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90 • "PROTIST—2016
of pelagic diatom, Skeletonema marinoi JK029 (NC_028615, 38,515 bp) isolated from an interdidal site ofthe Sihwaho (37°18'38.91"N 126°36'16.35"E). Complete mtDNA of each species shows typical bacillariophycean mitochondrial contents, including of35-42 coding sequences (CDS), 2 ribosomal RNA (rRNA), and 25-26 transfer RNA (tRNA) genes. All CDS ofmtDNA aligned with all available diatoms data, including Phaeodactylum tricornutum (NC_016739), Fragilaria acus (NC_013710), and Thalassiosira pseudonana (NC_007405). Based on the saturation test and preliminary sequencing, we suggest mitochondrial markers for diatoms survey on the west coast of Korea.
HORIZONTAL TRANSFER OF A NOVEL SIX-GENE OPERON FROM A BACTERIUM INTO THE PLASTID GENOME OF EUSTIG-MATOPHYTE ALGAE
Yurchenko T.12, Sevcikova T.1, Strnad H.3, Butenko A.1, EliaS M.12
1 - University ofOstrava, Faculty ofScience, Department of Biology and Ecology, Life Science Research Centre, Ostrava, Czech Republic
2 - University ofOstrava, Faculty ofScience, Institute of Environmental Technologies, Ostrava, Czech Republic
3 - Institute ofMolecular Genetics, Czech Academy of Sciences, Prague, Czech Republic tanya.yurchenko@gmail.com
Genes in plastid genomes (plastomes) have been primarily inherited from the cyanobacterial plastid ancestor, but cases of genes acquired by horizontal gene transfer (HGT) have been occassionally reported from plastomes of different algal lineages. Here we report an interesting case of HGT-mediated gene acquisition revealed by sequencing plastomes of the eustigmatophyte algae Monodopsis sp. MarTras21 and Vischeria sp. CAUP 202. While the gene complement of the newly and previously sequenced eustigmatophyte plastomes proved to be highly conserved, those of Monodopsis sp. and Vischeria sp. harbour a cluster of six genes not reported from any plastid genome sequenced so far. All six genes have homologs in various bacteria, where they are usually organized in the same six-gene cluster, i.e. a putative operon. Phylogenetic analyses showed that the cluster from eustigmatophyte plastomes is nested among sequences from the order Cytophagales (phylum Bacteroidetes), with the cluster from Sporocytophaga myxococcoides constituting a robustly resolved sister group to the eustigmatophyte clade. Sequence analyses using different homology-detection tools failed to detect functionally characterized homologs of the protein
encoded by the first gene of the operon, whereas the remaining five proteins could be assigned only to broader enzyme superfamilies. Nevertheless, based on these analyses we speculate that the newly detected operon encodes enzymes of a pathway synthesizing a prenylated aromatic compound, possibly an antimicrobial or other protective substance. To our knowledge, this is the first report of an expansion ofthe metabolic capacity of a plastid mediated by HGT into the plastome.
SPECIES DIVERSITY AND MORPHOLOGY
OF CENTROHELID HELIOZOANS OF SOME
SITES IN EUROPEAN PART OF RUSSIA AND
SOUTH-EAST UKRAINE
Zagumyonnyi D.G.
Voronezh State University, Russia
d.z.agumennyy@mail.ru
The species composition and cytoskeleton morphology of centrohelid heliozoans from different water biotopes ofEuropean Russia and South-East Ukraine have been investigated. 21 species from 6 genera and 3 families have been found. Two forms (Acanthocystis sp. nov. 1. and Acanthocystis sp. nov. 2.) have appeared to be as new species. Following species Acanthocystis turfacea, Heterophrys myriopoda, Polyplacocystis symmetrica, Polyplacocystis coerulea, Acanthocystis dentate have been marked for SouthEast Ukraine for the first time. Also Acanthocystis dentata, Raineriophrys fortesca, Raineriophrys kilianii, Pterocystis foliaea and Pterocystis pulchra have been found for the Central Russia for the first time. Pterocystis pulchra has been revealed for heliozoan fauna of Russia firstly at all. Heterophrys marina has been found in fresh waters of Russia. Polyplacocystis symmetrica has been found in slightly salted biotopes. The morphological descriptions of all studied species have been given. New data on spicule structures of Acanthocystis dentate have been done. Most frequent species was Acanthocystis pectinata. This study was supported by the Russian Scientific Foundation (grant nos. 14-14-00515).
RUBISCO IN NON-PHOTOSYNTHETIC ALGA EUGLENA LONGA: DIVERGENT FEATURES, TRANSCRIPTOMIC ANALYSIS AND REGULATION OF COMPLEX FORMATION Zahonova K.1, Fussy Z.2, Obornik M.234, Elias M.1, Yurchenko V.12
1 - Life Science Research Centre, Department of Biology and Ecology and Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 701 00 Ostrava, Czech Republic
2 - Institute of Parasitology, Biology Centre ASCR, 370 05 Ceske Budejovice, Czech Republic
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3 - University of South Bohemia, Faculty of Science, 370 05 Ceske Budejovice, Czech Republic
4 - Institute ofMicrobiologyASCR, Centrum Agaltech, 379 01 Trebon, Czech Republic kika.z.ahonova@gmail.com
Euglena longa, a close relative of the photosynthetic model alga Euglena gracilis, possesses an enigmatic non-photosynthetic plastid. Its genome has retained a gene for the large subunit of the enzyme RuBisCO (rbcL). Here we provide new data illuminating the putative role of RuBisCO in E. longa. We demonstrated that the E. longa RBCL protein sequence is extremely divergent compared to its homologs from the photosynthetic relatives, suggesting a possible functional shift upon the loss of photosynthesis. Similarly to E. gracilis, E. longa harbors a nuclear gene encoding the small subunit of RuBisCO (RBCS) as a precursor polyprotein comprising multiple RBCS repeats, one of which is highly divergent. Both RBCL and the RBCS proteins are synthesized in E. longa, but their abundance is very low compared to E. gracilis. No RBCS monomers could be detected in E. longa, suggesting that processing of the precursor polyprotein is inefficient in this species. The abundance of RBCS is regulated post-transcriptionally. Indeed, blocking the cytoplasmic translation by cycloheximide has no immediate effect on the RBCS stability in photosynthetically grown E. gracilis, but in E. longa, the protein is rapidly degraded. E. longa appears to lack the chaperone RBCX essential for assembly of a conventional RuBisCO complex. Altogether, our results revealed signatures of evolutionary degradation of RuBisCO in E. longa and suggest that its role in this species may be rather unorthodox.
PROTIST COMMUNITIES IN WATER AND SEDIMENT OF A SEA CUCUMBER FARMING SYSTEM Zhang Q., Tan S., Gong J.
Laboratory of Microbial Ecology and Matter Cycles, Yantai Institute of Coastal Zone Research, Chinese Academy ofScience, Yantai, China jgong@yic.ac.cn
Little is known about the distinctive communities of uncultured protsit within the aquaculture ecosystem. In this work, the planktonic and benthic protist communities in a sea cucumber farming system were simultaneously investigated on three sampling dates. Analyses of SSU rRNA gene libraries of six samples revealed 108 eukaryotic taxonomic units, among which 17.5% were rare. Stramenopiles and Alveolata are predominant groups in both sediment and water samples. Dinophyta, Rhizaria and parasitic Mesomycetozoa were only detected
in water samples. Parasitic Apicomplexa were found frequently from both water and sediment samples. Based on terminal-restriction fragment length polymorphisms, distinct succession and contrasting protist community structure was found among temporal samples and between planktonic and benthic habitats. Redundancy analysis indicated that the temprature, concentration of dissolved phosphate, and N:Si in surface water were the most significant abiotic variables shaping the planktonic communities. This study indicates that temprature and stoichiometric ratios play important roles in driving succession of protist communities, and parasitic protist could be early examed by molecular technologies for the farming pools. This work was supported by projects from NSFC (No. 313018680) and Scientific Development Program of Yantai (No. 2014ZH073).
MAKE PERCISE IDENTIFICAITON USING DNA TAXONOMY TECHNIQUES FOR CLOSELY RELATED EUPLOTES CONGENERS (PROTOZOA, CILIOPHORA) WITH HIGHLY PHENOTYPIC PLASTICITY Zhao Y.1, Yi Z.2, Song W.3
1 - Research Center forEco-Environmental Sciences, Chinese Academy ofSciences, Beijing100085, China
2 - Guangzhou Key Laboratory of Subtropical Biodiversity andBiomonitor, SchoolofLife Science, South China Normal University, Guangzhou 510631, China
3 - Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China yanzhao@rcees.ac.cn
Ciliated protists constitute astounding diversity and play crucial role in different biotopes yet still incompletely characterized microbes. DNA barcoding is promising to address this dilemma. This molecular technique based on COX 1 gene has become a routine method for animal organism identification and taxonomic clarification. This common region also can distinguish ciliates species, but has not displayed universality, and establishing a standardized DNA barcoding system for ciliated protists is still confronted with many difficulties and challenges. Here, we collected the species-rich taxon Euplotes from brackish and fresh waters. In the framework of traditional classification system, the Euplotes spp. with available morphological features can provide a useful template against which to test the accuracy of DNA-based taxonomy. Using >30 samples, we have assessed the most common COX 1 region and the alternative SSU-V4, SSU-V9, LSU-D1/D2, ITS1, ITS2 markers. And SSU-V9, LSU-D1/D2 and ITS1 could distinguish the most
