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Protistology ■ 57
1 - Department of Invertebrate Zoology, Faculty of Biology, Saint-Petersburg State University, Uni-versitetskaya emb. 7/9, St. Petersburg, 199034, Russian Federation
2 - Department of Invertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Leninskiye Gory 1—12, Moscow, 119234, Russian Federation
3 - Belozersky Institutefor Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russian Federation [email protected]
Agamococcidians (Agamococcidiorida Levine, 1979) represent an enigmatic group ofApicomplexa. The life cycle of these parasites is characterised by presence of oocysts with sporocysts (similar to coccidian), sporozoites and trophozoites, and by absence of merogony and gamogony. This group combines two families Rhytidocystidae Levine, 1979, parasites of polychaetes, and Gemmocystidae Upton & Peters, 1986, parasites of stony corals. The phylogenetic position of these organisms is still unclear. Previous phylogenetic studies brought agamococcidians together with gregarines and cryptosporidians (Leander, Ramey, 2006; Rueckert, Leander, 2009; Kristmundsson et al., 2011; Cavalier-Smith, 2014). In contrast, morphological data (oocysts with sporocysts and nonmotile trophozoites located within host epithelial tissues) indicate a relationship of agamococcidians with coccidians. We isolated two putative new species of Rhytidocystis from polychaetes Pectinaria hyperborea and Ophelia limacina collected in the Keret Archipelago of the White Sea, Russia. The SSU rDNA sequences obtained from these new parasites clustered strongly with Rhytidocystis cyamus and R. polygordiae within the rhytidocystid clade. Phylogenies inferred from these sequences demonstrate a close relationship between rhytidocystids and marine coccidians. Interestingly, some coccidians closely related to rhytidocystids, such as Margolisiella islandica or Aggregata sp., have all three types of reproduction found among apicomplexans: spo-rogony, merogony and gamogony in their life cycles. Thus, our molecular data agree with known morphological data. We discuss the phylogenetic position and perspectives of further investigations of agamococcidians for more deep understanding of Apicomplexa evolution. Supported by St. Petersburg State University projects (1.42.1493.2015, 1.42.1099.2016).
CAPSASPORA OWCZARZAKIAS A UNICELLULAR MODEL TO STUDY CO-OPTION OF THE ANCESTRAL INTEGRIN ADHESOME Parra-Acero H.1, Harcet M.12, Pérez-Posada A.1, Brown N.H.3, Ruiz-Trillo I.145
1 - Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Catalonia, Spain
2 - Division of molecular biology, Ruder Boskovic Institute, Bijenicka cesta 54, 10 000 Zagreb, Croatia
3 - Dept of Physiology, Development and Neuro-science,University of Cambridge,Downing St, Cambridge CB2 3DY, UK
4 - Departamentde Genética, Universitatde Barcelona, Barcelona, Catalonia, Spain
5 - Institució Catalana de Recerca i Estudis Avangats (ICREA), Barcelona, Catalonia, Spain [email protected]
Adhesion systems and signaling networks are both essential in multicellular organisms. Some elements of the adhesion and signaling pathways of metazoans, such as proteins from the integrin adhesome are conserved in their closest unicellular relatives. This means these proteins already existed in the unicellular ancestor of metazoans and that they were co-opted for a multicellular lifestyle. To understand how the integrin adhesome was co-opted at the onset of Metazoa, we aim to unravel its function in a close unicellular relative of animals, the filasterean Capsaspora owczarzaki. This protist is the closest unicellular relative to metazoans that contains in its genome the basic core ofproteins that constitutes the integrin adhesome. The expression of these proteins is upregulated during the aggregative stage in culture conditions. In order to understand its role, we are developing some molecular and genetic tools, such as immunostaining, transfection, and CRISPR/cas9. We will discuss preliminary data on the localization of several cytoskeletal and adhesion proteins of the integrin adhesome in C. owczarzaki, obtained by overexpression and by immunostaining with antibodies raised against our proteins of interest. We will also discuss the development of CRISPR system in this organism with the aim to develop a complete model system to analyze the origin of animals.
ORAL PROTISTS: IMPORTANCE TO CANINE
PERIODONTAL DISEASE
Patel N.12, Holcombe L.1, Andrew P.2
1 - Mars Petcare UK
2 - University of Leicester [email protected]
58 • "PROTIST—2016
Periodontal disease is one of the most important health concerns for companion animals. Previous studies have demonstrated that at least half of all dogs will have some form of the disease within their lifetime which, without early intervention, can lead to painful periodontal ligament destruction, alveolar bone loss, and eventual loss of teeth. The recent focus of research into canine periodontitis has been the identification and characterisation of the bacterial communities present. However, other microorganisms are known to inhabit the oral cavity and could also influence the disease process. Our recent research has identified two oral protists that can inhabit the canine oral periodontium. Trichomonas sp. and Entamoeba gingivalis were detected using PCR and next generation sequencing and had an overall prevalence of56.52 % (52/92) and 4.34 % (4/92) respectively in UK dogs. Both were statistically associated to animals with periodontal disease indicating their potential involvement in the periodontal disease process. Further work has led to the development of a quantitative PCR assay to measure protist abundance. The qPCR assay has been utilised on plaque samples, collected over a 60 week period from individual teeth of miniature schnauzer dogs (n =52), to investigate longitudinal changes in abundance of both Trichomonas sp. and E. gingivalis as dogs progress from mild gingivitis to early stage periodontitis (<25 % attachment loss). These findings provide the first conclusive evidence for the presence of canine oral protozoa in dog plaque and suggest a possible role for protozoa in the periodontal disease process.
NAKED AMOEBAE OF UKRAINIAN POLIS-SYAFAUNA Patsyuk M.K.
Zhytomyr Ivan Franko State University [email protected]
At present, the naked amoebae of the Kyiv, Zhytomyr and Volyn Polissya fauna are represented by 47 species, which belong to 5 classes, 11 orders, 15 families and 20 species.
According to our research the most distributed in the Ukrainian Polissya waters are: Saccamoeba stagnicola Page, 1974, Korotnevella stella Schaeffer, 1926, Vexillifera sp., Vannella (cf) lata Page, 1988, Cochliopodium sp.(1), Mayorella cantabrigiensis Page, 1983, Thecamoeba striata Penard, 1890, Vahlkampfia sp.(1), Vahlkampfia sp.(2). The such species as Amoeba proteus Leidy, 1878, Polychaos sp., Saccamoeba wakulla Bovee, 1972, Rhizamoeba sp. (2), Cochliopodium sp. (2), Pellita digitata (Greef, 1866) Smirnov et Kudryavtsev, 2004, Mayorella
penardi Page, 1972, Thecamoeba sphaeronucleolus Greef, 1891, Penardia mutabilis Cash, 1904 (have been registered by us in the Volyn Polissya waters), Willaertia sp. and Acanthamoeba sp. (have been registered by us in the Zhytomyr Polissya waters) are less distributed. Among the above listed species 3, which belong to genera Vahlkampfia Chatton et Lalung-Bonnaire, 1912 and Acanthamoeba Vol-konsky, 1931 are parasitic. The 14 naked amoebae morphotypes are registered in the different water-bodies: polytactic, monotactic, flamellian, lens-like, striate, rugose, lingulate, lanceolate, fan-shaped, in the different waters mayorellian, dactylopodial, acanthopodial, branched and eruptive. The amoebae with polytactic and acanthopodial morphotypes might be mentioned as the least distributed.
EFFECT OF THE SPECTRUM OF AVAILABLE NITROGEN SOURCES ON PROROCENT-RUM MINIMUM MORPHOLOGY AND PHYSIOLOGY
Pechkovskaya S.A.12, Matantseva O.V.2, Filatova N.A.2, Telesh I.V.3
1 - Department of microbiology, St. Petersburg State University, Russia
2 - Institute of Cytology RAS, St. Petersburg, Russia
3 - Zoological Institute RAS, St. Petersburg, Russia [email protected]
Dinoflagellates are the prosperous group of aquatic eukaryotes. The ongoing eutrophication of coastal areas provides a competitive advantage to these organisms due to their ability to assimilate nitrogen from a variety of dissolved organic and inorganic sources. The analysis of genomic and transcriptomic databases revealed the presence of transporters and enzymes involved in uptake and assimilation of basic nitrogenous compounds present in seawater in dinoflagellates. In laboratory experiments with the culture of dinoflagellates Prorocentrum minimum, we investigated how the spectrum of available nitrogen sources influences morphological and physiological parameters of cells. We showed that addition of nitrate, ammonium, urea, glycine and their combinations to the culture growing on nitrate causes various physiological cell responses. The incorporation of H3-uridine by dinoflagellate cells revealed an increase in the RNA synthesis rate after the addition of supplementary nitrogen sources to the culture. Remarkably, the extent to which RNA synthesis was enhanced differed depending on the available nitrogen sources. For example, the largest increase in the level of RNA synthesis was achieved in response to addition of the ammonium/urea combination. The analysis of
