Sequence-dependent heterochromatin formation in the human malaria parasite Plasmodium falciparum

The human malaria parasite Plasmodium falciparum represses transcription of the gene encoding AP2-G, which is master regulator germ cell differentiation, via heterochromatin condensation following histone H3 lysine 9 trimethylation (H3K9me3). Although H3K9me3-marked typically constitutive and its establishment depends on RNA interference (RNAi) pathway in fission yeast centromeres, parasites lack molecular members essential for RNAi. We developed a strategy to assess artificial chromosomes introduced into P. falciparum. show that particular DNA sequence AP2-G promoter able induce de novo H3K9me3 nucleosome deposition. In addition, we also found contains distinct element required maintenance repression memory. Thus, speculate have evolutionarily acquired sequence-dependent system non-constitutive, i.e. facultative, heterochromatin.