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Protistology ■ 43
Results from the Tara Oceans metabarcoding study revealed that a significant fraction of the plankton in the sunlit ocean is constituted by diplonemid flagellates, a poorly known group of heterotrophic excavate protists. In an analysis of V9 18S rDNA metabarcodes from planktonic communities collected in 123 globally distributed stations, diplonemids emerge as a highly abundant and extremely diverse group that lacks geographic structuring but displays strong vertical separation. Uniquely among planktonic eukaryotes, taxonomic identification of diplonemids is far from saturation. They are more abundant in polar regions and deeper waters, yet their biological function in the ocean — the largest ecosystem of our biosphere - remains unknown. We are attempting to isolate and culture new marine diplonemids in order to sequence their genomes, analyze their ultrastructure and establish protocols for their genetic manipulation. By this combined approach, we hope to shed more light on these „new kids on the block".
THE SMALL SUBUNIT rRNA GENE SEQUENCE OF THE CHONOTRICH CHILODO-CHONA CARCINI JANKOWSKI, 2007 CONFIRMS CHONOTRICHS AS A DYSTERIID-DERIVED CLADE (PHYLLOPHARYNGEA, CILIOPHORA) Lynn D.H.
Department of Integrative Biology, University of Guelph, Guelph, ON Canada N1G 2W1 lynn@zoology.ubc.ca
The chonotrichs are sessile ciliated protozoa ectosymbiotic on the body parts of a variety of crustaceans. They have long been considered a separate group because their sessile habit has resulted in the evolution of a very divergent body form and reproductive strategy compared to free-living ciliates. In the mid-20th Century, the free-living dysteriid cyrtophorian ciliates were proposed as a potential sister clade because the chonotrich bud or daughter cell showed similarities during division morphogenesis (i.e. ontogeny) to these free-living dysteriids. A single small subunit (SSU) rRNA gene sequence is available for the chonotrich Isochona sp. However, its authenticity has been questioned in the recent literature, and the placement of this sequence within the dysteriid clade has added to this controversy. In this report, the SSUrRNA gene sequence of the chonotrich Chilodochona carcini ectosymbiotic on the green crab Carcinus maenas is provided. Topology testing of the SSUrRNA gene phylogeny constructed by Bayesian Inference robustly supports the sister-group relationship of Isochona sp. and C. carcini, the monophyly of
these two chonotrichs, and the divergence of the chonotrich clade within the dysteriid clade.
MAPPING THE HIDDEN DIVERSITY OF FREE LIVING FRESH WATER CILIATES FROM DELHI REGION, INDIA Makhija S.1, Abraham J.S.1, Somasundaram S.1, Toteja R.1, Gupta R.2
1 - Acharya Narendra Dev College, University ofDelhi, Delhi, India
2 - Maitreyi College, University ofDelhi, Delhi, India seemamakhija@andc.du.ac.in
India, with 2.4% of the world's area, has over 8% of the world's total biodiversity, making it one ofthe 12 mega diversity countries in the world. Despite this richness, the data concerning ciliate diversity from India is rather scarce. We at University of Delhi have been involved in the morphological and molecular taxonomy of ciliates from freshwater bodies namely from Okhla Bird Sanctuary, Sanjay Lake, Pond at Rajghat in Delhi region. A large number of species from different classes have been observed from these water samples namely from genus Tetmemena, Stylonychia, Laurentiella, Euplotes, Aspidisca, Paraurostyla, Gastrostyla, Pseudourostyla, Urostyla, Oxytricha and Uroleptus from class Spirotrichea; Blepharisma, Spirostomum and Stentor from class Heterotrichea; Paramecium, Frontonia, Vorticella and Cyclidium from class Oligohymenophorea; Litonotus, Dileptus, Didinium and Lacrymaria from class Litostomatea; Colpoda from class Colpodea; Chilodonella from class Phyllopharyngea; Loxodes from class Karyorelectia; and Coleps from class Prostomatea have been identified by live cell observations, protargol staining, silver staining and morphometric measurements. In the present study, we describe in detail few species from the subclass Stichotrichia and Hypotrichea. There is difficulty in understanding the phylogenetic relationship between different species of these group based solely on morphological markers. Therefore, we are trying to look into both morphological and multiple molecular markers like SSU- rRNA, ITS 1, ITS2 , hsp70 and histone genes and we could depict morphological and molecular congruence in the species from subclass Stichotrichia and Hypotrichea.
GLOBAL SHIFTS IN GENE EXPRESSION PROFILES ACCOMPANIED WITH ENVIRONMENTAL CHANGES IN CNIDARIAN-DINOFLAGELLATE ENDOSYMBIOSIS Maruyama S.1, Aihara Y.2, Yamaguchi T.3, Yama-guchi K.4, Shigenobu S.4, Takahashi H.3, Kawata M.1, Ueno N.3, Minagawa J.2
