scholarly journals Redefinition of the Dinoflagellate Genus Alexandrium Based on Centrodinium: Reinstatement of Gessnerium and Protogonyaulax, and Episemicolon gen. nov. (Gonyaulacales, Dinophyceae)

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Fernando Gómez ◽  
Luis Felipe Artigas

The genus Centrodinium contains oceanic and predominantly tropical species that have received little attention. Three species of Centrodinium were examined using thecal plate dissociation, scanning electron microscopy, and molecular sequences. The apical horn of Centrodinium intermedium and C. eminens is formed by the elongation of the fourth apical plate, and a second apical split into two plates. In C. punctatum two apical plates (2′ and 4′) almost completely encircle the apical pore plate (Po), while the contact with the plate 1′ in the ventral side is much reduced, and the plate 3′ does not reach the Po. Moreover, its left posterior lateral sulcal plate is longer than its right pair, while reversed in the typical Centrodinium spp. The sulcal posterior plate of C. punctatum is located in the left-ventral side below the plates 1′′′ and 2′′′, while the sulcal posterior plate located in the right face below the plates 4′′′ and 5′′′ in the typical Centrodinium spp. Phylogenetic analyses based on the small and large subunit of the rRNA gene showed that Centrodinium spp. and Alexandrium affine/A. gaarderae clustered as a sister clade of the Alexandrium tamarense/catenella/fraterculus groups. The clade of the subgenus Gessnerium, and the clade of the type species of Alexandrium, A. minutum, with four divergent species, clustered in more basal positions. The polyphyly of Alexandrium is solved with the split into four genera: (1) Alexandrium sensu stricto for the species of the clade of A. minutum and four divergent species; (2) the reinstatement of the genus Gessnerium for the species of the clade of A. monilatum; (3) the reinstatement of genus Protogonyaulax for the species of the tamarense/catenella/fraterculus groups, and (4) the new genus Episemicolon gen. nov. for A. affine and A. gaarderae. New combinations in the genera Gessnerium, Protogonyaulax, and Episemicolon are proposed.

2020 ◽  
Vol 59 (2) ◽  
pp. 77-87
Author(s):  
Fernando Gómez ◽  
Luis F. Artigas ◽  
Rebecca J. Gast

The North Sea and the English Channel are regions with a long tradition of plankton studies, where the colony-forming haptophyte Phaeocystis globosa dominates the spring phytoplankton blooms. Among its predators, we investigated an abundant unarmored dinoflagellate (~3000 cells per liter) in the North Sea in May 2019. It has been reported in the literature as Gymnodinium heterostriatum or G. striatissimum, and often identified as Gyrodinium spirale. Phylogenetic analyses using the small-, large subunit- and Internal Transcriber Spacers of the ribosomal RNA (SSU-, LSU-, ITS rRNA) gene sequences indicate that our isolates clustered within the Gyrodinium clade. The new sequences formed a sister group with sequences of the freshwater taxon Gyrodinium helveticum, being one of the infrequent marine-freshwater transitions in the microbial world. This isolate is the first characterized member of a clade of numerous environmental sequences widely distributed from cold to tropical seas. This common and abundant taxon has received several names due to its morphological plasticity (changes of size and shape, often deformed after engulfing prey) and the difficulty in discerning surface striation. We conclude that the priority is for the species name Gymnodinium heterostriatum Kofoid & Swezy 1921, a new name that was proposed for Gymnodinium spirale var. obtusum sensu Dogiel 1906. The species Gyrodinium striatissimum (Hulburt 1957) Gert Hansen & Moestrup 2000 and Gymnodinium lucidum D. Ballantine in Parke & Dixon 1964 (=G. hyalinum M. Lebour 1925) are posterior synonyms. We propose Gyrodinium heterostriatum comb. nov. for Gymnodinium heterostriatum.


Phytotaxa ◽  
2018 ◽  
Vol 351 (1) ◽  
pp. 63
Author(s):  
SHAN SHEN ◽  
TAI-MIN XU ◽  
JASON KARAKEHIAN ◽  
CHANG-LIN ZHAO

A new poroid wood-inhabiting fungal species, Perenniporia bostonensis sp. nov., is proposed based on morphological and molecular characters. The species is characterized by resupinate, cream to buff pore surface; a dimitic hyphal system with skeletal hyphae strongly dextrinoid, unbranched, interwoven and a distinct wide lumen; ovoid to broad ellipsoid, non-truncate, hyaline, distinct thick-walled, smooth, dextrinoid basidiospores, 3.5–4.5 × 3–4 µm. The internal transcribed spacer (ITS) and the large subunit (LSU) regions of nuclear ribosomal RNA gene sequences of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and bayesian inference methods. The phylogenetic analysis based on molecular data of ITS+nLSU sequences showed that P. bostonensis recognized in Perenniporia sensu stricto. The new species formed a monophyletic lineage with a strong support (100% BS, 100% BP, 1.00 BPP) and was closely related to P. bannaensis and P. koreana. Both morphological and molecular characters confirmed the placement of the new species in Perenniporia.


Phytotaxa ◽  
2018 ◽  
Vol 347 (3) ◽  
pp. 235 ◽  
Author(s):  
BIN CAO ◽  
SIQI TAO ◽  
CHENGMING TIAN ◽  
YINGMEI LIANG

The rust species Coleopuccinia sinensis was collected during an investigation of rust fungi in Tibet, a region in south-western China. Through morphological examination, we clarified that C. kunmingensis is a synonym of C. sinensis. Phylogenetic analyses using the combined loci of the internal transcribed spacers (ITS) and the partial large subunit (LSU) rRNA gene revealed that Coleopuccinia should be treated as a separate genus from Gymnosporangium.


2018 ◽  
Vol 66 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Sándor Hornok ◽  
Alexandra Corduneanu ◽  
Jenő Kontschán ◽  
Katinka Bekő ◽  
Krisztina Szőke ◽  
...  

Babesia vesperuginis is the only piroplasm known to infect bats. Unlike most members of the genus Babesia, it is probably transmitted by a soft tick species (i.e. Argas vespertilionis). Recently, two studies have been conducted to clarify the phylogenetic status of this species, and both agreed on placing it into a basal position among Babesia sensu stricto (s.s.). However, several important groups of piroplasms were not included in the already reported phylogenetic trees of B. vesperuginis isolates. Therefore, the aim of the present study was to amplify an approx. 950-bp fragment of the cytochrome c oxidase subunit 1 (cox1) gene of B. vesperuginis from A. vespertilionis specimens, and to compare its sequences with those from other piroplasmid groups in a broader phylogenetic context. Sequence comparisons focusing on either 18S rRNA or cox1 genes, as well as phylogenetic analyses involving separate and concatenated 18S rRNA and cox1 sequences indicate that B. vesperuginis is more closely related to the phylogenetic group of Theileriidae than to Babesia s.s. In particular, B. vesperuginis clustered closest to Cytauxzoon felis and the ‘prototheilerid’ B. conradae. The results of this study highlight that B. vesperuginis is a unique and taxonomically important species, which should be included in future studies aimed at resolving the comprehensive phylogeny of Piroplasmida.


2021 ◽  
Vol 12 ◽  
Author(s):  
Santosh Kumar ◽  
Daizy Bharti ◽  
Shahed Uddin Ahmed Shazib ◽  
Mann Kyoon Shin

Very few studies exist on the description of protozoan ciliates from industrially contaminated sites. In this study, we report a description of a novel hypotrich ciliate isolated from water samples collected from an industrially contaminated outlet in Onsan, Ulsan, South Korea. The oxytrichid ciliate, Histriculus tolerans n. sp., was investigated using live observation and protargol impregnation. The morphology, morphogenesis, and molecular phylogeny inferred from small-subunit (SSU) rRNA gene sequences were studied. The new species is mainly characterized by a cell size of about 70 × 40 μm in vivo, two elongate ellipsoidal macronuclear nodules and one or two micronuclei, adoral zone of about 51% of body length with 32 membranelles on average, about 34 cirri in the right and 24 cirri in the left marginal row, 18 frontoventral transverse cirri, six dorsal kineties including two dorsomarginal rows, and dorsal kinety 1 with 26 bristles. Morphogenesis is similar to that of the type species, i.e., Histriculus histrio, except that oral primordium does not contribute to anlage II of the proter. Phylogenetic analyses, based on small-subunit rRNA gene sequences, consistently place the new species within the family Oxytrichidae, clustering with H. histrio.


2021 ◽  
Vol 7 (11) ◽  
pp. 893
Author(s):  
Asha J. Dissanayake ◽  
Ya-Ya Chen ◽  
Ratchadawan Cheewangkoon ◽  
Jian-Kui Liu

Botryosphaeriales is an important order of diverse fungal pathogens, saprobes, and endophytes distributed worldwide. Recent studies of Botryosphaeriales in China have discovered a broad range of species, some of which have not been formerly described. In this study, 60 saprobic isolates were obtained from decaying woody hosts in southwestern China. The isolates were compared with other species using morphological characteristics, and available DNA sequence data was used to infer phylogenetic analyses based on the internal transcribed spacer (ITS), large subunit rRNA gene (LSU), and translation elongation factor 1-α (tef) loci. Three novel species were illustrated and described as Botryobambusa guizhouensis, Sardiniella elliptica, and Sphaeropsis guizhouensis, which belong to rarely identified genera within Botryosphaeriaceae. Botryobambusa guizhouensis is the second species identified from the respective monotypic genus. The previously known species were identified as Aplosporella hesperidica, Barriopsis tectonae, Botryosphaeria dothidea, Diplodia mutila, Di. neojuniperi, Di. pseudoseriata, Di. sapinea, Di. seriata, Dothiorella sarmentorum, Do. yunnana, Lasiodiplodia pseudotheobromae, Neofusicoccum parvum, Sardiniella celtidis, Sa. guizhouensis, and Sphaeropsis citrigena. The results of this study indicate that numerous species of Botryosphaeriales are yet to be revealed in southwestern China.


MycoKeys ◽  
2021 ◽  
Vol 82 ◽  
pp. 33-56
Author(s):  
Long-Fei Fan ◽  
Renato Lúcio Mendes Alvarenga ◽  
Tatiana Baptista Gibertoni ◽  
Fang Wu ◽  
Yu-Cheng Dai

Samples of species close to Tremella fibulifera from China and Brazil are studied, and T. fibulifera is confirmed as a species complex including nine species. Five known species (T. cheejenii, T. fibulifera s.s., T. “neofibulifera”, T. lloydiae-candidae and T. olens) and four new species (T. australe, T. guangxiensis, T. latispora and T. subfibulifera) in the complex are recognized based on morphological characteristics, molecular evidence, and geographic distribution. Sequences of eight species of the complex were included in the phylogenetic analyses because T. olens lacks molecular data. The phylogenetic analyses were performed by a combined sequence dataset of the internal transcribed spacer (ITS) and the partial nuclear large subunit rDNA (nLSU), and a combined sequence dataset of the ITS, partial nLSU, the small subunit mitochondrial rRNA gene (mtSSU), the translation elongation factor 1-α (TEF1), the largest and second largest subunits of RNA polymerase II (RPB1 and RPB2). The eight species formed eight independent lineages with robust support in phylogenies based on both datasets. Illustrated description of the six species including Tremella fibulifera s.s., T. “neofibulifera” and four new species, and discussions with their related species, are provided. A table of the comparison of the important characteristics of nine species in the T. fibulifera complex and a key to the whitish species in Tremella s.s. are provided.


Botany ◽  
2012 ◽  
Vol 90 (3) ◽  
pp. 205-222 ◽  
Author(s):  
Michael L. MacGillivary ◽  
Irena Kaczmarska

We report on undiscovered genetic and morphological diversity within a diatom taxon known as Paralia longispina and propose three new, extant species of Paralia — Paralia allisonii sp. nov., Paralia crawfordii sp. nov., and Paralia ehrmanii sp. nov. — obtained from subtropical and tropical coasts of the Atlantic and Pacific oceans. Comprehensive examination and hierarchical clustering of frustule characters separated these three species from each other and from P. longispina. Each species possessed one or two unique morphological diagnostic characters. The internal transcribed spacer (ITS) region and a fragment of the small subunit (18S rRNA gene) of nuclear encoded rRNA and a portion of the 5′ end of the large subunit of the ribulose bisophosphate carboxylase (rbcL) gene of the chloroplast genome were related to the morphological groupings of monoclonal isolates of P. allisonii and P. crawfordii. The ITS2 secondary structure of the cultured clones of these two species had four helices. They differed by five hemicompensatory base changes (HCBCs) and substantial changes to the distal end of helix I, the region between helix II and helix III, and nearly all of helix IV. Our results better our understanding of the distribution of subtropical and tropical species of Paralia and have practical implications for the conservation of native microbial florae and for the possibility of ship ballast in human-mediated dispersal of these diatoms.


2008 ◽  
Vol 75 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Meredith D. A. Howard ◽  
G. Jason Smith ◽  
Raphael M. Kudela

ABSTRACT Yessotoxin (YTX) is a globally distributed marine toxin produced by some isolates of the dinoflagellate species Protoceratium reticulatum, Lingulodinium polyedrum, and Gonyaulax spinifera within the order Gonyaulacales. The process of isolating cells and testing each isolate individually for YTX production during toxic blooms are labor intensive, and this impedes our ability to respond quickly to toxic blooms. In this study, we used molecular sequences from the large subunit and internal transcribed spacer genomic regions in the ribosomal operon of known YTX-producing dinoflagellates to determine if genetic differences exist among geographically distinct populations or between toxic and nontoxic isolates within species. In all analyses, all three YTX-producing species fell within the Gonyaulacales order in agreement with morphological taxonomy. Phylogenetic analyses of available rRNA gene sequences indicate that the capacity for YTX production appears to be confined to the order Gonyaulacales. These findings indicate that Gonyaulacoloid dinoflagellate species are the most likely to produce YTX and thus should be prioritized for YTX screening during events. Dinoflagellate species that fall outside of the Gonyaulacales order are unlikely to produce YTX. Although the rRNA operon offers multiple sequence domains to resolve species level diversification within this dinoflagellate order, these domains are not sufficiently variable to provide robust markers for YTX toxicity.


Author(s):  
Aleksey V. Kachalkin ◽  
Dinakhanum A. Abdullabekova ◽  
Elena S. Magomedova ◽  
Andrey M. Yurkov

During an investigation of the yeast communities associated with wild fruit shrubs in Dagestan (Caucasus, Russia), four fermenting ascospore-producing yeast strains were isolated from leaves of the Georgian honeysuckle (Lonicera iberica M. Bieb.) and from soil underneath this plant. Phylogenetic analyses based on concatenated sequences of the ITS region and D1/D2 domains of the large subunit rRNA gene and concatenated sequences of the ribosomal DNA cystron, RPB2 and TEF1 genes showed that the isolated strains represented a new species of the genus Zygotorulaspora. The new species was placed in the basal position to other species of the clade and close to Zygotorulaspora mrakii. Based on the results of phylogenetic analyses and the phenotypic characteristics of the four studied strains, a novel species is described, for which the name Zygotorulaspora dagestanica sp. nov. is proposed. The holotype is KBP Y-4591T, three metabolically inactive cryopreserved isotype cultures are DSM 100088, VKM Y-3060 and VKPM Y-4318. The MycoBank number is MB 838285.


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