Epigenetics in Apicomplexa: control of gene expression during cell cycle progression, differentiation and antigenic variation.

Apicomplexan parasites are important disease causing organisms that infect both animals and humans, causing extensive health and economic damage to human populations, particularly those in the developing world. The ability to perform genetic crosses, to engineer transgenic parasites lines, and the wealth of information made available through recent genome sequencing projects have made the laboratory study of these parasites important not only for understanding the diseases that they cause, but also for gaining insights into basic biological processes. The control of gene expression and cellular differentiation are particularly interesting in these organisms, as the apparent lack of large families of recognizable transcription factors typically found in other eukaryotic organisms suggests that they may be unusually reliant on epigenetic mechanisms. Here we review recent advances in the study of epigenetic gene regulation in the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii.