DNA dynamics in the unusual cell cycle of the malaria parasite Plasmodium falciparum (PlasmoCycle)

Plasmodium is an early-diverging protozoan with a complex lifecycle & unusual cell-biological features. It replicates in its human host by ‘schizogony’: a single parasite generates many nuclei via independent, asynchronous rounds of genome replication prior to cytokinesis. This occurs over ~24hrs inside infected erythrocytes. However, the genome can also be copied extremely rapidly during the sexual cycle in the malaria-transmitting mosquito. Here 8 male gametes are produced from a single gametocyte in less than 10mins, necessitating extraordinarily rapid DNA synthesis. This project will first elucidate the spatio-temporal dynamics of DNA replication in these contrasting cell cycles. To do this, Catherine J. Merrick has developed a method for labelling nascent DNA replication, which was not previously possible in Plasmodium. It will permit: a) a detailed characterisation, at the whole-cell level, of the asynchronous genome replication that occurs in schizogony; b) a study of replication origin spacing & DNA synthesis speed at single-molecule resolution on DNA fibres, comparing these parameters in schizogony & gametogenesis; c) mapping sequences with replication origin activity in the Plasmodium genome; d) investigation of cell-cycle checkpoints & replicative responses to the changing environment in the human host and to antimalarial drugs. These are crucial issues for understanding parasite virulence and drug-resistance, and the work will inform vital new research into transmission-blocking interventions for malaria.

Project details

Basic Science

Jun 2017 — Nov 2023

$2.25M

United Kingdom