Disruption of rDNA nucleolar clustering and decrease of rDNA transcription in replicative and mitotic stages. (A) FISH analysis of 28S rDNA (green)during 48-h blood-stage cycle. In ring stage (0–18 h post-invasion), rDNA is clustered at one pole of the nucleus, whereas in replicative and dividing stages(trophozoite, 18–38 h and schizont, 38–48 h), the individual rDNA units appear dispersed at multiple sites. (B) Immunofluorescence analysis of PfPol I (red). Ring-stage parasites show a half-moon perinuclear nucleolus. In trophozoites, PfPol I shows an additional diffuse pattern in the nucleoplasm and cytoplasm. In schizont segmented forms, PfPol I appears to relocalize at the nuclear periphery .
Mancio-Silva L, Zhang Q, Scheidig-Benatar C, Scherf A. Clustering of dispersed ribosomal DNA and its role in gene regulation and chromosome-end associations in malaria parasites. Proc Natl Acad Sci U S A. 2010 107(34):15117-22.