CC BY
26
Protistology ■ 49
measures 30^28 ^m and is attached to the bottom of the lorica by a contractile peduncle. The somatic ciliary pattern is of the most complex type, i.e., it comprises a ventral, dorsal, and posterior kinety as well as a right, left, and lateral ciliary field. The ventral kinety has associated an extraordinary ciliary tuft of cell length that extends outside the lorica posteriorly, resembling the golden hair let down from the tower by Rapunzel; T. subacuta is unique in this respect. The right and left ciliary fields are composed of about 11 ciliary rows each, the lateral field consists of invariably 15 rows. While the majority of tintinnids have only two macronucleus nodules, T. subacuta has 4—34, on average 14 nodules. Financially supported by FWF Project P28790.
PROTISTAN VERSUS CYANOBACTERIAL PICOPHYTOPLANKTON PRODUCTION AND GRAZING MORTALITY IN SEVASTOPOL BAY AND ADJACENT WATERS (THE BLACK SEA)
Mukhanov V.S., Rylkova O.A., Sakhon E.G. A.O. Kovalevsky Institute of Marine Biological Research, Russian Academy of Sciences, Nakhimov av. 2, Sevastopol, 299011, Russia v.s.mukhanov@gmail.com
Seasonal dynamics of abundance, specific growth rate, daily production and grazing mortality of the major picophytoplankton components, eukaryotic protists and prokaryotic cyanobacteria, were studied at three stations in Sevastopol bay and adjacent waters (the Black Sea) in 2014 by flow cytometry and dilution method. In the shallow coastal waters, protistan picophytoplankton (PP) dominated (64 ± 23 (SD) %, n=26) the community in terms of abundance (annual average of 16.3 ± 12.4 * 103 cells ml-1), with the latter increasing along the nutrient and pollution gradient from the coastal waters outside the bay (7.3 ± 5.4 * 103 cells ml-1) to the eastern corner ofthe bay (28.7 ± 11.4 * 103 cells ml-1). PP demonstrated significantly lower specific growth rates (0.20 ± 0.19 d-1) and significantly higher daily grazing mortality (4.0 ± 5.8 ^g C l-1 d-1) than cyanobacterial picophytoplankton (0.70 ± 0.46 d-1 and 1.1 ± 1.1 ^g C l-1 d-1, respectively) while the protistan and cyanobacterial daily productions did not differ significantly (paired t-test, p>0.05, n=26). Matter flows through both the community components were comparable to or even exceeded their biomass stocks that indicated high biomass turnover rates. Thus, the protistan component has been shown to play a major role in the community functioning in the Black Sea coastal waters.
THE SPECIALIZATION OF THE PROTO-MITOCHONDRION AS A RESPIRATORY ORGANELLE
Muñoz-Gómez S.A., Roger A.J., Slamovits C.H. Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada. sergio.munoz.@dal.ca
The ancestor of mitochondria was an alpha-proteobacterium whose exact phylogenetic and phenotypic nature remains obscure. Therefore, the proximate selective force that drove the initial endosymbiosis is unknown, even though the ultimate selective advantage was undoubtedly greater efficiency in energy production through aerobic respiration. The specialization of the proto-mitochondrion as the respiratory organelle of eukaryotes required the host to exert increased control over the biogenesis of the newly evolving organelle. Among the several adaptations that transformed the ancestral endosymbiont into a respiratory organelle, two evolutionary innovations were of major importance. The first major innovation was the evolution of mitochondrial cristae to make respiratory sub-compartments. Cristae likely evolved from precursor structures in alpha-proteobacteria. Later molecular innovations further modified cristae to improve their respiratory function. This required the expansion of MICOS (Mitochondrial contact site and Cristae Organizing System) and the evolution of the capability of the ATP synthase complex to form multimers. The second major innovation was the evolution of the ability ofthe host to control the overall morphology, positioning and distribution of mitochondria within the cell. These adaptations optimized bioenergetic output in response to host needs. This was made possible by the origin of mitochondrial fusion, as well as the establishment of interactions between mitochondria and diverse endomembranes and the cytoskeleton. I discuss a detailed evolutionary scenario for the evolution of these two major adaptations in the context of the co-evolutionary integration of mitochondria and their host.
THE ULTRASTRUCTURE OF AMOEBOID
FLAGELLATES AMASTIGOMONAS (CERCO-
ZOA, RHISARIA)
Mylnikov A.A., Mylnikov A.P.
Papanin Institute for Biology of Inland Waters,
Russian Academy of Sciences, Borok, Russia
ap.mylnikov@rambler.ru
The cytoskeleton of three amoeboid flagellates Amastigomonas spp. dwelling in freshwater (one
50 • "PROTIST—2016
strain) and marine waters (two strains) has been considered. The morphology of these strains is relatively similar. The anterior flagellum lies inside the hollow proboscis. The posterior flagellum goes along the ventral groove. Two heterodynamic flagella are smooth and have not been covered by any structures. The transitional zone of the flagella do not contain additional elements and are ofthe usual structure. The microtubule band and anterior rootlet are inserted from the kinetosome of the anterior flagellum, the microtubule right and left rootlets and single rootlet are inserted from the kinetosome of the posterior flagellum. The kinerosomes are located at obtuse angle or antiparallel and connected by the three fibrils and cross-striated structure. The rhizoplast has not been found. The thickened cell coverings consist of plasmalemma and epiplasm. The margins of the coverings form the folds, the ventral groove goes between them and is bounded only by the plasmalemma. The vesicular nucleus and Golgi apparatus are of the usual structure. The mitochondria contain tubular cristae. The pseudopodia inserting from ventral groove serve to capture bacteria. Front cytoplasmic outgrowth have been found for the first time. The resemblance and differences ofgiven species with other apusomonads have been shown. This study was supported by the Russian Foundation for Basic Research (grant nos. 14-04-00500, 14-04-00554, 15-29-02518).
THE ULTRASTRUCTURE OF AMOEBOID FLAGELLATE THAUMATOMONAS COLO-NIENSIS WYLEZICH ET AL. 2007 (CERCO-ZOA, RHIZARIA) Mylnikov A.P., Prokina K.I. Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia ap.mylnikov@rambler.ru
The ultrathin structure of amoeboid flagellate Th. coloniensis has been considered. The cell is surrounded by somatic scales which forming on the surface of the mitochondria. The heterodynamic flagella emerge from the small flagellar pocket. Both flagella are covered by the cone—shaped scales and thin twisted mastigonemes. The kinetosomes lie parallel to each other. The transitional zone of the flagella contains the thin—walled cylinder. The transversal plate of the flagella is located above cell surface. The flagellar root system consists of 3 microtubular bands and fibrillar rhizoplast. The vesicular nucleus and Golgi apparatus are of the usual structure. The mitochondria contain the tubular cristae. The extrusive organelles (kineto-cysts) which contain the amorphous material and capsule have been found in cytoplasm. The capsule
consists of the muff and cylinder. Osmiophilic bodies of various shapes contain crystalloid inclusions. The pseudopodia capturing the bacteria are inserted ventrally. The groove is armored by the two longitudinal groups of closely situated microtubules. Microbodies and symbiotic bacteria have not been observed. Th. coloniensis differs from other Thaumatomonas species by the presence of osmiophlic bodies and absence ofmicrobodies. This study was supported by the Russian Foundation for Basic Research (grant nos. 14-04-00500, 14-0400554,15-29-02518).
PLANKTONIC CILIATES OF THE SHEKSNA
RESERVOIR
Mylnikova Z.M.
Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia m.mylnikova@rambler.ru
The species composition, abundance, biomass and distribution of planktonic ciliates across the Sheksna Reservoir consisting of three parts have been studied. Fifteen species of ciliates, belonging to four classes: Spirotrichea - 6, Litostomatea - 4, Prostomatea - 4, Oligohymenophorea - 1 were recorded during the observation period in the pelagic zone. The maximal number of species (11) was registered in Beloye Lake, minimal one (6) - in Kovzhinsk part. The following species: Tintinnidium fluviatile, Codonella cratera, Limnostrombidium viride, L. pelagica and Rimostrombidium velox were dominants in the most part of sampling points. Paradileptus conicus, Monodinium balbiani, Enchelis pupa and Prorodon ovum were registered less frequently and in small quantities , and has been recorded for the first time on this site. The maximal average abundance (2502 * 103 ind./m3) and biomass (141 mg/m3) were registered in Beloye Lake. The maximal density (27 50-4 150 * 103 ind./ m3 and 156-352 mg/m3) observed in shallow waters of the western coast, in sampling points Mandoma, Kustovo, Kium-Mandoma and Belozersk. Lower density (1150-1250 * 103 ind./m3 and 62-90 mg/ m3) observed in sampling points near the center of the lake, and Sudovoy Khod station. The average values of abundance and biomass of Sheksna Reservoir accounted 1875000 ind./m3 and 123 mg/ m3, respectively. The trophic status of the Sheksna Reservoir during the study period can be described as mesosaprobic.
PUF PROTEINS IN GIARDIAINTESTINALIS Najdrova V., Dolezal P.
Department of Parasitology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
