Structure and division of the Golgi complex in Trichomonas vaginalis and Tritrichomonas foetus

We present observations on the fine structure and the division process of t he Golgi complex in the protists Trichomonas vaginalis and Tritrichomonas f oetus, parasites of the urogenital tract of humans and cattle, respectively . The Golgi in trichomonads is a prominent structure, associated with stria ted parabasal filaments to which this organelle seems to be connected. We f ollowed by immunofluorescence and electron microscopy the Golgi in interpha sic and mitotic cells. Ultrastructural studies were performed using fast-fr eezing fixation, immunocytochemistry using antisera to the known adhesins A P65 and AP51, cytochemistry (acid phosphatase, Ca-ATPase, zinc iodide-osmiu m tetroxide technique (ZIO), for analysis of distribution of the endoplasmi c reticulum and Golgi complex, and Thiery's techniques), routine and serial thin-sections. Three-dimensional reconstruction, NBD-ceramide, fluorescent lectin (WGA) and nocodazole treatments were also used. We demonstrate that : (1) the Golgi in trichomonads is a single-copy organelle; (2) presents a fenestrated structure; (3) is formed by 8-12 saccules; (4) is connected to the parabasal filaments by thin filamentous bridges; (5) by cytochemistry, presents a positive reaction for the lectin WGA, Ca++-ATPase, acid phosphat ase, ZIO and Thiery's techniques; (6) does not appear to break down at any point of the cell cycle; (7) elongates during the cell cycle by lateral gro wth; (8) is labeled by anti-glutamylated tubulin antibodies, but it is not fragmented by nocodazole treatment; (9) before mitosis, the already elongat ed Golgi ribbon undergoes progressive medial fission, cisternae by cisterna e, starting at the cisternae adjacent to the cell surface and ending with t he cis-most cisternae; (10) the Golgikinesis originates two small Golgi rib bons; (11) the Golgi is intensely labeled with the antisera to the AP65 and AP51 adhesins in T. vaginalis, thus seeming to be a key station in the pro duction of adhesins.