Identification of nucleoli in the early branching protist Giardia duodenalis

• Published in: International journal for parasitology Vol. 38; no. 11; pp. 1297 - 1304
• Main Authors: Jiménez-García, Luis Felipe, Zavala, Guadalupe, Chávez-Munguía, Bibiana, Ramos-Godínez, María del Pilar, López-Velázquez, Gabriel, Segura-Valdez, María de Lourdes, Montañez, Cecilia, Hehl, Adrian B., Argüello-García, Raúl, Ortega-Pierres, Guadalupe
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2008; [Oxford; New York]: Elsevier Science; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Cell Nucleolus - metabolism; Cell Nucleolus - ultrastructure; Chromosomal Proteins, Non-Histone - genetics; Diplomonads; Evolution, Molecular; Fundamental and applied biological sciences. Psychology; Giardia; Giardia - metabolism; Giardia - ultrastructure; Giardia duodenalis; Humans; Life cycle. Host-agent relationship. Pathogenesis; Microscopy, Confocal; Microscopy, Electron; Nucleolar organising region; Nucleolus; Nucleolus Organizer Region - metabolism; Nucleolus Organizer Region - ultrastructure; Protozoa; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Ribonucleoproteins; RNA, Ribosomal - genetics; RNA, Ribosomal - metabolism; rRNA processing; Nucleolar organising region; Giardia; Diplomonads; Nucleolus; Ribonucleoproteins; rRNA processing; Protozoa; Ribonucleoprotein; Parasite; Diplomonadida; Ribosomal RNA; Giardia duodenalis; Protista
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2008.04.012

Giardia duodenalis has been described as ‘anucleolated’. In this work we analysed the subcellular distribution of several nucleolar markers in Giardia nuclei using silver and immunostaining techniques for electron and confocal laser microscopy as well as expression of epitope-tagged proteins in transgenic trophozoites. We identified anteronuclear fibrogranular structures corresponding to nucleolar organising regions with recruited ribonucleoprotein complexes, rRNA and epitope-tagged fibrillarin and rRNA-pseudouridine synthase (CBF5). Recombinant fibrillarin and CBF5 were targeted to this subcompartment. This study demonstrates the presence of nucleoli in G. duodenalis and provides a model to analyse minimal requirements for nucleolar assembly and maintenance in eukaryotic cells.