Single-cell RNA-seq reveals hidden transcriptional variation in malaria parasites.

Single-cell RNA-sequencing is revolutionising our understanding of seemingly homogeneous cell populations but has not yet been widely applied to single-celled organisms. Transcriptional variation in unicellular malaria parasites from the Plasmodium genus is associated with critical phenotypes including red blood cell invasion and immune evasion, yet transcriptional variation at an individual parasite level has not been examined in depth. Here, we describe the adaptation of a single-cell RNA-sequencing (scRNA-seq) protocol to deconvolute transcriptional variation for more than 500 individual parasites of both rodent and human malaria comprising asexual and sexual life-cycle stages. We uncover previously hidden discrete transcriptional signatures during the pathogenic part of the life cycle, suggesting that expression over development is not as continuous as commonly thought. In transmission stages, we find novel, sex-specific roles for differential expression of contingency gene families that are usually associated with immune evasion and pathogenesis.

Connecting genotypes to medically relevant phenotypes in major vector mosquitoes.

Transmission of mosquito-borne human disease relies on vectors maintaining strong human host preference and continued susceptibility to disease-causing pathogens or parasites. These traits are affected by the genetics and the environments of all involved organisms, and genotypic interactions are common between parasite and vector, and between virus and vector. A recent study on Aedes host preference has exploited natural genetic variation to make great progress. Here I review our current understanding of the genetic basis of transmission-relevant traits in Anopheles and Aedes, highlighting additional research areas that would benefit from the integration of natural genetic variation.