Immunofluorescence analysis of trophozoite stage parasites shows that Pf H2B.Z (green) is expressed in the nucleus and overlaps with PfH2A.Z and the histone modification H3K4me3, but not with the heterochromatin mark H3K9me3 (red). The DNA was labelled with DAPI(blue). Pf H2B.Z and Pf H2A.Z colocalize very well and thus occupy the same subnuclear region, which largely overlaps with the DAPI-stained DNA except for a small area in which alternative histone staining was less intense. Pf H2B.Z also colocalized with the euchromatin marker H3K4me3, but not with the heterochromatin marker H3K9me3.Petter M, Selvarajah SA, Lee CC, Chin WH, Gupta AP, Bozdech Z, Brown GV, Duffy MF. H2A.Z and H2B.Z double-variant nucleosomes define intergenic regions and dynamically occupy var gene promoters in the malaria parasite Plasmodium falciparum. Mol Microbiol. 2013 87(6):1167-82

PfH2A.Z is present in the euchromatin compartment. Immunoelectronmicroscopy with anti-PfH2A.Z antibodies indicates nuclear compartmentalization of PfH2A.Z. N = nucleus, C = cytoplasm.Petter M, Lee CC, Byrne TJ, Boysen KE, Volz J, Ralph SA, Cowman AF, Brown GV, Duffy MF. Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter. PLoS Pathog. 2011 7(2):e1001292. 17.

Nuclear localization of PfH2A.ZGFP. Confocal microscopy of PfH2A.ZGFP parasites at the (A) merozoite, (B) ring, (C) trophozoite and (D) schizont stage. Blue: DNA stained with DAPI. Green: PfH2A.ZGFP. Overlays in the lower panels in each picture demonstrate the nuclear localization of PfH2A.ZGFP. The transgenic P. falciparum ectopically expressing PfH2A.Z-GFP fusion proteins corroborated the sub-nuclear distribution of PfH2A.Z.Petter M, Lee CC, Byrne TJ, Boysen KE, Volz J, Ralph SA, Cowman AF, Brown GV, Duffy MF. Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter. PLoS Pathog. 2011 7(2):e1001292. 17.

Upper panel: PfH2A.Z is expressed in the nucleus throughout asexual differentiation. Full length PfH2A.Z was expressed as a GSTfusion protein in E. coli and used to immunize rabbits. Nuclear localization of PfH2A.Z is shown by indirect immunofluorescence analysis and confocal microscopy of fixed 3D7 parasites using anti-PfH2A.Z antibodies. DNA was visualized with DAPI. R = ring stage, T =trophozoite stage, S = schizont stage. DIC = differential interference contrast. An area stained with the DNA dye DAPI but devoid of PfH2A.Z labelling was consistently observed, indicating that PfH2A.Z is enriched towards one side of the nucleus.Lower panel: Colocalization analysis shows PfH2A.Z overlap with the euchromatin marks H3K9ac and H3K4me3 but not with the subtelomeric heterochromatin marks H3K9me3 and HP1. PfH2A.Z, H3K4me3, H3K9ac and H3K9me3 were detected with specific antibodies.Petter M, Lee CC, Byrne TJ, Boysen KE, Volz J, Ralph SA, Cowman AF, Brown GV, Duffy MF. Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter. PLoS Pathog. 2011 7(2):e1001292. 17.