Ultrastructural and molecular delineation of the Chytridiaceae (Chytridiales)

2005 ◽  
Vol 83 (12) ◽  
pp. 1561-1573 ◽  
Author(s):  
Peter M. Letcher ◽  
Martha J. Powell ◽  
James G. Chambers ◽  
Joyce E. Longcore ◽  
Perry F. Churchill ◽  
...  

The Chytridiomycota is in need of taxonomic revision, especially the largest order, the Chytridiales. We analyzed 25 isolates in, or allied to, the Chytridium clade of this order. Isolates were selected based on one or more of the following criteria: (i) having a large subunit molecular sequence similar to that of the type of the genus Chytriomyces, (ii) having specific zoospore morphology, and (iii) currently classified as a species in the genus Chytriomyces . We examined ultrastructural characters and partial sequences of large subunit and small subunit rDNA and generated a phylogenetic hypothesis using maximum parsimony and Bayesian analyses. The sequence analyses strongly supported the Chytridiaceae, Phlyctochytrium, and Chytriomyces angularis clades, and each clade had a specific zoospore type. Developmental morphology of the thallus did not mirror the DNA-based phylogeny. Based on the results of phylogenetic analyses of sequences and ultrastructural characters, we emend the Chytridiaceae by including exogenous and polycentric development and define the family on the basis of a single zoospore type. Species identified as being in the genus Chytriomyces occur in several separate, well-supported clades along with species currently classified in seven other genera ( Asterophlyctis , Entophlyctis , Obelidium , Physocladia , Podochytrium , Rhizoclosmatium , and Siphonaria ), indicating that Chytriomyces as currently defined is polyphyletic.

2021 ◽  
Vol 12 ◽  
Author(s):  
Boo Seong Jeon ◽  
Myung Gil Park

The phylum Perkinsozoa is known as an exclusively parasitic group within alveolates and is widely distributed in various aquatic environments from marine to freshwater environments. Nonetheless, their morphology, life cycle, the identity of the host, and physiological characteristics remain still poorly understood. During intensive sampling along the west coast of Korea in October and November 2017, a new parasitoid, which shares several characteristics with the extant families Perkinsidae and Parviluciferaceae, was discovered and three strains of the new parasitoid were successfully established in cultures. Cross-infection experiments showed that among the examined planktonic groups, only dinoflagellates were susceptible to the new parasitoid, with infections observed in species belonging to eight genera. Even though the new parasitoid shared many morphological and developmental characteristics with other Perkinsozoan parasites, it differed from them by its densely packed trophocyte structure without a large vacuole or hyaline material during the growth stage. These characteristics are common among Parviluciferaceae members. Furthermore, through palintomic extracellular sporogenesis, it produced characteristic interconnected sporocytes resembling a string of beads. Phylogenetic analyses based on the small subunit and large subunit ribosomal DNA sequences revealed that the new parasitoid was distantly related to the family Parviluciferaceae and was more closely related to the families Perkinsidae and Xcellidae. Morphological, ultrastructural, and molecular data on the new parasitoid raised the need to erect a new family, i.e., Pararosariidae, within the phylum Perkinsozoa with Pararosarium dinoexitiosum gen. et sp. nov. as the type species. The isolation and establishment in culture of the new parasitoid outside the family Parviluciferaceae in the present study would contribute to the better understanding of the diversity of Perkinsozoan parasites and provide useful material for comparisons to other parasite species in the further study.


2013 ◽  
Vol 48 (1) ◽  
pp. 89-103 ◽  
Author(s):  
Janusz Błaszkowski ◽  
Gerard Chwat

An updated morphology of spores of <em>Septoglomus deserticola</em>, an arbuscular mycorrhizal fungus of the phylum Glomeromycota, is presented based on the original description of the species, only one other its definition recently published and spores produced in pot cultures inoculated with the rhizosphere soil and root fragments of an unrecognized grass colonizing maritime sand dunes of the Hicacos Peninsula, Cuba. Phylogenetic analyses of sequences of the large subunit (LSU) nrDNA region of the Cuban fungus confirmed its affinity with <em>S. deserticola </em>deposited in the International Bank for the Glomeromycota (BEG) and indicated that its closest relatives are <em>S. fuscum </em>and <em>S. xanthium</em>. Phylogenetic analyses of sequences of the small subunit (SSU) nrDNA confirmed the Cuban fungus x <em>S. fuscum </em>x <em>S. xanthium </em>relationship revealed in analyses of the LSU sequences and thereby suggested the Cuban <em>Septoglomus </em>is <em>S. deserticola</em>. However, it was impossible to prove directly the identity of the Cuban fungus and <em>S. deserticola </em>from BEG based on SSU sequences due to the lack of <em>S. deserticola </em>SSU sequences in public databases. In addition, phylogenetic analyses of LSU and SSU sequences confirmed the uniqueness of the recently erected genus <em>Corymbiglomus </em>with the type species <em>C. corymbiforme </em>(formerly <em>Glomus corymbiforme</em>) in the family Diversisporaceae and proved that its LSU sequences group in a clade with LSU sequences of <em>G. globiferum </em>and <em>G. tortuosum</em>. Consequently, the two latter species were transferred to <em>Corymbiglomus </em>and named <em>C. globiferum </em>comb. nov. and <em>C. tortuosum </em>comb. nov., and the definitions of the family Diversisporaceae and the genus <em>Diversispora </em>were emended.


2013 ◽  
Vol 87 (2) ◽  
pp. 211-216 ◽  
Author(s):  
Bernard L. Cohen ◽  
Maria Aleksandra Bitner

We present here the first report based on phylogenetic analyses of small subunit (SSU/18S) and large subunit (LSU/28S) ribosomal DNA (rDNA) sequences from a wider-than-token sample of rhynchonellide articulate brachiopods, with data from 11 of ∼20 extant genera (12 species) belonging to all four extant superfamilies. Data exploration by network and saturation analyses shows that the molecular sequence data are free from major aberrations and are suitable for phylogenetic reconstruction despite the presence of large deletions in four SSU rDNA sequences. Although molecular sequence analyses cannot directly illuminate the systematics of fossils, the independent, genealogical evidence and phylogenetic inferences about extant forms that they make possible are highly relevant to paleontological systematics because they highlight the limitations of evolutionary inference from morphology. Parsimony, distance, maximum likelihood (no clock) and Bayesian (relaxed-clock) analyses all find a tree topology that disagrees strongly with the existing superfamily classification. All tested phylogenetic reconstructions agree that the taxa analyzed fall into three clades designated A1, A2, and B that reflect two major divergence events. The relaxed-clock analysis indicates that clades A and B diverged in the Paleozoic, while clades A1 and A2 reflect Permo-Triassic (and later) events. Morphological homoplasy and possible gene co-option are suggested as the main sources for the discord between the morpho-classification, the results of cladistic analyses of morphology, and the relationships reconstructed from molecular sequences. The origin, function and evolutionary implications of the deletion-bearing rhynchonellide SSU rDNA sequences are briefly discussed in relation to pseudogenes and concerted evolution in the rDNA genomic region.


2021 ◽  
Vol 12 ◽  
Author(s):  
Zhe Wang ◽  
Tong Wu ◽  
Borong Lu ◽  
Yong Chi ◽  
Xue Zhang ◽  
...  

During an investigation on freshwater peritrichs, a new colonial sessilid ciliate, Campanella sinica n. sp., was isolated from aquatic plants in an artificial freshwater pond in Qingdao, China. Specimen observations of this species were performed both in vivo and using silver staining. C. sinica n. sp. is characterized by the appearance of the mature colony, which is up to 2 cm high and contains more than 1,000 zooids, the asymmetric horn-shaped zooids, strongly everted and multi-layered peristomial lip, the slightly convex peristomial disc, and the well-developed haplokinety and polykinety, which make more than four circuits of the peristome before descending into the infundibulum. The small subunit ribosomal DNA (SSU rDNA), 5.8s rDNA and its flank internal transcribed spacers (ITS1-5.8s rDNA-ITS2), and large subunit ribosomal DNA (LSU rDNA) are sequenced and used for phylogenetic analyses which reveal that the family Epistylididae Kahl, 1933 is non-monophyletic whereas the genus Campanella is monophyletic and nests within the basal clade of the sessilids. The integrative results support the assertion that the genus Campanella represents a separate lineage from other epistylidids, suggesting a further revision of the family Epistylididae is needed. We revise Campanella including the transfer into this genus of a taxon formerly assigned to Epistylis, which we raise to species rank, i.e., Campanella ovata (Nenninger, 1948) n. grad. &amp; n. comb. (original combination Epistylis purneri f. ovataNenninger, 1948). In addition, we provide a key to the identification of the species of Campanella.


2019 ◽  
Vol 187 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Borong Lu ◽  
Lifang Li ◽  
Xiaozhong Hu ◽  
Daode Ji ◽  
Khaled A S Al-Rasheid ◽  
...  

Abstract The classification of loricate peritrich ciliates is difficult because of an accumulation of several taxonomic problems. In the present work, three poorly described vaginicolids, Pyxicola pusilla, Cothurnia ceramicola and Vaginicola tincta, were isolated from the surface of two freshwater/marine algae in China. In our study, the ciliature of Pyxicola and Vaginicola is revealed for the first time, demonstrating the taxonomic value of infundibular polykineties. The small subunit rDNA, ITS1-5.8S rDNA-ITS2 region and large subunit rDNA of the above species were sequenced for the first time. Phylogenetic analyses based on these genes indicated that Pyxicola and Cothurnia are closely related. The present study suggested that the loricate species probably represent a distinct lineage in peritrich evolution and both genera Cothurnia and Thuricola are monophyletic. Pyxicola pusilla, Cothurnia ceramicola and Vaginicola tincta are recircumscribed.


Zootaxa ◽  
2018 ◽  
Vol 4526 (4) ◽  
pp. 576
Author(s):  
WEN-JIA WU ◽  
CHUN-LING XU ◽  
DONG-WEI WANG ◽  
HUI XIE

A new species, Eudorylaimus piceae n. sp., extracted from rhizosphere soil of Picea crassifolia from Inner Mongolia, China was identified. The new species is characterized by these combined characters: body length of 1.03–1.27 mm; lip region distinctly offset; odontostyle 20–22 μm and 1.1–1.4 times the lip region diameter in length; odontophore 1.1–1.2 times the odontostyle length; basal expansion of pharynx occupying 42%–50.5% of the total neck length; genital system didelphic-amphidelphic; vulva transverse; vagina extending inwards 32%–43%; V value averaging more than 60; pars refringens vaginae with two trapezoidal sclerotizations and pars distalis vaginae weakly sclerotized; prerectum 72–107 μm long, 2.3–3.3 times the anal body diameter, and rectum 1–1.6 times the anal body diameter in length; tail conoid and bent ventrally, c’ value 1.5–1.8 and males unknown. Phylogenetic analyses based on sequences of 18S small subunit rDNA and the D2-D3 expansion region of 28S rDNA are presented. 


2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Gao ◽  
Chen Shao ◽  
Qiuyue Tang ◽  
Jingbao Li

The morphology and morphogenesis of Pseudosincirra longicirrata nov. gen. and nov. comb., isolated from southern China, were investigated with living observation and protargol staining. Our population is similar to the original population in living characteristics and ciliary patterns. The main determinable morphogenetic features of P. longicirrata nov. comb. are the presence of five frontoventral-transverse cirral anlagen (FVT-anlagen) and a dorsomarginal kinety anlage. According to the origin of FVT-anlagen IV and V in proter, it can be determined that P. longicirrata nov. comb. possesses two frontoventral rows and one right marginal row. Hence, a new genus, Pseudosincirra nov. gen., is proposed, and the diagnosis of P. longicirrata nov. comb. is improved. The new genus is diagnosed as follows: adoral zone of membranelles and undulating membranes is in a Gonostomum pattern; there are three enlarged frontal cirri, one buccal cirrus, and one parabuccal cirrus; postperistomial cirrus and transverse cirri are lacking; there are two more or less long frontoventral rows and one right and two or more left marginal rows; cirri within all rows very widely spaced; dorsal kinety pattern is of Urosomoida type, that is, three dorsal kineties and one dorsomarginal kinety; and caudal cirri are present. Phylogenetic analyses based on the small subunit ribosomal (SSU rDNA) sequence data indicate that P. longicirrata nov. comb. clusters with Deviata and Perisincirra. It is considered that Pseudosincirra nov. gen. and Perisincirra paucicirrata should be assigned to the family Deviatidae; fine cirri, and cirri within all rows being relatively widely spaced, should be considered as plesiomorphies of Deviatidae; and Deviatidae is closely related to Dorsomarginalia or Strongylidium–Hemiamphisiella–Pseudouroleptus.


Phytotaxa ◽  
2021 ◽  
Vol 483 (2) ◽  
pp. 117-128
Author(s):  
NAKARIN SUWANNARACH ◽  
JATURONG KUMLA ◽  
SAISAMORN LUMYONG

A new endophytic ascomycete, described herein as Spegazzinia camelliae, was isolated from leaves of Camellia sinensis var. assamica collected from Nan Province, Thailand. This species is characterized by basauxic conidiophores and dark brown to blackish brown α and β conidia. It can be distinguished from previously described Spegazzinia species by the spine length of the α conidia and the size of the β conidia. Multi-gene phylogenetic analyses of the small subunit (SSU), large subunit (LSU) and internal transcribed spacers (ITS) of the nuclear ribosomal DNA (rDNA) and the translation elongation factor 1-alpha (tef1) genes also support S. camelliae is a distinct new species within Spegazzinia. A full description, color photographs, illustrations and a phylogenetic tree showing the position of S. camelliae are provided.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yi-Fan Cao ◽  
Hui-Xia Chen ◽  
Yang Li ◽  
Dang-Wei Zhou ◽  
Shi-Long Chen ◽  
...  

Abstract Background The Tibetan antelope Pantholops hodgsonii (Abel) (Artiodactyla: Bovidae) is an endangered species of mammal endemic to the Qinghai-Tibetan Plateau. Parasites and parasitic diseases are considered to be important threats in the conservation of the Tibetan antelope. However, our present knowledge of the composition of the parasites of the Tibetan antelope remains limited. Methods Large numbers of nematode parasites were collected from a dead Tibetan antelope. The morphology of these nematode specimens was observed using light and scanning electron microscopy. The nuclear and mitochondrial DNA sequences, i.e. small subunit ribosomal DNA (18S), large subunit ribosomal DNA (28S), internal transcribed spacer (ITS) and cytochrome c oxidase subunit 1 (cox1), were amplified and sequenced for molecular identification. Moreover, phylogenetic analyses were performed using maximum likelihood (ML) inference based on 28S and 18S + 28S + cox1 sequence data, respectively, in order to clarify the systematic status of these nematodes. Results Integrated morphological and genetic evidence reveals these nematode specimens to be a new species of pinworm Skrjabinema longicaudatum (Oxyurida: Oxyuridae). There was no intraspecific nucleotide variation between different individuals of S. longicaudatum n. sp. in the partial 18S, 28S, ITS and cox1 sequences. However, a high level of nucleotide divergence was revealed between the new species and its congeners in 28S (8.36%) and ITS (20.3–23.7%) regions, respectively. Molecular phylogenetic results suggest that the genus Skrjabinema should belong to the subfamily Oxyurinae (Oxyuroidea: Oxyuridae), instead of the subfamily Syphaciidae or Skrjabinemiinae in the traditional classification, as it formed a sister relationship to the genus Oxyuris. Conclusions A new species of pinworm Skrjabinema longicaudatum n. sp. (Oxyurida: Oxyuridae) is described. Skrjabinema longicaudatum n. sp. represents the first species of Oxyurida (pinworm) and the fourth nematode species reported from the Tibetan antelope. Our results contribute to the knowledge of the species diversity of parasites from the Tibetan antelope, and clarify the systematic position of the genus Skrjabinema.


1993 ◽  
Vol 71 (9) ◽  
pp. 1249-1265 ◽  
Author(s):  
G. Hausner ◽  
J. Reid ◽  
G. R. Klassen

Phylogenetic analysis of partial rDNA sequences suggests that Ophiostoma should remain the sole genus of the Ophiostomataceae, and this should be the sole family within the Ophiostomatales, whereas Ceratocystis s.s. would be best disposed within the Microascales. Although morphological criteria suggest that the genus Ophiostoma is heterogeneous, analysis of partial small subunit rDNA sequence data shows that Ophiostoma (excluding O. roraimense) represents a monophyletic taxon. Analysis of a partial large subunit rDNA data set, which included sequences from 55 species assignable to Ophiostoma, failed to support the strict subdivision of the genus based on either ascospore characters or the nature of the anamorph. Key words: Ceratocystis, Microascus, Ophiostoma, partial rDNA sequences, phylogeny.


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