Orc1 localizes to telomeric foci and the nucleolus. (A) Double IF using anti-rabbit Orc1 (red) and anti-rat Sir2 (green). Orc1 is preferentially localized at the periphery of the parasite nucleus and colocalizes with Sir2 signals. (B) Dual-colour IF by using anti-rabbit Orc1 (red) and anti-rat Nop1 (green). A fraction of Orc1 signals colocalize with Nop1, suggesting that Orc1 also localizes in the nucleolus of the parasite. (A,B) Parasites are in ring stage and nuclear DNA was stained with DAPI (blue). Scale bars: 1 μm. Mancio-Silva L, Rojas-Meza AP, Vargas M, Scherf A, Hernandez-Rivas R. Differential association of Orc1 and Sir2 proteins to telomeric domains in Plasmodium falciparum. J Cell Sci. 2008 Jun 15;121(Pt 12):2046-53. doi: 10.1242/jcs.026427.