scholarly journals Telonema antarcticum sp. nov., a common marine phagotrophic flagellate

2005 ◽  
Vol 55 (6) ◽  
pp. 2595-2604 ◽  
Author(s):  
Dag Klaveness ◽  
Kamran Shalchian-Tabrizi ◽  
Helge Abildhauge Thomsen ◽  
Wenche Eikrem ◽  
Kjetill S. Jakobsen
Keyword(s):  
Molecular Phylogeny ◽  
Small Subunit ◽  
Food Vacuole ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Small Subunit Rrna ◽  
Ssu Rrna Gene ◽  
Structural Identity ◽  
Food Particles ◽  
Ssu Rrna Gene Sequence

Telonema is a widely distributed group of phagotrophic flagellates with two known members. In this study, the structural identity and molecular phylogeny of Telonema antarcticum was investigated and a valid description is proposed. Molecular phylogeny was studied using small-subunit rRNA (SSU rRNA) gene sequences. The pear-shaped cell had two subequal flagella that emerged laterally on the truncated antapical tail. One flagellum had tripartite hairs. The cell was naked, but had subsurface vesicles containing angular paracrystalline bodies of an unknown nature. A unique complex cytoskeletal structure, the subcortical lamina, was found to be an important functional and taxonomic feature of the genus. Telonema has an antero-ventral depression where food particles are ingested and then transferred to a conspicuous anterior food vacuole. The molecular phylogeny inferred from the SSU rRNA gene sequence suggested that Telonema represents an isolated and deep branch among the tubulocristate protists.

Taxonomy, morphology and molecular systematics of three oligotrich ciliates, including a description of Apostrombidium parakielum spec. nov. (Ciliophora, Oligotrichia)

2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1179-1191 ◽  
Author(s):  
Wen Song ◽  
Jiamei Li ◽  
Weiwei Liu ◽  
Jiamei Jiang ◽  
Khaled A. S. Al- Rasheid ◽  
...  
Keyword(s):  
Sequence Data ◽  
Novel Species ◽  
Small Subunit ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
The Novel ◽  
Small Subunit Rrna ◽  
Ssu Rrna Gene ◽  
Single Clade ◽  
Ssu Rrna Gene Sequence

Three oligotrich ciliates, Apostrombidium parakielum spec. nov., Novistrombidium apsheronicum (Alekperov & Asadullayeva, 1997) Agatha, 2003 and Novistrombidium testaceum (Anigstein, 1914) Song & Bradbury, 1998 were collected from the coastal waters of China and their morphology and small-subunit rRNA (SSU rRNA) gene sequences were studied. The novel species can be recognized by the combination of its obconical body shape, 14–16 anterior and 6–8 ventral membranelles, somatic kinety in three parts and conspicuously long dorsal cilia. Based on the data obtained for this novel species, an improved diagnosis of the genus Apostrombidium is supplied. Descriptions of the population of N. apsheronicum and N. testaceum collected in this study are also provided and compared with the existing descriptions. In addition, the phylogenetic positions of these three species are inferred from their SSU rRNA gene sequence data. The results indicate that the genus Apostrombidium, the systematics of which has not previously been discussed using molecular information, clusters with Varistrombidium kielum and Omegastrombidium elegans, whereas N. testaceum and N. apsheronicum form a single clade.

Molecular characterization and phylogenetic relationships among microsporidian isolates infecting silkworm, Bombyx mori using small subunit rRNA (SSU-rRNA) gene sequence analysis

2012 ◽  
Vol 57 (4) ◽  
Author(s):  
B. Nath ◽  
S. Gupta ◽  
A. Bajpai
Keyword(s):  
Sequence Analysis ◽  
Gene Sequence ◽  
Small Subunit ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Rrna Gene Sequence ◽  
Small Subunit Rrna ◽  
Ssu Rrna Gene ◽  
Gene Sequence Analysis ◽  
Ssu Rrna Gene Sequence

AbstractThe life cycle, spore morphology, pathogenicity, tissue specificity, mode of transmission and small subunit rRNA (SSU-rRNA) gene sequence analysis of the five new microsporidian isolates viz., NIWB-11bp, NIWB-12n, NIWB-13md, NIWB-14b and NIWB-15mb identified from the silkworm, Bombyx mori have been studied along with type species, NIK-1s_mys. The life cycle of the microsporidians identified exhibited the sequential developmental cycles that are similar to the general developmental cycle of the genus, Nosema. The spores showed considerable variations in their shape, length and width. The pathogenicity observed was dose-dependent and differed from each of the microsporidian isolates; the NIWB-15mb was found to be more virulent than other isolates. All of the microsporidians were found to infect most of the tissues examined and showed gonadal infection and transovarial transmission in the infected silkworms. SSU-rRNA sequence based phylogenetic tree placed NIWB-14b, NIWB-12n and NIWB-11bp in a separate branch along with other Nosema species and Nosema bombycis; while NIWB-15mb and NIWB-13md together formed another cluster along with other Nosema species. NIK-1s_mys revealed a signature sequence similar to standard type species, N. bombycis, indicating that NIK-1s_mys is similar to N. bombycis. Based on phylogenetic relationships, branch length information based on genetic distance and nucleotide differences, we conclude that the microsporidian isolates identified are distinctly different from the other known species and belonging to the genus, Nosema. This SSU-rRNA gene sequence analysis method is found to be more useful approach in detecting different and closely related microsporidians of this economically important domestic insect.

scholarly journals phyloFlash: Rapid Small-Subunit rRNA Profiling and Targeted Assembly from Metagenomes

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Harald R. Gruber-Vodicka ◽  
Brandon K. B. Seah ◽  
Elmar Pruesse
Keyword(s):  
High Throughput ◽  
Small Subunit ◽  
General Purpose ◽  
Reference Database ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Small Subunit Rrna ◽  
Ssu Rrna Gene ◽  
Domains Of Life ◽  
Environmental Microbes

ABSTRACT The small-subunit rRNA (SSU rRNA) gene is the key marker in molecular ecology for all domains of life, but it is largely absent from metagenome-assembled genomes that often are the only resource available for environmental microbes. Here, we present phyloFlash, a pipeline to overcome this gap with rapid, SSU rRNA-centered taxonomic classification, targeted assembly, and graph-based binning of full metagenomic assemblies. We show that a cleanup of artifacts is pivotal even with a curated reference database. With such a filtered database, the general-purpose mapper BBmap extracts SSU rRNA reads five times faster than the rRNA-specialized tool SortMeRNA with similar sensitivity and higher selectivity on simulated metagenomes. Reference-based targeted assemblers yielded either highly fragmented assemblies or high levels of chimerism, so we employ the general-purpose genomic assembler SPAdes. Our optimized implementation is independent of reference database composition and has satisfactory levels of chimera formation. phyloFlash quickly processes Illumina (meta)genomic data, is straightforward to use, even as part of high-throughput quality control, and has user-friendly output reports. The software is available at https://github.com/HRGV/phyloFlash (GPL3 license) and is documented with an online manual. IMPORTANCE To track organisms across all domains of life, the SSU rRNA gene is the gold standard. Many environmental microbes are known only from high-throughput sequence data, but the SSU rRNA gene, the key to visualization by molecular probes and link to existing literature, is often missing from metagenome-assembled genomes (MAGs). The easy-to-use phyloFlash software suite tackles this gap with rapid, SSU rRNA-centered taxonomic classification, targeted assembly, and graph-based linking to MAGs. Starting from a cleaned reference database, phyloFlash profiles the taxonomic diversity and assembles the sorted SSU rRNA reads. The phyloFlash design is domain agnostic and covers eukaryotes, archaea, and bacteria alike. phyloFlash also provides utilities to visualize multisample comparisons and to integrate the recovered SSU rRNAs in a metagenomics workflow by linking them to MAGs using assembly graph parsing.

Redescriptions of three trachelocercid ciliates (Protista, Ciliophora, Karyorelictea), with notes on their phylogeny based on small subunit rRNA gene sequences

2013 ◽  
Vol 63 (Pt_9) ◽  
pp. 3506-3514 ◽  
Author(s):  
Ying Yan ◽  
Yuan Xu ◽  
Zhenzhen Yi ◽  
Alan Warren
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Small Subunit ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Small Subunit Rrna ◽  
Small Subunit Rrna Gene ◽  
Ssu Rrna Gene Sequence ◽  
First Time

Three trachelocercid ciliates, Kovalevaia sulcata (Kovaleva, 1966) Foissner, 1997, Trachelocerca sagitta (Müller, 1786) Ehrenberg, 1840 and Trachelocerca ditis (Wright, 1982) Foissner, 1996, isolated from two coastal habitats at Qingdao, China, were investigated using live observation and silver impregnation methods. Data on their infraciliature and morphology are supplied. The small subunit rRNA (SSU rRNA) genes of K. sulcata and Trachelocerca sagitta were sequenced for the first time. Phylogenetic analyses based on SSU rRNA gene sequence data indicate that both organisms, and the previously sequenced Trachelocerca ditis, are located within the trachelocercid assemblage and that K. sulcata is sister to an unidentified taxon forming a clade that is basal to the core trachelocercids.

scholarly journals Phylogenetic position of Multicilia marina and the evolution of Amoebozoa

2006 ◽  
Vol 56 (6) ◽  
pp. 1449-1458 ◽  
Author(s):  
Sergey I. Nikolaev ◽  
Cédric Berney ◽  
Nikolai B. Petrov ◽  
Alexandre P. Mylnikov ◽  
José F. Fahrni ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Strong Support ◽  
Molecular Data ◽  
Small Subunit ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Ssu Rrna Gene ◽  
Slime Moulds ◽  
Ssu Rrna Gene Sequence

Recent molecular phylogenetic studies have led to the erection of the phylum Amoebozoa, uniting naked and testate lobose amoebae, the mycetozoan slime moulds and amitochondriate amoeboid protists (Archamoebae). Molecular data together with ultrastructural evidence have suggested a close relationship between Mycetozoa and Archamoebae, classified together in the Conosea, which was named after the cone of microtubules that, when present, is characteristic of their kinetids. However, the relationships of conoseans to other amoebozoans remain unclear. Here, we obtained the complete small-subunit (SSU) rRNA gene sequence (2746 bp) of the enigmatic, multiflagellated protist Multicilia marina, which has formerly been classified either in a distinct phylum, Multiflagellata, or among lobose amoebae. Our study clearly shows that Multicilia marina belongs to the Amoebozoa. Phylogenetic analyses including 60 amoebozoan SSU rRNA gene sequences revealed that Multicilia marina branches at the base of the Conosea, together with another flagellated amoebozoan, Phalansterium solitarium, as well as with Gephyramoeba sp., Filamoeba nolandi and two unidentified amoebae. This is the first report showing strong support for a clade containing all flagellated amoebozoans and we discuss the position of the root of the phylum Amoebozoa in the light of this result.

scholarly journals Sequence Variation in the Small-Subunit rRNA Gene of Plasmodium malariae and Prevalence of Isolates with the Variant Sequence in Sichuan, China

1998 ◽  
Vol 36 (11) ◽  
pp. 3378-3381 ◽  
Author(s):  
Qing Liu ◽  
Shenghua Zhu ◽  
Sahoko Mizuno ◽  
Masatsugu Kimura ◽  
Peina Liu ◽  
...  
Keyword(s):  
Southern China ◽  
Plasmodium Malariae ◽  
Small Subunit ◽  
Diagnostic Methods ◽  
Rrna Gene ◽  
Variant Form ◽  
Target Sequence ◽  
Ssu Rrna ◽  
Small Subunit Rrna ◽  
Ssu Rrna Gene

By two PCR-based diagnostic methods, Plasmodium malariae infections have been rediscovered at two foci in the Sichuan province of China, a region where no cases of P. malariae have been officially reported for the last 2 decades. In addition, a variant form of P. malariae which has a deletion of 19 bp and seven substitutions of base pairs in the target sequence of the small-subunit (SSU) rRNA gene was detected with high frequency. Alignment analysis of Plasmodium sp. SSU rRNA gene sequences revealed that the 5′ region of the variant sequence is identical to that of P. vivax or P. knowlesi and its 3′ region is identical to that of P. malariae. The same sequence variations were also found inP. malariae isolates collected along the Thai-Myanmar border, suggesting a wide distribution of this variant form from southern China to Southeast Asia.

Morphological Redescriptions and Molecular Phylogeny of Three Stentor Species (Ciliophora: Heterotrichea: Stentoridae) from Korea

Zootaxa ◽  
2020 ◽  
Vol 4732 (3) ◽  
pp. 435-452
Author(s):  
MD ABU TAHER ◽  
AHMED SALAHUDDIN KABIR ◽  
SHAHED UDDIN AHMED SHAZIB ◽  
MIN SEOK KIM ◽  
MANN KYOON SHIN
Keyword(s):  
Gene Sequence ◽  
Small Subunit ◽  
Rrna Gene ◽  
Sequence Information ◽  
Ssu Rrna ◽  
Rrna Gene Sequence ◽  
Cortical Granules ◽  
Ssu Rrna Gene ◽  
Ssu Rrna Gene Sequence

The morphologies of the three freshwater stentorid ciliates in Korea, Stentor coeruleus (Pallas, 1766); Stentor muelleri Ehrenberg, 1831, and Stentor tartari Murthy & Bai, 1974, were investigated based on live observations and protargol impregnation. The Korean population of S. tartari exhibits the following characteristics: body size 200–355 × 85–135 µm in vivo, 62–106 somatic kineties, 8–13 peristomial kineties, 110–180 adoral membranelles, mostly two macronuclear nodules and 5–18 micronuclei, reddish and colorless cortical granules and the presence of symbiotic algae. We identified S. tartari based on unique characteristics compared to close congeners. Korean populations of S. coeruleus and S. muelleri are congruent with previously described populations in most aspects of their morphologies. Here, for the first time, we report molecular gene sequence information for S. tartari. Small subunit (SSU) rRNA gene sequence-based phylogeny indicates that S. tartari, which has multiple macronuclei, forms a monophyletic group with other Stentor species having a single macronucleus. Our findings based on morphology and SSU rRNA gene sequence information corroborate the hypothesis that the elongated macronucleus evolved from the compact single or multi macronucleus state. 

scholarly journals Morphological and phylogenetic studies on three members of the genus Pseudochilodonopsis (Ciliophora, Cyrtophoria) isolated from brackish waters in China, including a novel species, Pseudochilodonopsis quadrivacuolata sp. nov.

2015 ◽  
Vol 65 (Pt_12) ◽  
pp. 4323-4334 ◽  
Author(s):  
Zhishuai Qu ◽  
Hongbo Pan ◽  
Khaled A. S. Al-Rasheid ◽  
Xiaozhong Hu ◽  
Shan Gao
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Small Subunit ◽  
Dorsal Side ◽  
Rrna Gene ◽  
Ssu Rrna ◽  
Ssu Rrna Gene ◽  
Ssu Rrna Gene Sequence

Three cyrtophorian ciliates isolated from brackish biotopes in China, Pseudochilodonopsis quadrivacuolata sp. nov., Pseudochilodonopsis fluviatilis Foissner, 1988 and Pseudochilodonopsis mutabilis Foissner, 1981, were investigated using living observation and protargol-staining methods. P. quadrivacuolata sp. nov. can be characterized as follows: cell size 50–70 × 30–40 μm in vivo; body oval with posterior end rounded; four tetragonally positioned contractile vacuoles; 12–15 nematodesmal rods; five right and six left somatic kineties; terminal fragment positioned apically on dorsal side, consisting of 11–14 basal bodies; four or five fragments in preoral kinety. P. fluviatilis and P. mutabilis were generally consistent with previous descriptions. In addition, a brief revision and a key to Pseudochilodonopsis are presented. The small-subunit (SSU) rRNA gene was also sequenced to support the identification of these species. Phylogenetic analyses based on molecular data indicate that the genera Pseudochilodonopsis and Chilodonella are closely related and both are well outlined; that is, all known congeners for which SSU rRNA gene sequence data are available group together, forming the core part of the family Chilodonellidae.

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