A single-cell sequencing approach to understand P. vivax gene regulation at the epigenetic level.

Malaria parasites employ an epigenetic bet-hedging strategy for rapid adaptation to changing host environments, based on transcriptional heterogeneity as grounds for natural selection. Plasmodium vivax, responsible for one third of the malaria cases outside of Africa, cannot be continuously cultured, and this has seriously obstructed progress in epigenetic research. Leveraging recent advancements in single-cell techniques, this study aims to investigate P. vivax blood stage regulation at the epigenetic level for the first time, and investigate its adaptive role. I aim to single-cell sequence both the transcriptional and heterochromatin profile from P. vivax patient isolates. This way, transcriptional heterogeneity in genetically identical parasite infections can be observed and linked to the underlying epigenetic profile, revealing which P. vivax genes are regulated at the epigenetic level. To uncover the adaptive advantage of transcriptional heterogeneity, I will specifically focus on the TRAg multigene family which has a role in erythrocyte invasion, using a P. knowlesi model. I will test whether specific TRAg gene expression patterns are selected by host environmental factors that affect invasion (RBC receptor polymorphisms, immunity), resulting in an increased fitness of the parasite population. This way, I aim to unravel genome-wide regulation at the epigenetic level in P. vivax and shed light on the adaptive role of epigenetics in the TRAg family.