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Protistology ■ 61
P. caudatum. Infection by H. caryophila sometimes kills paramecia, but stable association may last for many years. These premises led to detailed investigation of 6 isolates of H. caryophila, 4 ofthem inhabiting the species of the P. aurelia complex, and 2 found in P. caudatum. Screening of more than 70 potential hosts — strains belonging to 10 morphological species of Paramecium — showed that H. caryophila can infect majority of species of the P. aurelia complex, P. jenningsi, P. caudatum, P. multimicronucleatum, and P. putrinum. Symbiosis could be formed only in certain combinations ofthe host and the symbiont, though some strains appeared to be universal recipients for all H. caryophila isolates studied. However, most of the checked strains were never infected. P. caudatum strains often died during infection by H. caryophila isolated from P. aurelia strains. Thus, the chance that symbiont can not develop in host or kills it is higher than possibility of successful infection, explaining why ciliates harboring symbiotic bacteria are rather rare in nature. Molecular phylogenetic analysis of 16S rDNA sequences proved that phylogenetic relationships of H. caryophila with other Holospora species are quite distant. Physiological and phylogenetic features support transfer of H. caryophila to the new genus Preeria.
Supported by RFBR 16-04-01195.
CHASING ION CHANNELS OF DINOFLA-GELLATES
Pozdnyakov I., Matantseva O., Skarlato S. Institute ofCytology RAS, St. Petersburg, Russia [email protected]
Ion channels are transmembrane protein complexes permeable for ions and playing a crucial role in cell physiology. Ion channels of animals, plants and fungi have been intensively studied for many decades; however, noticeably less information is available concerning ion channels of other eukaryotes. This lack of knowledge hampers our understanding of both evolution of ion transport and physiology of protists. Dinoflagellates are the group of aquatic unicellular eukaryotes of high ecological relevance, but rather little is known about their physiology. At the same time, dinoflagellates are phylogenetically distant from animals, plants and fungi and thus are attractive objects to study evolution of ion channels. However, investigation of dinoflagellate ion channels is complicated by the lack of sufficient genomic data and obstacles in applying electrophysiological techniques to dinoflagellates due to their complex cell coverings. We analyzed publicly available transcriptomes of ten dinoflagellate species and found 12 ion channel
families, including four-domain voltage-gated ion channels (FDVGIC) that played a crucial role in evolution of exciting membranes of eukaryotes and nervous system in metazoans. We revealed a high degree of phylogenetic, structural and functional diversity in FDVGIC of dinoflagellates. We developed a new method to produce spheroplasts of armored dinoflagellates and for the first time obtained single-channel recordings oftheir ion channels. Our method allowed us to detect considerable diversity of cation channels in Prorocentrum minimum at the electrophysiological level: potassium-selective channels, inwardly rectifying cation channels, "fast" and "slow" cation channels, and nonselective cation channels. Funded by the Russian Science Foundation, project 16-14-10116.
PHYLOGENY OF PROTISTAN FOUR-DOMAIN VOLTAGE-GATED ION CHANNELS Pozdnyakov I., Skarlato S. Institute ofCytology RAS, St. Petersburg, Russia [email protected]
Four-domain voltage-gated ion channels (FDV GIC) drive the initial phase of the action potential propagation in metazoans and many protists. Therefore, these channels are considered as major players in evolution of eukaryotic excitability and metazoan nervous system. In addition to cellular excitability, they are important for cellular motility, intracellular signaling and regulation of rhythmical activity. There are five well studied subfamilies of FDVGIC, and all of them are associated with the opisthokont lineage: voltage-gated and voltage-insensitive sodium channels (Nav and NALCN, respectively), as well as voltage-gated calcium channels (LVA-Cav and HVA-Cav) and voltage-insensitive calcium channels of fungi (Cch). Using publicly available genomic, transcriptomic and protein databases and blast search, we identified 277 members of FDVGIC family from different eukaryotic groups to reconstruct phylogeny of this ion channel family employing the maximal likelihood (ML) method and Bayesian analysis (BA). In this work, we demonstrated that most ofthe considered protist groups have their own subfamilies of FDVGIC that do not form clades with any known subfamily ofFDVGIC (i.e. Nav, NALCN, LVA-Cav, HVA-Cav, and Cch). Moreover, both ML and BA approaches showed that similar to metazoans some protist groups, such as alveolates and stramenopiles, possess high phylogenetic diversity of FDVGIC. Although obtained phylogenies are not fully resolved due to the limited data on ion channel sequences, the present study advances our understanding of the diversity and evolution of FDVGIC family. Funded
62 • "PROTIST—2016
by the Russian Science Foundation, project 16-1410116.
HETEROTROPHIC FLAGELLATES OF SPHAGNUM BOGS IN SOUTH PATAGONIA, CHILE Prokina K.I.1, Mylnikov A.P.1, Philippov D.A.12
1 - Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Nekouzsky District, Yaroslavl Oblast, 152742Russia
2 - Tyumen State Universsity, Tyumen, 630003Russia [email protected]
Bogs are habitats of great environment-modifying value, in particular, play a major role in the formation of the hydrological regime of the surrounding territory. A considerable amount of data has been accumulated on the heterotrophic flagellates associated with wetland ecosystems of the Northern Hemisphere while the large wetlands of the south part of South America remain almost unexplored. Species composition and morphology of heterotrophic flagellates collected from six sphagnum bogs in Chilean part of South Patagonia and Tierra del Fuego in October—November 2015 are described. Fifty-eight species from 33 genera and 3 macrotaxa (Opisthokonta, SAR, Excavata) and heterotrophic flagellates 'incertae sedis' have been recorded. Most of the recorded species are bacterivorous, 7 species — are omnivorous, and 1 — is a predator, feeding on other flagellates. In two bogs of continental part of Chile we have recorded 38 species and forms (38 species in bog no. 1; 1 species in drained bog no. 2), and in four bogs in Tierra del Fuego — we have recorded 39 species and forms (15 species in bog no. 3; 8 species in no. 4; 13 species in no. 5; 16 species in no. 6). Among all aquatic habitats associated with bogs, the greatest number of species has been recorded in hollows (35 species); bogs streams (25); small boggy lakes (24); pool near trunks of Nothofagus and peat excavation with cyanobacterial mat at the bottom (5); only 1 species has been recorded in a drainage canal. All identified flagellates are known from different types offreshwater habitats of the Northern Hemisphere, and most of them (31 species and 10 not identified to species level taxa are known from the bogs of the Northern Hemisphere.
This study was supported by the Russian Science Foundation (project no. 14-14-01134).
ATTRIBUTABLE RISK OF CAPILLARIA SPECIES IN DOMESTIC PIGEONS (COLUMBA LIVIA DOMESTICA) Qamar M.F.Q.12, Arifa Butt A.B.2
1 - University of Veterinary & Animal Sciences, Lahore
2 - Department of Zoology, GC University Lahore
Fecal samples were collected from 120 domestic pigeons to determine the Attributable risk of Ca-pillaria spp. The Capillaria spp. was observed in 64 out of 120 (51%) pigeons (70 males and 50 females) under study. A total of 64 (39 males and 25 females) were naturally infected with Capillaria spp. with 51% and 50% in males and females respectively. Qualitative examinations include the direct microscopy and faecal floatation while quantitative examination includes McMaster technique (worms are calculated per gram of the faeces). Month wise Attributable risk showed that eggs of the worms were found to be abundant in the month of July (60% to 73%) because of high humidity in the month of July during the present study. Very high and very low temperature is not suitable for the proper development of the eggs. Qualitative and quantitative examination revealed that Capillaria spp. was more prevalent in males (51%) than females (50%) but overall there is no significant difference (p>0.05) in the male and female because both of individuals invest equal amount of energy in search of food and incubating the eggs. Different breeds of the pigeons gave different Attributable risk in different months during the whole study. Group of pigeons from different locations showed variable Attributable risk. Areas with high humidity were more suitable for the development of eggs that is the reason that higher Attributable risk was observed in shahdara (75%).
NEBELA JIUHUENSIS NOV. SP. (AMOEBO-ZOA; ARCELLINIDA; HYALOSPHENIIDAE): A NEW MEMBER OF THE NEBELA SACCI-FERA - EQUICALCEUS - ANSATA GROUP DESCRIBED FROM SPHAGNUM PEAT-LANDS IN SOUTH-CENTRAL CHINA Qin Yangmin123, Man Baiying2, Anush Kosakyan4, Enrique Lara3, Gu Yansheng2, Wang Hongmei2, Zhang Wenwen12, Edward A.D. Mitchell56
1 - Department ofGeography, School ofEarth Science, China University of Geosciences, Wuhan, 430074, China
2 - State Key Laboratory of Biogeology and Environmental Geology, China University ofGeosciences, Wuhan, 430074, China
3 - Laboratory ofSoilBiology, University ofNeuchatel, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
4 - Department of Zoology, Institute of Biosciences, University of Sao Paulo, Rua do Matao, travessa 14, Sso Paulo, Brazil
5 - Laboratory ofSoil Biology, University ofNeuchatel, Rue Emile Argand 11, CH-2000 Neuchatel, Swit-
