Ref ID : 7674
Guy Brugerolle; [Caracteres Ultrastructuraux d'une Mastigamibe: Mastigina hylae (Frenzel)]. Protistologica XVIII(2):227-235, 1982
Reprint
In File
Notes
The cell ultrastructure of Mastigina hylae fits very well with Collin's and Becker's descriptions (1913, 1925). The nucleus is attached to the flagellum by fibres forming a nucleo-flagellar complex comprising a MTOC which gives rise to a rhizostyle and to a cape of microtubules covering the nucleus. The axoneme of the inactive flagellum is larger and composed of microtubules in disorder. Only one kinetosome is present. The rhizostyle is laterally directed and composed of a sheet of microtubules and by several accessory bundles of microtubules. The cape made by free microtubules covers the nucleus; these microtubules are surrounded by microfibrils which link them to each other and to the external nuclear membrane. The secondary nuclei are associated with a very reduced nucleo-flagellar complex. The cytoplasm contains large digestive vacuoles but no mitochondria nor a Golgi apparatus and no contractile microfilaments are visible. The nucleus bears a large endosome corresponding to a nucleolus; the nuclear envelope shows a classical structure and numerous nuclear pores. Mitosis and cysts have not been observed. This Mastigamoebae with a continuous single flagellum and a kinetosome really corresponds to a species and belongs to a group of Protozoa different from the swarm-cells of Myxomycetes and from the Amoeboflagellates with a temporary flagellate stage (Naegleria and Tetramitus) and from the well known groups of Flagellates. Its systematic position among the Zoomastigophora in a newly revised order Rhizomastigida or among the Rhizopoda Lobosea is discussed.