Научная статья на тему 'First marine photosynthetic testate amoeba containing the chromatophore: Paulinella longichromatophora'

First marine photosynthetic testate amoeba containing the chromatophore: Paulinella longichromatophora Текст научной статьи по специальности «Биологические науки»

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Текст научной работы на тему «First marine photosynthetic testate amoeba containing the chromatophore: Paulinella longichromatophora»

34 • "PROTIST—2016

might represent new deeply-branching lineages of microbial eukaryotes, currently without any cultured representatives or morphological information.

THE PLASTID GENOMES OF THE CRYPTO-MONAD ALGAE REVEAL LINEAGE-SPECIFIC GENE LOSS

Kim J.I.1. Yi G.2, Yoon H.S.3, Shin W.1

1 - Department of Biology, Chungnam National University, Daejeon, Korea

2 - Department of Computer Science, Gangneung-Wonju National University, Wonju, Korea

3 - Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea

shinw@cnu.ac.kr

Cryptophytes are an enigmatic group of photo-synthetic unicellular eukaryotes with plastids derived from red alga through secondary endosymbiosis that contains four different genomes (host nuclear. mitochondrial. plastid, and nucleomorph) in a cell. They are comprised of brown-, red-, or blue/ green photosynthetic species. as well as colorless nonphotosynthetic species. Although its complex evolutionary history, the origins of the host and endosymbiont components in cryptophyte algae are poorly understood. Here, we report a comparative analysis of plastid genomes from six cryptophyte genera. Three newly determiend cryptomonads plastid genomes of Chroomonas, Cryptomonas, and Storeatula share a number of features including gene arrangement and gene content with previously reported ones of Rhodomonas, Teleaulax and Guil-lardia. The plastid genomes of cryptomonads reveal lineage-specific gene loss and intron insertion in eight significant gene syntenic positions. The chlL/ chlN/chlB genes, which is the light-independent (dark active) protochlorophyllide oxidoreductase (LIPOR), show the evolutionary changes across the cryptomonad lineages. We will discuss phylogenetic relationships of the red-derived lineages using 93 plastid genes showing a strong monophyletic group of the cryptophytes and haptophytes.

A NEW SOIL CILIATE, BIROJIMIA SOYAEN-SIS NOV. SPEC. (CILIOPHORA: UROSTYLI-DA) FROM SOUTH KOREA Kim Kang-San1, Jung Jae-Ho2, Min Gi-Sik3

1 - Department ofBiological Sciences, Inha University, 100Inha-ro, Nam-gu, Incheon 22212

2 - Department of Biology, Gangneung-Wonju National University, Jukheon-gil, Gangneung-si, Gangwon-do, 25457, South Korea

3 - Department ofBiological Sciences, Inha University, 100Inha-ro, Nam-gu, Incheon 22212, South Korea mingisik@inha.ac.kr

A new soil urostylid ciliate, Birojimia soyaensis nov. spec., was discovered from Soya Island, Incheon, South Korea. It is described the species based on live and stained specimen observation, and 18S ribosomal RNA gene sequence analyses. Birojimia soyaensis nov. spec. is characterized by the following features: body slender elongate and somewhat twisted; 170—200 ^m * 40—50 ^m body size in vivo; contractile vacuole located at middle of left cell margin; cortical granules present; 37—48 adoral membranelles; 3 frontal and 2 frontoterminal cirri present; III/2 and buccal cirrus present; midventral pairs only; pretransverse ventral and transverse cirri present; 1 left and 4 right marginal rows, including 3 compound rows; 5 complete dorsal kineties with additional 3 shortened kineties which are anteriorly of compound rows; 8—11 caudal cirri; 53—69 macronuclear nodules; and 2 or 3 micronuclei. Birojimia soyaensis nov. spec. is similar to B. terricola, but is distinguished by cortical granules (present vs. absent), number of caudal cirri (8—11 vs. 2—7) and number of dorsal bristle rows (8 vs. 6, on average). Birojimia muscorum is separated from B. terricola and B. soyaensis n. sp. by midventral row present (vs. absent, midventral pairs only) which is an important key of the Bakuellidae. Furthermore, in phylogenetic tree, Birojimia soyaensis has widely distance from the bakuellids. Thus, we agree with Berger (2006) that the new genus needs to establish for B. muscorum. Phylogenetic tree suggests this new species is the most closely related to the genus Hemicycliostyla.

FIRST MARINE PHOTOSYNTHETIC TESTATE AMOEBA CONTAINING THE CHRO-MATOPHORE: PAULINELLA LONGICHRO-MATOPHORA Kim S.1, Park M.G.2

1 - Department of Oceanography, Pukyong National University, Busan, Republic of Korea

2 - Department ofOceanography, Chonnam National University, Gwangju, Republic of Korea mpark@chonnam.ac.kr

Of 10 formally described species in the genus, all species are marine heterotrophic species, except for one freshwater species, Paulinella chromatophora which is the sole species to have plastids termed the "chromatophores" of a Synechococcus/Prochloro-coccus-like cyanobacterial origin. Here, we report the first marine phototrophic species, Paulinella longichromatophora sp. nov., using light and electron microscopy and molecular data. This new species contains two blue-green U-shaped plastids reaching up to 40 ^m in length. Further, the new Paulinella species is characterized by having five oral scales

Protistology ■ 35

surrounding the pseudostomal aperture. All trees generated using three nuclear rDNA datasets (18S rDNA, 28S rDNA, and the concatenated 18S + 28S rDNA) demonstrated that three photo-synthetic Paulinella species congruently formed a monophyletic group with robust bootstrap and Bayesian supports (>99% RAxML and 1.0 Baye-sian support), but their relationships remained unresolved within the clade in all trees. The P. longichromatophora, nevertheless, clustered consistently together with Paulinella strain FK01, but with very poor supported. Phylogenetic analyses inferred from plastid-encoded 16S rDNA and the concatenated dataset of plastid 16S+23S rDNA demonstrated that chromatophores of all photosynthetic Paulinella species formed a mono-phyly and fell within cyanobacteria clade with a close relationship to a-cyanobacterial clade containing Prochlorococcus and Synechococcus species with very robust supports of 100% bootstraps and 1.0 Bayesian posterior probabilities. Additionally, phylogenetic analyses of nuclear 18S rDNA and plastid 16S rDNA showed divergent evolution within the photosynthetic Paulinella population after a single acquisition of the chromatophore. After the single acquisition of the chromatophore, ancestral photosynthetic Paulinella appears to diverge into at least two distinct clades, one containing marine P. longichromatophora and freshwater Paulinella strain FK01, the other P. chromatophora CCAC 0185.

PREY SPECIFICITY AND MOLECULAR PHY-LOGENY OF THE THECATE MIXOTROPHIC DINOFLAGELLATE FRAGILIDIUM MEXI-CANUM

Kim S.1, Park M.G.2

1 - Department of Oceanography, Pukyong National University, Busan, Republic of Korea

2 - Department ofOceanography, Chonnam National University, Gwangju, Republic of Korea sunjukim75@gmail.com

Feeding mechanism and prey specificity of the mixotrophic thecate dinoflagellate Fragilidium mexicanum (strain Fm-LOHABE01) were examined using the culture isolated from Masan Bay, Korea in 2011 during summer blooms of the toxic dinoflagellate Alexandrium pacificum. We also used novel 18S and 28S rDNA sequences for F. mexicanum to explore inter-species relationships within the genus Fragilidium and to examine its phylogenetic relationships with morphologically similar species (Alexandrium, Goniodoma, and Pyrophacus). F. mexicanum (strain Fm-LOHABE01) fed on species belonging to three dinoflagellate genera (i.e. Alexandrium, Ceratium, and Heterocapsa) when

separately offered a variety of prey including dino-flagellates, raphidophytes, cryptophytes, and a ci-liate. In addition, F. mexicanum displayed different levels of specificity for species of Alexandrium. While F. mexicanum consistently fed on A. fundyense and A. pacificum, feeding on A. affine was observed only once. F. mexicanum ingested prey by direct engulfment through the sulcus, after capturing the prey by a tow filament. Phylogenetic analyses of 18S and 28S rDNA datasets demonstrated that Fragilidium sequences formed a monophyletic group with high statistical supports and diverged into four distinct clades. The first clade consisted of seven F. cf. duplocampanaeforme strains, F. subglobosum from New Zealand, and an unidentified Fragilidium sp. from Florida, USA. The second clade branched as a single sequence for F. subglobosum from Denmark and formed a sister lineage to F. cf. duplocampanaeforme, with weak statistical support. The third clade included Fragilidium sp. EUSK D from Angola, as well as Korean strains of F. mexicanum and F. fissile, and was very strongly supported. The last clade contained the five most divergent sequences of F. subglobosum strains. Further, phylogenetic analyses revealed that the genera Fragilidium and Pyrophacus were sister to a clade that included Alexandrium and Goniodoma. Pyrophacus was a sister to a clade containing members of the genus Fragilidium.

TWO ENIGMATIC GENERA ARE ONE? COMPARISON OF BELONOCYSTISMARINA KLI-MOV, ZLATOGURSKY, 2016 WITH LUFFISPHAERA SPP Klimov V.I.

St.Petersburg State University, Faculty of Biology, Department of Invertebrate Zoology JoeRex40@ya.ru

Belonocystis Rainer, 1968 and Luffisphaera Belcher and Swale, 1975 are enigmatic genera, which currently lack supergroup affiliation. The genus Belonocystis was studied mainly on the light-microscopy level, while the genus Luffisphaera was studied only with electron microscopy. Recently provided ultrastructural data on Belonocystis gave an opportunity to compare these taxa using one and the same method. This analysis discovered many similarities in the organization of the cell structure as well as in morphology of the coverings. It was clearly shown that surface structures of Belonocystis represent not a solid capsule, but giant scales, which are similar to those of Luffisphaera. Comparison of the scales has revealed that some Belonocystis species were similar to Luffisphaera species more than inside the genus. Each scale of B. marina was

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