RNA interference as a tool for functional genomics in parasitic helminths

Helminths including flatworms, tapeworms, flukes, and roundworms are the causal agents of several Neglected Tropical Diseases (NTDs), affecting the health of humans and animals worldwide and resulting in significant economic losses. Given the importance of helminth infections and the complex life cycle of those parasites, often including multiple life stages and/or hosts, it is critical to have a broad understanding of the parasites' biology to hamper their dissemination. In this context, the RNA interference (RNAi) methodology arose as a research tool in molecular parasitology, enabling the functional characterization of several genes in helminths. Despite the great revolution using CRISPR to interrogate gene function, RNAi has been more widely deployed in diverse parasites. In this review, we will briefly appraise the RNAi mechanistic aspects, describe works that were pioneers in its standardization and application in different helminths species, and extensively explore studies that have successfully used this tool to investigate gene function in helminth parasites.