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Euplotes daidaleos and its endocytobionts
Author(s) -
FOKIN SERGEI I.
Publication year - 2005
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2005.05202003_6_7.x
Subject(s) - biology , ciliate , chlorella , protozoa , ciliata , eubacterium , botany , algae , paramecium , bacteria , ecology , genetics , microbiology and biotechnology
Among almost 200 endocytobiotic associations between freshwater ciliates and Chlorella ‐like algae (A) one Euplotes species— E. daidaleos Diller, Kounaris, 1966 is existing. It was not so far under particular investigation. Comparative study of cell morphology and behavior of “green” and derived from it “white” stocks of the ciliate (C), collected in Italy and Russia were carried out, using light and electron microscopy. The green C usually maintain 30–80 units of A and some bacteria (B), belonging to the different types— Polynucleobacter ‐like bacterium, β‐subgroup of Proteobacteria (size about 2−10 × 0.4−0.5 μm) and another eubacterium (size 1−2 × 0.6−0.8 μm). The number of the first B was much higher in the white C, but could vary between different host cells. According to data obtained with fluorescent microscopy it looks like these B can produce long chains, which consisted of quite short individuals with only one nucleoid. Association between Euplotes and Chlorella within the system is rather a close one: loss of the A after long time cultivation of C in darkness usually did not happen. The majority of the ciliates (96–100%) kept A, but this number often dropped down, apparently as a result of digestion by C of some of the A. Positive phototaxis is almost absent in green E. daidaleos in comparison with that of Paramecium bursaria–Chlorella association. The rate of division was not significantly deviated according to A presence. Moreover, cells of the green Euplotes did not like high level of illumination and in any cases needed some additional food. This situation is also quite opposite to the P . bursaria–Chlorella system. In between 2 and 3 months of cultivation, the main part of the white stocks have lost its viability partly because of disturbance in the cirral pattern. In about 90% of cells some frontal, ventral, transversal and caudal cirri disappeared in different combinations. It is the first indication on some connection between A‐symbionts and host morphogenesis. Large food vacuoles almost all time presented in such cells show some kind of problems with digestion as well. E. daidaleos could be considered as three‐lateral symbiotic system, promising for further investigations.