Phylogenetic relationships between Toxoplasma and Sarcocystis deduced from a comparison of 18S rDNA sequences

SUMMARYThe current taxonomy of parasites in the genus Sarcocystis is largely based on morphological characteristics as well as on host specificity and life-cycle structure. Recently, phylogenetic analyses of partial ribosomal RNA (rRNA) sequences provided support for paraphyly of Sarcocystis. We have tested the validity of this hypothesis by sequencing the complete 18S rRNA genes of Sarcocystis arieticanis, Sarcocystis gigantea and Sarcocystis tenella and comparing them with gene sequences derived from other taxa of the phylum Apicomplexa. The results obtained from this study do not reject the hypothesis of monophyly of Sarcocystis species, although the bootstrap data were inconclusive for some species.

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Phylogeny of hymenolepidids (Cestoda: Cyclophyllidea) from mammals: sequences of 18S rRNA and COI genes confirm major clades revealed by the 28S rRNA analyses

Journal of Helminthology ◽

10.1017/s0022149x21000110 ◽

2021 ◽

Vol 95 ◽

Author(s):

B. Neov ◽

G.P. Vasileva ◽

G. Radoslavov ◽

P. Hristov ◽

D.T.J. Littlewood ◽

...

Keyword(s):

Ribosomal Rna ◽

18S Rrna ◽

Phylogenetic Analyses ◽

The Other ◽

Rrna Genes ◽

Host Switching ◽

28S Rrna ◽

Mitochondrial Cytochrome ◽

Rapid Radiation ◽

18S Rrna Genes

Abstract The aim of the study is to test a hypothesis for the phylogenetic relationships among mammalian hymenolepidid tapeworms, based on partial (D1–D3) nuclear 28S ribosomal RNA (rRNA) genes, by estimating new molecular phylogenies for the group based on partial mitochondrial cytochrome c oxidase I (COI) and nuclear 18S rRNA genes, as well as a combined analysis using all three genes. New sequences of COI and 18S rRNA genes were obtained for Coronacanthus integrus, C. magnihamatus, C. omissus, C. vassilevi, Ditestolepis diaphana, Lineolepis scutigera, Spasskylepis ovaluteri, Staphylocystis tiara, S. furcata, S. uncinata, Vaucherilepis trichophorus and Neoskrjabinolepis sp. The phylogenetic analyses confirmed the major clades identified by Haukisalmi et al. (Zoologica Scripta 39: 631–641, 2010): Ditestolepis clade, Hymenolepis clade, Rodentolepis clade and Arostrilepis clade. While the Ditestolepis clade is associated with soricids, the structure of the other three clades suggests multiple evolutionary events of host switching between shrews and rodents. Two of the present analyses (18S rRNA and COI genes) show that the basal relationships of the four mammalian clades are branching at the same polytomy with several hymenolepidids from birds (both terrestrial and aquatic). This may indicate a rapid radiation of the group, with multiple events of colonizations of mammalian hosts by avian parasites.

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A new species of the genus Sarsamphiascus Huys, 2009 (Copepoda: Harpacticoida: Miraciidae) from a sublittoral zone of Hawaii

PeerJ ◽

10.7717/peerj.8506 ◽

2020 ◽

Vol 8 ◽

pp. e8506

Author(s):

Jisu Yeom ◽

Wonchoel Lee

Keyword(s):

New Species ◽

Ribosomal Rna ◽

Morphological Characteristics ◽

Distinct Species ◽

Rrna Genes ◽

Sublittoral Zone ◽

Species Type ◽

18S Rrna Genes ◽

Sandy Sediments ◽

A New Species

A new species of Sarsamphiascus Huys, 2009 was collected from sandy sediments of Hawaii at 12 –18 m depth. While the new species, Sarsamphiascus hawaiiensis sp. nov., is morphologically most closely related to S. kawamurai (Ueda & Nagai, 2005), the two species can be distinguished by the combination of the following morphological characteristics: elongated segments of the antennule in the new species, type of outer setae of the P5 exopod (bare in S. kawamurai), position of the inner seta of the P5 exopod in both sexes (more proximal in S. kawamurai), length and type of the setae of female P6 (shorter and bare in S. kawamurai). This is the first species of Sarsamphiascus from Hawaii to be discovered. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (mtCOI) and nuclear 18S ribosomal RNA (18S rRNA) genes confirmed that S. hawaiiensis and S. kawamurai are distinct species.

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Three Redescriptions in Tintinnopsis (Protista ：Ciliophora: Tintinnina) from Coastal Waters of China, with Cytology and Phylogenetic Analyses Based on Ribosomal RNA Genes

10.21203/rs.3.rs-27632/v1 ◽

2020 ◽

Author(s):

Yang Bai ◽

Rui Wang ◽

Wen Song ◽

Lifang Li ◽

Luciana F. Santoferrara ◽

...

Keyword(s):

Ribosomal Rna ◽

Coastal Waters ◽

Phylogenetic Analyses ◽

Rrna Genes ◽

Rrna Gene ◽

Closely Related Species ◽

Molecular Information ◽

Ciliary Tuft ◽

Rna Genes ◽

Rrna Sequences

Abstract Background: The taxonomy of tintinnine ciliates is vastly unresolved because it has traditionally been based on the lorica (a secreted shell) and it has only recently incorporated cytological and molecular information. Tintinnopsis, the most speciose tintinnine genus, is also the most problematic: it is known to be non-monophyletic, but it cannot be revised until more of its species are studied with modern methods.Results: Here, T. hemispiralis Yin, 1956, T. kiaochowensis Yin, 1956, and T. uruguayensis Balech, 1948, from coastal waters of China, were studied. Lorica and cell features were morphometrically investigated in living and protargol-stained specimens, and sequences of three ribosomal RNA (rRNA) genes were phylogenetically analyzed. The three species show a complex ciliary pattern (with ventral, dorsal, and posterior kineties and right, left, and lateral ciliary fields), but differ in lorica morphology, details of the somatic ciliature and rRNA gene sequences. Tintinnopsis hemispiralis is further distinguished by a ciliary tuft (a ribbon of very long cilia originating from the middle portion of the ventral kinety and extending out of the lorica) and multiple macronuclear nodules. Both T. kiaochowensis and T. uruguayensis have two macronuclear nodules, but differ in the number of somatic kineties and the position of the posterior kinety. Two neotypes are fixed for T. hemispiralis and T. kiaochowensis to stabilize the species names objectively, mainly because of the previous unavailability of type materials. By phylogenetic analysis and comparison with closely-related species, we infer that the ciliary tuft and details such as the commencement of the rightmost kinety in the lateral ciliary field are synapomorphies that may help clarify the systematics of Tintinnopsis-like taxa.Conclusion: The redescriptions of three poorly known Tintinnopsis species, namely T. hemispiralis, T. kiaochowensis, and T. uruguayensis firstly revealed their ciliary pattern and rRNA sequences. This study expands knowledge and database of tintinnines and helps in identifying potential synapomorphies for future taxonomic rearrangements.

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Characterization, Comparative Analysis and Phylogenetic Implications of Mitogenomes of Fulgoridae (Hemiptera: Fulgoromorpha)

Genes ◽

10.3390/genes12081185 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1185

Author(s):

Wenqian Wang ◽

Huan Zhang ◽

Jérôme Constant ◽

Charles R. Bartlett ◽

Daozheng Qin

Keyword(s):

Control Region ◽

Ribosomal Rna ◽

Phylogenetic Analyses ◽

Start Codon ◽

Rrna Genes ◽

Rich Region ◽

Protein Coding ◽

Phylogenetic Implications ◽

Rna Genes ◽

Unpaired Base

The complete mitogenomes of nine fulgorid species were sequenced and annotated to explore their mitogenome diversity and the phylogenetics of Fulgoridae. All species are from China and belong to five genera: Dichoptera Spinola, 1839 (Dichoptera sp.); Neoalcathous Wang and Huang, 1989 (Neoalcathous huangshanana Wang and Huang, 1989); Limois Stål, 1863 (Limois sp.); Penthicodes Blanchard, 1840 (Penthicodes atomaria (Weber, 1801), Penthicodes caja (Walker, 1851), Penthicodes variegata (Guérin-Méneville, 1829)); Pyrops Spinola, 1839 (Pyrops clavatus (Westwood, 1839), Pyrops lathburii (Kirby, 1818), Pyrops spinolae (Westwood, 1842)). The nine mitogenomes were 15,803 to 16,510 bp in length with 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and a control region (A + T-rich region). Combined with previously reported fulgorid mitogenomes, all PCGs initiate with either the standard start codon of ATN or the nonstandard GTG. The TAA codon was used for termination more often than the TAG codon and the incomplete T codon. The nad1 and nad4 genes varied in length within the same genus. A high percentage of F residues were found in the nad4 and nad5 genes of all fulgorid mitogenomes. The DHU stem of trnV was absent in the mitogenomes of all fulgorids sequenced except Dichoptera sp. Moreover, in most fulgorid mitogenomes, the trnL2, trnR, and trnT genes had an unpaired base in the aminoacyl stem and trnS1 had an unpaired base in the anticodon stem. The similar tandem repeat regions of the control region were found in the same genus. Phylogenetic analyses were conducted based on 13 PCGs and two rRNA genes from 53 species of Fulgoroidea and seven outgroups. The Bayesian inference and maximum likelihood trees had a similar topological structure. The major results show that Fulgoroidea was divided into two groups: Delphacidae and ((Achilidae + (Lophopidae + (Issidae + (Flatidae + Ricaniidae)))) + Fulgoridae). Furthermore, the monophyly of Fulgoridae was robustly supported, and Aphaeninae was divided into Aphaenini and Pyropsini, which includes Neoalcathous, Pyrops, Datua Schmidt, 1911, and Saiva Distant, 1906. The genus Limois is recovered in the Aphaeninae, and the Limoisini needs further confirmation; Dichoptera sp. was the earliest branch in the Fulgoridae.

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Unexplored diversity of microscopic myxomycetes: evidence from environmental DNA

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1621 ◽

2019 ◽

Vol 152 (3) ◽

pp. 499-506 ◽

Cited By ~ 2

Author(s):

Oleg N. Shchepin ◽

Martin Schnittler ◽

Nikki H.A. Dagamac ◽

Dmitry V. Leontyev ◽

Yuri K. Novozhilov

Keyword(s):

New Species ◽

18S Rdna ◽

Sequence Similarity ◽

Phylogenetic Analyses ◽

Environmental Dna ◽

Full Length ◽

Detection Techniques ◽

Rdna Sequences ◽

18S Rdna Sequences ◽

Environmental Sequences

Background and aims – Recent studies showed the position of two slime mould species with microscopic sporocarps, Echinosteliopsis oligospora and Echinostelium bisporum, within the class Myxomycetes. These minute species are seldom seen in studies based on detection of sporocarps and can easily be confused with protosteloid amoebozoans.Methods – We searched all published ePCR data sets that targeted myxomycete 18S rDNA for the presence of environmental sequences similar to E. oligospora and Echinosteliales in traditional circumscription, and performed phylogenetic analyses that included short environmental sequences and full-length 18S rDNA sequences representing all the major groups of myxomycetes.Key results – We report 19 unique sequences which are closely related to E. bisporum or E. oligospora based on sequence similarity (73.1–95.2% similarity) and which form well-supported monophyletic clades with these species in phylogenetic analyses. They may represent new species that are not yet described. Our phylogeny based on full-length 18S rDNA sequences further confirms the position of E. bisporum and E. oligospora within myxomycetes and the paraphyly of the order Echinosteliales in its traditional circumscription.Conclusions – Our results show that ePCR-based studies can reveal myxomycete taxa that often escape detection by traditional approaches, including potentially new species, and thus provide valuable new data on diversity and ecology of myxomycetes. As such, strategies for studying myxomycetes biodiversity should be revised, focusing also on molecular detection techniques in addition to the sporocarp-based ones.

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Three redescriptions in Tintinnopsis (Protista: Ciliophora: Tintinnina) from coastal waters of China, with cytology and phylogenetic analyses based on ribosomal RNA genes

BMC Microbiology ◽

10.1186/s12866-020-02057-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Yang Bai ◽

Rui Wang ◽

Wen Song ◽

Lifang Li ◽

Luciana F. Santoferrara ◽

...

Keyword(s):

Ribosomal Rna ◽

Coastal Waters ◽

Phylogenetic Analyses ◽

Rrna Gene ◽

Middle Portion ◽

Closely Related Species ◽

Molecular Information ◽

Ciliary Tuft ◽

Rna Genes ◽

Rrna Sequences

Abstract Background The taxonomy of tintinnine ciliates is vastly unresolved because it has traditionally been based on the lorica (a secreted shell) and it has only recently incorporated cytological and molecular information. Tintinnopsis, the most speciose tintinnine genus, is also the most problematic: it is known to be non-monophyletic, but it cannot be revised until more of its species are studied with modern methods. Results Here, T. hemispiralis Yin, 1956, T. kiaochowensis Yin, 1956, and T. uruguayensis Balech, 1948, from coastal waters of China, were studied. Lorica and cell features were morphometrically investigated in living and protargol-stained specimens, and sequences of three ribosomal RNA (rRNA) loci were phylogenetically analyzed. The three species show a complex ciliary pattern (with ventral, dorsal, and posterior kineties and right, left, and lateral ciliary fields), but differ in lorica morphology, details of the somatic ciliature and rRNA gene sequences. Tintinnopsis hemispiralis is further distinguished by a ciliary tuft (a ribbon of very long cilia originated from the middle portion of the ventral kinety and extending out of the lorica) and multiple macronuclear nodules. Both T. kiaochowensis and T. uruguayensis have two macronuclear nodules, but differ in the number of somatic kineties and the position of the posterior kinety. Two neotypes are fixed for T. hemispiralis and T. kiaochowensis to stabilize the species names objectively, mainly because of the previous unavailability of type materials. By phylogenetic analysis and comparison with closely-related species, we infer that the ciliary tuft and details such as the commencement of the rightmost kinety in the lateral ciliary field are synapomorphies that may help clarify the systematics of Tintinnopsis-like taxa. Conclusion The redescriptions of three poorly known Tintinnopsis species, namely T. hemispiralis, T. kiaochowensis, and T. uruguayensis firstly revealed their ciliary patterns and rRNA sequences. This study expands knowledge and database of tintinnines and helps in identifying potential synapomorphies for future taxonomic rearrangements.

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Characterization of SSU and LSU rRNA genes of threeTrypanosoma (Herpetosoma) grosiisolates maintained in Mongolian jirds

Parasitology ◽

10.1017/s0031182004006493 ◽

2004 ◽

Vol 130 (2) ◽

pp. 157-167 ◽

Cited By ~ 16

Author(s):

H. SATO ◽

A. OSANAI ◽

H. KAMIYA ◽

Y. OBARA ◽

W. JIANG ◽

...

Keyword(s):

Ribosomal Rna ◽

Geographical Origin ◽

Large Subunit ◽

Meriones Unguiculatus ◽

Rrna Genes ◽

Systematic Revision ◽

Rdna Sequences ◽

Relationship Of ◽

Rna Genes

Trypanosoma (Herpetosoma) grosi, which naturally parasitizesApodemusspp., can experimentally infect Mongolian jirds (Meriones unguiculatus). Three isolates fromA. agrarius,A. peninsulae, andA. speciosus(named SESUJI, HANTO, and AKHA isolates, respectively) of different geographical origin (AKHA from Japan, and the others from Vladivostok), exhibited different durations of parasitaemia in laboratory jirds (2 weeks for HANTO, and 3 weeks for the others). To assess the genetic background of theseT. grosiisolates, their small (SSU) and large subunit (LSU) ribosomal RNA genes (rDNA) were sequenced along with those of 2 otherHerpetosomaspecies from squirrels. The SSU rDNA sequences of these 3 species along with available sequences of 3 otherHerpetosomatrypanosomes (T. lewisi,T. musculiandT. microti)seemed to reflect well the phylogenetic relationship of their hosts. Three isolates ofT. grosiexhibited base changes at 2–6 positions of 2019-base 18S rDNA, at 5–29 positions of 1817/1818-base 28Sα rDNA, or 1–5 positions of 1557–1559-base 28Sβ rDNA, and none was separated from the other 2 isolates by rDNA nucleotide sequences. Since base changes ofHerpetosomatrypanosomes at the level of inter- and intra-species might occur frequently in specified rDNA regions, the molecular analysis on these regions of rodent trypanosomes could help species/strain differentiation and systematic revision ofHerpetosomatrypanosome species, which must be more abundant than presently known.

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Two new species and two new records of myxomycetes from subtropical forests in China

Phytotaxa ◽

10.11646/phytotaxa.350.1.6 ◽

2018 ◽

Vol 350 (1) ◽

pp. 51 ◽

Cited By ~ 1

Author(s):

YANG GAO ◽

SHU-ZHEN YAN ◽

GAO-WEI WANG ◽

SHUANG-LIN CHEN

Keyword(s):

New Species ◽

New Records ◽

Phylogenetic Analyses ◽

Diagnostic Feature ◽

Subtropical Forests ◽

Rdna Sequences ◽

Two New Species ◽

18S Rdna Sequences ◽

First Time ◽

Partial 18S

Two new myxomycetes from subtropical forests of China, Arcyria aeruginosa sp. nov. and Diderma subochraceum sp. nov., are described and illustrated. Arcyria aeruginosa occurred on rotten stem of bamboo and differs from all known species of the genus in having dense spines on inner surface of cups. The diagnostic feature of D. subochraceum is single-layered peridium which dehisces by longitudinal or stellate slit. Preliminary phylogenetic analyses based on partial 18S rDNA sequences support the establishment of the two new species. Additionally, Didymium saturnus H.W. Keller and Fuligo luteonitens L.G. Krieglst. & Nowotny are reported from China for the first time.

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Ichthyobodo salmonis sp. n. (Ichthyobodonidae, Kinetoplastida), an euryhaline ectoparasite infecting Atlantic salmon (Salmo salar L.)

Parasitology ◽

10.1017/s0031182011000916 ◽

2011 ◽

Vol 138 (9) ◽

pp. 1164-1175 ◽

Cited By ~ 7

Author(s):

TROND E. ISAKSEN ◽

EGIL KARLSBAKK ◽

KUNINORI WATANABE ◽

ARE NYLUND

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Phylogenetic Analyses ◽

Light And Electron Microscopy ◽

Morphological Characteristics ◽

Sensu Stricto ◽

Ssu Rdna ◽

Morphological Description ◽

Rdna Sequences ◽

Attachment Region

SUMMARYPhylogenetic analyses of SSU rDNA sequences have previously revealed the existence of 2 Ichthyobodo species able to infect Atlantic salmon (Salmo salar L.). Ichthyobodo necator sensu stricto (s.s.) is assumed to be a freshwater parasite, while a genetically distinct but undescribed species, Ichthyobodo sp. II sensu Todal et al. (2004) have been detected on Atlantic salmon in both fresh- and seawater. In the present study a morphological description of Ichthyobodo sp. II from the gills of salmon reared in fresh-, brackish- and seawater is presented, using both light- and electron microscopy. Comparative morphometry show that Ichthyobodo sp. II from both freshwater and seawater displays a different cell shape, and is significantly smaller than I. necator s.s. Also, ultrastructural characteristics distinguish these two species, notably differences in the attachment region and the presence of spine-like surface projections in Ichthyobodo sp. II. Based on both unique SSU rDNA sequences and morphological characteristics, we conclude that Ichthyobodo sp. II. represents a novel species for which we propose the name Ichthyobodo salmonis sp. n.

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Molecular data implicate bryozoans as hosts for PKX (Phylum Myxozoa) and identify a clade of bryozoan parasites within the Myxozoa

Parasitology ◽

10.1017/s003118209900520x ◽

1999 ◽

Vol 119 (6) ◽

pp. 555-561 ◽

Cited By ~ 60

Author(s):

C. L. ANDERSON ◽

E. U. CANNING ◽

B. OKAMURA

Keyword(s):

18S Rdna ◽

Phylogenetic Analyses ◽

Molecular Data ◽

Salmonid Fish ◽

Abnormal Immune Response ◽

Rdna Sequences ◽

Pectinatella Magnifica ◽

18S Rdna Sequences ◽

Cristatella Mucedo ◽

Distinct Taxon

Proliferative kidney disease (PKD), a condition associated with high mortality in salmonid fish, represents an abnormal immune response to the presence of an enigmatic myxozoan, which has been designated simply as PKX organism because its generic and specific status are obscure. Phylogenetic analyses of partial sequences of the 18S rDNA of PKX and of myxozoan parasites infecting the bryozoans Cristatella mucedo, Pectinatella magnifica and Plumatella rugosa, including the previously named Tetracapsula bryozoides from C. mucedo, showed that these taxa represent a distinct clade that diverged early in the evolution of the Myxozoa before the radiation of the other known myxozoan genera. A common feature of the myxozoans in this clade may be the electron-dense sporoplasmosomes with a lucent bar-like structure, which occur in T. bryozoides and PKX but not in the myxozoans belonging to the established orders Bivalvulida and Multivalvulida. Variation of 0·5–1·1% was found among the PKX 18S rDNA sequences obtained from fish from North America and Europe. The 18S rDNA sequence for T. bryozoides showed that it is a distinct taxon, not closely related to PKX but some sequences from myxozoans infecting 2 of the bryozoan species were so similar to those of PKX as to be indistinguishable. Other sequences from the new myxozoans in bryozoans at first appeared distinct from PKX in a maximum likelihood tree but, when analysed further, were also found to be phylogenetically indistinguishable from PKX. We propose that at least some variants of these new myxozoans from bryozoans are able to infect and multiply in salmonid fish, in which they stimulate the immune reaction and cause PKD but are unable to form mature spores to complete their development.

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