Fig. 4

The nucleolus is a nuclear body located at the nuclear periphery of E. histolytica. a Anti-fibrillarin antibody was incubated with nuclear extract from E. histolytica. A protein of approximately 35 kDa was identified. b Indirect Immunofluorescence assays (IFAs) were performed using anti-fibrillarin antibody (green), and the nuclei were stained with DAPI (blue). Three different signal patterns were obtained with this antibody. In the first, the nucleus was found to be located in the periphery of the nucleus. In the second, the fibrillarin was located to one side of the nucleus, while in the third, the fibrillarin was found in two poles of the nucleus. Representative IFAs of the three types of signals are shown. c IFA analysis of nucleolin. The nucleolin antibody displays three different patterns: in the majority of trophozoites (50 %), the nucleolin is present at the nuclear periphery. In other images (35 %), the nucleolin is present at one pole of the nucleus. Finally, in the remaining trophozoites, the nucleolin is located on 2 sides of the nucleus (15 %). The nucleus was detected by DAPI staining (blue). The scale bar is indicated in each image. d Dual-color IFA with anti-mouse fibrillarin (green) and anti-rabbit nucleolin (red). Fibrillarin and nucleolin co-localize in the nucleus of E. histolytica in the three types of signals (yellow). e Western blot assay. Anti-lamin B1 antibody was incubated with nuclear extracts from E. histolytica and recognized a protein of approximately 78 kDa. f IFAs were carried out with antibodies against lamin B1. The nuclei were stained with DAPI (blue). The IFA showed that lamin is located around the nucleus in E. histolytica. g Fibrillarin (red) and anti-lamin B1 (green) co-localize (yellow) at the nuclear periphery in E. histolytica only when the fibrillarin is present around the nucleus. The scale bar is indicated in each figure. A representative image of three independent experiments is shown