation of the intermediate’s host DNA methylation system