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on non-nutrient agar medium with inactivated E. coli and subjected to PCR with various primer pairs (amplify mainly the 18S-small ribosomal RNA). Free-living amoebae were intensively detected by PCR in two collection regions (Yeoju and Yangpeong city around Southern Han-Liver). PCR products obtained from water samples of Yeoju and Yangpeong city were subjected to gene sequencing. The similarity of 18S-rRNA sequences were compared with various reference amoebae in GeneBank, and they showed 86-99% homology with N. gruberi, N. philippinensis, N. clarki, Acanthamoeba polyphaga and Vermamoeba vermiformis. A Korean isolate (confirmed by PCR as A. polyphaga) was isolated from Yeoju sample and have been subcultured in Nelson’s and PYG liquid medium with 10% FBS at 30 °C incubator. In the in vitro cytotoxicity test, Korean isolate (tentative A. polyphaga) showed high cytotoxicity as much as reference amoebae, A. polyphaga and A. castellanii. This study will be useful, in the further study, for the detailed seasonal detection of free-living amoebae from Korean hydrosphere.
MORPHOLOGICAL AND GENETIC DIVERSITY OF OPISTHOSPORIDIA: NEW APHELID PARAPHELIDIUM TRIBONEMAE GEN. ET SP. NOV
Karpov S.A.12, Tcvetkova V.S.2, Mamkaeva M.A.2, Torruella G.3, Timpano H.3, Moreira D.3, Lopez-Garcia P.3
1 - Zoological Institute, Russian Academy ofSciences, Universitetskaya nab. 1, St. Petersburg 199034, Russian Federation
2 - St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russian Federation
3 - Unite dEcologie, Systematique etEvolution, UMR CNRS 8079, Universite Paris-Sud, 91405 Orsay cedex, France
sakarpov4@gmail.com
Aphelids are a poorly known group of parasitoids of algae that have raised considerable interest due to their pivotal phylogenetic position. Together with Cryptomycota and the highly derived Microspo-ridia, they have recently re-classified as the Opistho-sporidia, which constitute the sister group to the fungi within the Holomycota. Despite their huge diversity, as revealed by molecular environmental studies, and their phylogenetic interest, only three genera have been described (Aphelidium, Amoeboaphelidium, and Pseudaphelidium), from which 18S rRNA gene sequences exist only for Amoeboaphelidium and Aphelidium species. Here, we present the molecular phylogeny, life cycle and ultrastructure of new freshwater aphelid, which is a new genus and species
Paraphelidium tribonemae. Molecular phylogenetic analysis of 18S rRNA gene sequences ofthis parasite indicates that P. tribonemae defines a distinct cluster which is only distantly related to Amoebaphelidium and Aphelidium, what confirms the wide genetic diversity ofthe aphelids. P. tribonemae has amoeboid opisthokont zoospores which are twice smaller than morphologically similar zoospores of Aphelidium aff. melosirae. Nonetheless, although the morphology of Paraphelidium species is generally similar to that of Aphelidium representatives, molecular phylogenetic analyses unambiguously show, that the two clades of strains are distantly related and must define two distinct genera.
We thank RFBR grant No. 15-29-02734 for financial support, and for cultivation of strains and access to the EM facilities the Center for Culturing Collection of Microorganisms and the Research Resource Center for Molecular and Cell Technologies (RRC MCT) of Research park of St. Petersburg State University correspondingly.
AN EVOLUTIONARY TRANSITION OF CHLOROPLAST DEGRADATION IN EU-GLENOIDS: HETEROTROPHIC DIGESTION TO SECONDARY PLASTID SENESCENCE Kashiyama Y.12, Kawahara J.1, Maruyama M.1, Kayama M.1, Nakazawa M.3, Tanifuji G.4, Yoko-yama A.5, Ishikawa T.6, Tamiaki H.2, Suzaki T.7
1 - Fukui University of Technology
2 - Ritsumeikan University
3 - Osaka Prefecture University
4 - National Museum of Nature and Science
5 - National Institute for Environmental Studies
6 - Shimane University
7 - Kobe University chiro@fukui-ut.ac.jp
Establishments of regulatory mechanisms for the integrated endosymbiont must have been key steps in organelle acquisitions, where both endosymbiont and host processes cooperated to evolve new functions. Specifically important for the chloroplast is to establish regulatory mechanisms for chlorophyll-related metabolisms since the phototoxicity of chlorophyll would cause fatal damages. In particular, regulated degradation of chloroplasts or chloroplast dismantlement is critical not only for recycling nutrients but also for disposing the phototoxic chlorophylls safely. Unlike land plants, little has been understood for algae on chloroplast dismantlement and associated chlorophyll catabolism. We previously reported that the phototrophic euglenoid accumulates 132,173-cyclopheophorbide enols (CPEs) within their cells; CPEs are non-phototoxic catabolites
