scholarly journals An ITS-based phylogenetic framework for the genus Vorticella : finding the molecular and morphological gaps in a taxonomically difficult group

2013 ◽  
Vol 280 (1771) ◽  
pp. 20131177 ◽  
Author(s):  
Ping Sun ◽  
John C. Clamp ◽  
Dapeng Xu ◽  
Bangqin Huang ◽  
Mann Kyoon Shin ◽  
...  

Vorticella includes more than 100 currently recognized species and represents one of the most taxonomically challenging genera of ciliates. Molecular phylogenetic analysis of Vorticella has been performed so far with only sequences coding for small subunit ribosomal RNA (SSU rRNA); only a few of its species have been investigated using other genetic markers owing to a lack of similar sequences for comparison. Consequently, phylogenetic relationships within the genus remain unclear, and molecular discrimination between morphospecies is often difficult because most regions of the SSU rRNA gene are too highly conserved to be helpful. In this paper, we move molecular systematics for this group of ciliates to the infrageneric level by sequencing additional molecular markers—fast-evolving internal transcribed spacer (ITS) regions—in a broad sample of 66 individual samples of 28 morphospecies of Vorticella collected from Asia, North America and Europe. Our phylogenies all featured two strongly supported, highly divergent, paraphyletic clades (I, II) comprising the morphologically defined genus Vorticella . Three major lineages made up clade I, with a relatively well-resolved branching order in each one. The marked divergence of clade II from clade I confirms that the former should be recognized as a separate taxonomic unit as indicated by SSU rRNA phylogenies. We made the first attempt to elucidate relationships between species in clade II using both morphological and multi-gene approaches, and our data supported a close relationship between some morphospecies of Vorticella and Opisthonecta , indicating that relationships between species in the clade are far more complex than would be expected from their morphology. Different patterns of helix III of ITS2 secondary structure were clearly specific to clades and subclades of Vorticella and, therefore, may prove useful for resolving phylogenetic relationships in other groups of ciliates.

Zootaxa ◽  
2020 ◽  
Vol 4809 (3) ◽  
pp. 547-559
Author(s):  
RONG-JIAO ZHANG ◽  
CONG-LIN ZHAO ◽  
FEI-PENG WU ◽  
WEI-AN DENG

Considerable effort has been devoted to elucidating the phylogenetic relationships of tetrigides. However, there is still no commonly accepted phylogenetic hypothesis. Therefore, the phylogenetic relationships among some subfamilies remain unclear; e.g., Cladonotinae is a controversial group, in which the phylogenetic relationships between genera and the boundaries of some of the included genera are unclear, causing some of the taxa to be difficult to identify. Therefore, an in-depth phylogenetic analysis of Cladonotinae is urgently needed. In this study, a robust phylogenetic framework for the tetrigides was reconstructed based on the combined mitochondrial cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), and nuclear 18S ribosomal RNA (18S rRNA) gene sequences of 25 species belonging to 16 genera of Tetrigoidea from China, which included 13 species from 8 genera of Cladonotinae. Phylogenetic inferences were performed using the combined dataset and Bayesian inference (BI) and Maximum Parsimony (MP) methods, and the phylogenetic tree of Cladonotinae was reconstructed. All inferences based on the results of the present study supported the Cladonotinae subfamily as a polyphyletic group; within the Cladonotinae subfamily, Tetradinodula, and Tuberfemurus were closely related to Tetriginae, while Austrohancockia and Gibbotettix showed a close relationship to the Scelimenidae subfamily. Additionally, a new genus and new species of the Cladonotinae subfamily are described and illustrated: Hainantettix Deng, gen. nov. and Hainantettix strictivertex Deng, sp. nov. 


2021 ◽  
Vol 7 (2) ◽  
pp. 96
Author(s):  
Meng Zhou ◽  
Yu-Cheng Dai ◽  
Josef Vlasák ◽  
Yuan Yuan

Phylogeny and taxonomy of the genus Haploporus were carried out based on a larger number of samples covering a wider geographic range including East Asia, South Asia, Europe, and America, and the species diversity of the genus is updated. Four species, Haploporus bicolor, H. longisporus, H. punctatus and H. srilankensis, are described as new species based on morphology and molecular phylogenetic analyses inferred from the internal transcribed spacer (ITS), the large subunit nuclear ribosomal RNA gene (nLSU), and the small subunit mitochondrial rRNA gene (mtSSU). Haploporus bicolor is characterized by the distinctly different colors between the pore surface and the tubes, small pores measuring 5–7 per mm, and narrow basidiospores measuring 10.5–11.9 × 4.5–5 µm; H. longisporus differs from other species in the genus by its large pores measuring 2–3 per mm, hyphae at dissepiment edge with simple septum, and the long basidiospores (up to 22 µm); H. punctatus is distinguished by its cushion-shaped basidiocarps, wide fusiform cystidioles with a simple septum at the tips, the absence of dendrohyphidia and the cylindrical to slightly allantoid basidiospores measuring 9–10.8 × 3.8–5 µm; H. srilankensis is characterized by its perennial habit, small pores measuring 4–5 per mm, dextrinoid skeletal hyphae, the presence of cystidioles and dendrohyphidia. An identification key to accepted species of Haploporus is provided.


2020 ◽  
Vol 139 ◽  
pp. 15-23
Author(s):  
SRM Jones ◽  
H Ahonen ◽  
J Taskinen

Infections with microsporidian parasites are described in skeletal muscle of burbot Lota lota from Lake Haukivesi, Finland. Infected myocytes contained spores within sporophorous vesicles (SPVs) in contact with host cell cytoplasm, similar to Pleistophora ladogensis in L. lota and smelt Osmerus eperlanus in western Russia and northern Germany. Analysis of small subunit ribosomal RNA (SSU rRNA) gene sequences indicated identity with Myosporidium spraguei in burbot and pike-perch from this lake. The latter is considered a junior synonym of P. ladogensis. Phylogenetic analysis of SSU rRNA sequences resolved the burbot parasite apart from a clade containing the type species P. typicalis, but together with M. merluccius. The parasite is renamed Myosporidium ladogensis (Voronin, 1978) n. comb. Networks of tubular appendages arising from developing meronts and SPVs were associated with degradation of host cell cytoplasm.


2011 ◽  
Vol 61 (4) ◽  
pp. 1001-1010 ◽  
Author(s):  
Ping Sun ◽  
John C. Clamp ◽  
Dapeng Xu ◽  
Yasushi Kusuoka ◽  
Manabu Hori

Little is known about the phylogeny of the family Vorticellidae at the generic level because few comprehensive analyses of molecular phylogenetic relationships between members of this group have, so far, been done. As a result, the phylogenetic positions of some genera that were based originally on morphological analyses remain controversial. In the present study, we performed phylogenetic analyses of vorticellids based on the sequence of the small-subunit (SSU) rRNA gene, including one species of the genus Apocarchesium, for which no sequence has previously been reported. Phylogenetic trees were reconstructed with SSU rRNA gene sequences by using four different methods (Bayesian analysis, maximum-likelihood, neighbour-joining and maximum-parsimony) and had a consistent branching pattern. Members of the genera Vorticella (except V. microstoma) and Carchesium formed a clearly defined, well supported clade that was divergent from the clade comprising members of the genera Pseudovorticella and Epicarchesium, suggesting that the differences in the silverline system (transverse vs reticulate) among vorticellids may be the result of genuine evolutionary divergence. Members of the newly established genus Apocarchesium clustered within the family Vorticellidae basal to the clade containing members of the genera Pseudovorticella and Epicarchesium and were distinct from members of the genus Carchesium, supporting the validity of Apocarchesium as a novel genus. Additional phylogenetic analyses of 21 strains representing seven genera from the families Vorticellidae and Zoothamniidae were performed with single datasets (ITS1–5.8S–ITS2, ITS2 alone) and combined datasets (SSU rRNA+ITS1–5.8S–ITS2, SSU rRNA+ITS2) to explore further the phylogenetic relationship between the three morphologically similar genera Carchesium, Epicarchesium and Apocarchesium, using characteristics not included in previous analyses. The phylogenetic trees reconstructed with combined datasets were more robust and therefore more reliable than those based on single datasets and supported the results of trees based on SSU rRNA sequences.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Joshua X. D. Ang ◽  
Khamisah A. Kadir ◽  
Dayang S. A. Mohamad ◽  
Asmad Matusop ◽  
Paul C. S. Divis ◽  
...  

Abstract Background Plasmodium knowlesi is a significant cause of human malaria in Sarawak, Malaysian Borneo. Only one study has been previously undertaken in Sarawak to identify vectors of P. knowlesi, where Anopheles latens was incriminated as the vector in Kapit, central Sarawak. A study was therefore undertaken to identify malaria vectors in a different location in Sarawak. Methods Mosquitoes found landing on humans and resting on leaves over a 5-day period at two sites in the Lawas District of northern Sarawak were collected and identified. DNA samples extracted from salivary glands of Anopheles mosquitoes were subjected to nested PCR malaria-detection assays. The small subunit ribosomal RNA (SSU rRNA) gene of Plasmodium was sequenced, and the internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of the mosquitoes were sequenced from the Plasmodium-positive samples for phylogenetic analysis. Results Totals of 65 anophelines and 127 culicines were collected. By PCR, 6 An. balabacensis and 5 An. donaldi were found to have single P. knowlesi infections while 3 other An. balabacensis had either single, double or triple infections with P. inui, P. fieldi, P. cynomolgi and P. knowlesi. Phylogenetic analysis of the Plasmodium SSU rRNA gene confirmed 3 An. donaldi and 3 An. balabacensis with single P. knowlesi infections, while 3 other An. balabacensis had two or more Plasmodium species of P. inui, P. knowlesi, P. cynomolgi and some species of Plasmodium that could not be conclusively identified. Phylogenies inferred from the ITS2 and/or cox1 sequences of An. balabacensis and An. donaldi indicate that they are genetically indistinguishable from An. balabacensis and An. donaldi, respectively, found in Sabah, Malaysian Borneo. Conclusions Previously An. latens was identified as the vector for P. knowlesi in Kapit, central Sarawak, Malaysian Borneo, and now An. balabacensis and An. donaldi have been incriminated as vectors for zoonotic malaria in Lawas, northern Sarawak.


Author(s):  
J.-C. Huang ◽  
X.-Y. Li ◽  
Y.-P. Li ◽  
R.-S. Zhang ◽  
D.-B. Chen ◽  
...  

Samia ricini (Wm. Jones) and Samia cynthia (Drury) (Lepidoptera: Saturniidae) have been used as traditional sources of food as well as silk-producing insects. However, the phylogenetic relationship between the two silkworms remains to be addressed. In this study, the mitochondrial cytochrome c oxidase subunit 1 (COI) gene sequences corresponding to DNA barcodes from 13 Samia species were analysed, and a DNA barcode-based phylogenetic framework for these Samia species was provided. Phylogenetic analysis showed that multiple individuals of a species could be clustered together. Our analysis revealed a close relationship among Samia yayukae Paukstadt, Peigler and Paukstadt, Samia abrerai Naumann and Peigler, Samia kohlli Naumann and Peigler, Samia naessigi Naumann and Peigler, Samia naumanni Paukstadt, Peigler and Paukstadt, and Samia kalimantanensis Paukstadt and Paukstadt. The mixed clustering relationship and low Kimura-2-parameter (K2P) genetic distance (0.006) between individuals of S. ricini and Samia canningi (Hutton) indicated that the cultivated silkworm S. ricini was derived from the non-cultivated silkworm S. canningi. The remote phylogenetic relationship and high K2P genetic distance (0.039) indicated that S. ricini and S. cynthia are distinct species, thus providing solid molecular evidence that they had entirely independent origins. The relationships between S. kalimantanensis and S. naumanni and between S. cynthia and Samia wangi Naumann and Peigler, as well as the potential cryptic species within S. abrerai were also discussed. This is the first study to assess the DNA barcodes of the genus Samia, which supplements the knowledge of species identification and provides the first molecular phylogenetic framework for Samia species.


2012 ◽  
Vol 60 (6) ◽  
pp. 526 ◽  
Author(s):  
T. R. Kinge ◽  
A. M. Mih ◽  
M. P. A. Coetzee

Ganoderma is an important genus of the Polyporales in the tropics. Identification of tropical species has mainly been based on morphology, which has led to misidentification. This study aimed to elucidate the diversity and phylogenetic relationships of Ganoderma isolates from different hosts in Cameroon using morphological and molecular techniques. Analyses of basidiocarp morphology and the internal transcribed spacer and mitochondria small subunit were undertaken for 28 isolates from five plant species. The results show that the isolates belong to eight species. Three of the species were identified to species level; of these only G. ryvardense has been previously described from Cameroon while G. cupreum and G. weberianum are new records. The five remaining species did not match with any previously described species and have been designated as Ganoderma with different species affinities.


2018 ◽  
Author(s):  
Jeffrey S. McLean ◽  
Batbileg Bor ◽  
Thao T. To ◽  
Quanhui Liu ◽  
Kristopher A. Kerns ◽  
...  

ABSTRACTRecently, we discovered that a member of the Saccharibacteria/TM7 phylum (strain TM7x) isolated from the human oral cavity, has an ultra-small cell size (200-300nm), a highly reduced genome (705 Kbp) with limited de novo biosynthetic capabilities, and a very novel lifestyle as an obligate epibiont on the surface of another bacterium 1. There has been considerable interest in uncultivated phyla, particularly those that are now classified as the proposed candidate phyla radiation (CPR) reported to include 35 or more phyla and are estimated to make up nearly 15% of the domain Bacteria. Most members of the larger CPR group share genomic properties with Saccharibacteria including reduced genomes (<1Mbp) and lack of biosynthetic capabilities, yet to date, strain TM7x represents the only member of the CPR that has been cultivated and is one of only three CPR routinely detected in the human body. Through small subunit ribosomal RNA (SSU rRNA) gene surveys, members of the Saccharibacteria phylum are reported in many environments as well as within a diversity of host species and have been shown to increase dramatically in human oral and gut diseases. With a single copy of the 16S rRNA gene resolved on a few limited genomes, their absolute abundance is most often underestimated and their potential role in disease pathogenesis is therefore underappreciated. Despite being an obligate parasite dependent on other bacteria, six groups (G1-G6) are recognized using SSU rRNA gene phylogeny in the oral cavity alone. At present, only genomes from the G1 group, which includes related and remarkably syntenic environmental and human oral associated representatives1, have been uncovered to date. In this study we systematically captured the spectrum of known diversity in this phylum by reconstructing completely novel Class level genomes belonging to groups G3, G6 and G5 through cultivation enrichment and/or metagenomic binning from humans and mammalian rumen. Additional genomes for representatives of G1 were also obtained from modern oral plaque and ancient dental calculus. Comparative analysis revealed remarkable divergence in the host-associated members across this phylum. Within the human oral cavity alone, variation in as much as 70% of the genes from nearest oral clade (AAI 50%) as well as wide GC content variation is evident in these newly captured divergent members (G3, G5 and G6) with no environmental relatives. Comparative analyses suggest independent episodes of transmission of these TM7 groups into humans and convergent evolution of several key functions during adaptation within hosts. In addition, we provide evidence from in vivo collected samples that each of these major groups are ultra-small in size and are found attached to larger cells.


Author(s):  
Ran Li ◽  
Wenbao Zhuang ◽  
Congcong Wang ◽  
Hamed El-Serehy ◽  
Saleh A. Al-Farraj ◽  
...  

The morphology and molecular phylogeny of Plagiopyla ovata Kahl, 1931, a poorly known anaerobic ciliate, were investigated based on a population isolated from sand samples collected from the Yellow Sea coast at Qingdao, PR China. Details of the oral ciliature are documented for the first time to our knowledge and an improved species diagnosis is given. The small subunit ribosomal RNA (SSU rRNA) gene was newly sequenced and phylogenetic analyses revealed that P. ovata clusters within the monophyletic family Plagiopylidae. However, evolutionary relationships within both the family Plagiopylidae and the genus Plagiopyla remain obscure owing to undersampling, the lack of sequence data from known species and low nodal support or unstable topologies in gene trees. A key to the identification of the species of the genus Plagiopyla with validly published names is also supplied.


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