title: Tubulin diversity in trophozoites of Giardia lamblia.
abstract: Giardia lamblia is a diplomonad that parasitizes the small intestine of vertebrates. The trophozoite is multiflagellar and its cytoskeleton presents a complex organization of microtubular structures. One of these, the adhesive disk, consists of a microtubular spiral. The median body, whose function is not yet determined, is also composed by microtubules. The cell has eight flagella and two microtubule sheets, known as the funis. In this study we used several antibodies and immunofluorescence microscopy to help in the characterization of these structures. We observed that Giardia tubulin reacts with antibodies raised against very distinct immunogens. The antibodies used were against: (1) alpha-tubulin from chicken embryo brain, Trypanosoma brucei, sea urchin sperm, Paramecium, acetylated alpha-tubulin from Paramecium, and tyrosinated alpha-tubulin, (2) beta-tubulin from chicken embryo brain and Physarum polycephalum, and (3) an antibody with specificity to beta-tubulin having as immunogen the FtsZ bacterial protein. Each cytoskeletal structure of Giardia presented a distinct pattern of labeling by the several antibodies used. These data indicate that even being considered one of the most ancient of organisms, Giardia shares similarities (at least in relation to tubulin) with other organisms. They also open some questions about the organization and composition of its microtubular structures.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Laboratório de Ultraestrutura Celular Hertha Meyer, CCS, Universidade Federal do Rio de Janeiro, Ilha do Fundão, 21940-900 Rio de Janeiro, Brazil.
authors.forename: Loraine
authors.initials: L
authors.lastname: Campanati
authors.forename: Helmut
authors.initials: H
authors.lastname: Troester
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Monteiro-Leal
authors.forename: Herbert
authors.initials: H
authors.lastname: Spring
authors.forename: Michael F
authors.initials: MF
authors.lastname: Trendelenburg
authors.forename: Wanderley
authors.initials: W
authors.lastname: de Souza
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000032:analysis; D016829:Giardia lamblia / Q000737:chemistry* / Q000254:growth & development; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000737:chemistry*; D014404:Tubulin / Q000032:analysis* / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D014404:Tubulin