LIGHT AND ELECTRON MICROSCOPIC INVESTIGATION OF PELOMYXA PRIMA (GRUBER, 1884) (PELOFLAGELLATEA,
PELOBIONTIDA)
Frolov A. O.,1, * Chistyakova L. V.,2 Malysheva M. N.,1
Goodkov A. V. 2, 3
1 Zooloical Insitute RAS, St. Petersburg,
2 Biological Research Institute of St. Petersburg State University, and
3Istitute of Cytology RAS, St. Petersburg, Russia;
* e-mail: frolal@online.ru
Cell organization of a multinuclear pelobiont Pelomyxa prima has been studied at the light and electron
microscopic levels. Motile individuals demonstrate a characteristic drop-like or pyriform shape and reach 550 (ikm in length. The cell
cover is represented by a well-developed, morphologically differentiated glycocalyx 80-100 nm thick. The cytoplasm contains many
structural vacuoles. The nuclei are of vertical type, numbering up to several nuclei in large individuals. Numerous cytoplasmic
microtubules are associated with the external membrane of the nuclear envelope. Separate non-motile flagella are distributed throughout
the cell surface, being more numerous in the posterior body end and uroidal zone of the protist. Basal bodies of the flagella are
extremely long, being deeply immersed into the cytoplasm. These bodies are surrounded by a muff of electron-dense material, with numerous
microtubules radiating from it. A compact bundle of microtubules starts from the base of a basal body axially into the cytoplasm.
Besides, a band-like lateral microtubular rootlet is present. The number of microtubules in the axoneme of undulipodia is unstable.
Neither mitochondria, nor Golgi complex were found. Two species of bacterial endocytobionts are present in the cytoplasm in considerable
numbers.
Key words: Peloflagellatea, Pelobiontida, Pelomyxa prima, Pelomyxa palustris, ultrastructure
|
