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30 • "PROTIST—2016
OBSERVATION OF ZOOSPORE SETTLEMENT FOCUSING ON THE DEVELOPMENT OF ACTIN FILAMENTS (LABYRINTHULEA, STRAMENOPILES)
Iwata I.12, Kimura K.3, Tomaru Y.4, Motomura T.5, Koike Kana6, Koike Kazu7, Honda D.28
1 - Graduate School of Natural Science, Konan University, Japan
2 - Institute for Integrative Neurobiology, Konan University, Japan
3 - Institute of Lowland and Marine Research, Saga University, Japan
4 - National Research Institute of Fisheries and Environment ofInland Sea, Japan Fisheries Research and Education Agency, Japan
5 - Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Japan
6 - Natural Science Center for Basic Research and Development, Hiroshima University, Japan
7 - Graduate School of Biosphere Science, Hiroshima University, Japan
8 - Faculty of Science and Engineering, Konan University, Japan [email protected]
The Labyrinthulea is characterized by an ectoplas-mic net (EN) system. The nets are superficially similar to narrow pseudopods of many protists but different in the following points: their origin from a unique organelle named the bothrosome, membrane invagination along EN, and absence of mitochondria and ribosomes. The bothrosome is located near the cell surface and is a complex ofthe electron dense material and the endoplasmic reticulum. Previously we observed, by immunofluorescence staining, that the actin filaments are located in EN. In this study, we investigated the process from a zoospore to a vegetative cell of Schizochytrium aggregatum, especially focusing on the development of the bothrosome and behavior of actin filaments. After the flagella were drawn into the cell, the bothrosome appeared de novo at the anterior-ventral region of the cell. After the zoospore settled and rounded, the actin appeared as a spot in the same position of the newly appeared bothrosome by immunofluorescence staining. It was expected that the electron dense material of the bothrosome is the organizing center of the actin filaments. However, under immunoelectron microscopy, reaction by the anti-actin antibody was observed in EN and cytoplasm around the bothrosome, not in the electron dense material of the bothrosome. It was suggested that the function of the bothrosome is not nucleation of actin filaments. We expect that actin relates to morphogenesis of EN, that is, the actin filaments probably play an important role ofpulling
the endoplasmic reticulum to the bothrosome and stretching the membrane invagination along EN.
MULTIGENE PHYLOGENY OF SYNURA (SYNUROPHYCEAE) AND DESCRIPTIONS OF FOUR NEW SPECIES BASED ON MORPHOLOGICAL AND DNA EVIDENCE Jo B.Y.1, Kim J.I.1, Skaloud P.2, Siver P.A.3, Shin W.1
1 - Department of Biology, Chungnam National University, Daejeon 305-764, Korea
2 - Department ofBotany, Faculty ofScience, Charles University, Benatska 2, Prague 2, CZ-12801, Czech Republic
3 - Department ofBotany, Connecticut College, New London, Connecticut 06320, USA [email protected]
We used phylogenetic analyses based on multiple gene sequences (partial nr SSU and LSU rDNA, partial pt LSU rDNA, psaA, and rbcL) from 148 strains (including three outgroups) and scale ultrastructure to examine phylogenetic relationships among species of the colonial genera Synura and Tessellaria. The phylogenetic tree based on the combined dataset was congruent with ultrastructural characteristics of the scales. Synura was divided into three major clades, two including species in section Synura, and one representing section Peterseniae. One clade, consisting of seven strains of S. uvella (section Synura), diverged at the base of the genus. The second clade consisted of the remaining species belonging to the section Synura. The third clade, containing organisms in the section Peterseniae and characterized by scales possessing a keel, was monophyletic with strong support values. Based on our findings, S. uvella needs to be in a separate section from other spine-bearing species, and we therefore propose new sectional ranks; Synura, Peterseniae, Curtispinae (presence of body scales with slender spines, tubular scales, and caudal scales). We further propose four new species based on phylogenetic analyses and unique scale characters; S. longitubularis sp. nov., S. sungminbooi sp. nov., S. soroconopea sp. nov., and S. lanceolata sp. nov.
CORRELATION BETWEEN FRESH WATER
CILIATED PROTIST COMMUNITIES AND
THEIR MICRO-ECOLOGY
Kamra Komal1, Kaur Harpreet1, Tripathi Charu2,
Kaur Surinder1, Narula Laxmi1, Lal Rup2, Warren
Alan3
1 - Ciliate Biology Lab, SGTB Khalsa College, University of Delhi, Delhi 110007
2 - Department of Zoology, University of Delhi, Delhi
Protistology ■ 31
110007
3 - Natural History Museum, London, SW7 5BD, UK [email protected]
River Yamuna maintains a reasonably good quality from its origin in the Himalayas to its entry into the National Capital Region (NCR) of Delhi, India. 18 sewage drains carrying industrial and domestic wastes flow into the river in the 22 km stretch (1.6% of total length) as it flows through the NCR. 80% of the pollution in the river's total length of 1375 km occurs as it passes through the NCR, severely compromising its water quality. As free-living ciliated protist species differ widely in tolerance to pollutants, the present study was conducted to catalogue ciliate communities (with appropriate morphological, morphometric and morphogenetic descriptions) at two selected locations along the river, namely the point where the river enters the NCR (S1) and 500 m downstream of the site where the largest sewage drain empties into the river (S2). Physico-chemical parameters including heavy metal concentrations were analyzed in order to assess the water quality at these two locations. Compared to S1: the Biochemical Oxygen Demand and phosphate concentrations increased 5X at S2; total hardness, total dissolved solids, conductivity, turbidity and nitrates doubled at S2; total coliforms and faecal coliform increased 50X at S2; lead concentration increased 2X times and arsenic 3X at S2. There was a significant fall in the species richness and abundance of ciliated protists at S2. Ofthe hypotrichous ciliates, there was a significant loss of members of the family Oxytrichidae, whereas euplotid populations were maintained. The changes in ciliate community will be discussed with respect to water quality.
NEW DATA ON THE ULTRASTRUCTURE OF THE GENUS PARADERMAMOEBA: UNUSUAL FEEDING MODE AND PRESENCE OF CYTOPLASMIC MTOCS Kamyshatskaya O.G., Smirnov A.V. Departmentoflnvertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia [email protected] Naked amoebae engulf food objects via phagocytosis, and during this process the portion of cell membrane covered with the glycocalyx appears inside newly formed food vacuoles. Further cell has to restore membrane and reconstruct respective portion of the glycocalyx. It may be an energetically costly process for species possessing thick and highly differentiated glycocalyx. Genus Paradermamoeba (phylum Amoebozoa, class Discosea) includes two species — P. levis and P. valamo. Both possess highly differentiated cell coat composed of tightly
packed helical glycostyles, ca. 220 nm in thickness in P. levis and ca. 520 nm in P. valamo. Our study reveals that during formation of the food vacuole P. valamo resorbs cell coat at the area of contact with food object, thus avoiding digestion of glycocalyx elements. The similar feeding mode is known in other thick-coated amoebae, like Pellita and Dermamoeba. This observation confirms our earlier hypothesis, stating that thick-coated amoebae have to adopt special ways to avoid energetically costly digestion and further reconstruction of glycocalyx elements. We provide the first description of the cytoplasmic microtubule-organising centres (MTOCs) associated with dictyosomes ofthe Golgi complex in genus Paradermamoeba. This finding confirms the hypothesis that presence of cytoplasmic MTOCs is a synapomorphy of the phylogenetic lineages forming the subclass Longamoebia. Detailed study of the ultrastructure of P. levis reveals that so-called "supernumerary nucleus" of P. levis noted in the initial description is not an individual structure but an outgrowth of the cell nucleus containing its own nucleolus. Supported with RSF grant 14-14-00474.
ISOLATION OF FREE-LIVING AMOEBAE FROM SOUTHERN HAN-LIVER IN KOREA Kang H.K.12, Seong G.S.12, Sohn H.J.1-2, Jung S.Y.3, Lee S.E.4, Park M.Y.4, Shin H.J.12
1 - DepartmentofMicrobiology, Ajou University School of Medicine
2 - Department of Biomedical Science, Graduate School of Ajou University, Suwon 443-721, Republic of Korea
3 - Department of Biomedical Laboratory Science, Molecular Diagnostics Research Institute, School of Health and Medicine, Namseoul University, Cheonan 31020, Republic of Korea
4 - Division of Malaria and Parasitic Disease, Korea National Institute ofHealth, Osong363-951, Republic of Korea
Pathogenic Naegleria fowleri and Acanthamoeba spp., free-living amoebae exist in the natural environment, are causing agents of an acute and lethal primary amoebic meningoencephalitis (PAM) and amoebic keratitis (AK) in humans, respectively. To ascertain the existence of free-living amoebae in Korea, in late August 2015, water samples of eight sites were collected in Korean hydrosphere where water skiing and recreation have been actively performed, and then the non-nutrient agar culture and PCR-based detection technique were carried out. The surface waters were collected and filtered, and then final samples were cultured
