Description and experimental transmission of Tetracapsuloides vermiformis n. sp. (Cnidaria: Myxozoa) and guidelines for describing malacosporean species including reinstatement of Buddenbrockia bryozoides n. comb. (syn. Tetracapsula bryozoides)

Parasitology ◽  
2016 ◽  
Vol 144 (4) ◽  
pp. 497-511 ◽  
Author(s):  
SNEHA PATRA ◽  
ASHLIE HARTIGAN ◽  
DAVID J. MORRIS ◽  
ALENA KODÁDKOVÁ ◽  
ASTRID S. HOLZER
Keyword(s):  
Dna Sequences ◽  
Sequence Data ◽  
Morphological Characters ◽  
Experimental Transmission ◽  
Rdna Sequence Data ◽  
Differential Characters ◽  
Present Description ◽  
Fredericella Sultana ◽  
18S Rdna Sequence ◽  
Molecular Characters

SUMMARYThis paper provides the first detailed description of a Tetracapsuloides species, Tetracapsuloides vermiformis n. sp., with vermiform stages in the bryozoan host, Fredericella sultana, and its experimental transmission from F. sultana to Cyprinus carpio. The suitability of morphological, biological and 18S rDNA sequence data for discrimination between malacosporean species is reviewed and recommendations are given for future descriptions. Presently, malacosporean species cannot be differentiated morphologically due to their cryptic nature and the lack of differential characters of spores and spore-forming stages in both hosts. We examined biological, morphological and molecular characters for the present description and for revising malacosporean taxonomy in general. As a result, Buddenbrockia plumatellae was split into two species, with its sac-like stages being ascribed to Buddenbrockia bryozoides n. comb. In addition to ribosomal DNA sequences multiple biological features rather than morphological characters are considered essential tools to improve malacosporean taxonomy in the future according to our analysis of the limited traits presently available.

Further phylogenetic studies of the Polychaeta using 18S rDNA sequence data

2004 ◽  
Vol 84 (5) ◽  
pp. 949-960 ◽  
Author(s):  
Kathryn A. Hall ◽  
Pat A. Hutchings ◽  
Donald J. Colgan
Keyword(s):  
Dna Sequences ◽  
Sequence Data ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Morphological Data ◽  
Phylogenetic Studies ◽  
Rdna Sequence Data ◽  
Substantial Progress ◽  
18S Rdna Sequence

The integration of molecular and morphological approaches has produced substantial progress in understanding the higher classification of most major invertebrate groups. The striking exception to this is the Polychaeta. Neither the membership nor the higher classification of this group has been robustly established. Major inconsistencies exist between the only comprehensive cladistic analysis of Polychaeta using morphological data and the DNA sequence studies covering all or part of the taxon.We have compiled a dataset of available nearly complete 18S ribosomal DNA sequences and collected an additional 22 sequences (20 Polychaeta in 19 taxa, one Myzostomida and one Phoronida) to obtain more comprehensive coverage of polychaete diversity for this gene. Analyses of the data do not resolve all inconsistencies among current hypotheses of polychaete phylogeny. They do support the recognition (in whole or part) of some clades such as the Eunicida, Phyllodocida and Terebellida that have been proposed on morphological grounds. Our analyses contradict the Canalipalpata and the Scolecida. Although the polychaete sister-group to the Clitellata is not clearly resolved in our analyses, the clitellates are always recovered as a derived clade within the Polychaeta. Increased taxon sampling is required to elucidate further the phylogeny of the Polychaeta.

Phylogenetic relationships of Nygolaimina and Dorylaimina (Nematoda: Dorylaimida) inferred from small subunit ribosomal DNA sequences

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 59-79 ◽  
Author(s):  
Peter G. Mullin ◽  
Timothy S. Harris ◽  
Thomas O. Powers
Keyword(s):  
Dna Sequences ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Small Subunit ◽  
Sister Taxon ◽  
Monophyletic Lineage ◽  
Rdna Sequence Data ◽  
The Common ◽  
Small Subunit Ribosomal Dna ◽  
18S Rdna Sequence

Abstract Phylogenetic reconstructions based on 18S rDNA sequence data indicate that Dorylaimida, comprising the suborders Nygolaimina and Dorylaimina, is a monophyletic lineage, but that there is a deep division within Nygolaimina, giving rise to the possibility that Nygolaimina is paraphyletic. A well-supported clade comprising members of the traditional orders Mermithida and Mononchida (including Bathyodontina) forms the sister taxon to the Dorylaimida. Inferred relationships within this clade indicate that Mermithida shares more recent common ancestry with Mononchina than does Bathyodontina. Vertebrate parasites within Dorylaimia (Dioctophymida and Trichinellida) are reconstructed in a sister-taxon relationship with the Mononchida/Dorylaimida lineage. The enigmatic order Isolaimida (represented by Isolaimium) appears to be ancestral to all other Dorylaimia sampled. Expanded taxon sampling for phylogenetic analyses of the subclass raises new possibilities for the reconstruction of hypothetical character states in the common ancestor of Dorylaimia.

Molecular phylogeny of the Platyhelminthes

2004 ◽  
Vol 82 (2) ◽  
pp. 168-193 ◽  
Author(s):  
Jaume Baguñà ◽  
Marta Riutort
Keyword(s):  
Molecular Phylogeny ◽  
Hox Genes ◽  
Sequence Data ◽  
Sister Group ◽  
Main Difficulty ◽  
Rdna Sequence Data ◽  
Corroborative Evidence ◽  
18S Rdna Sequence ◽  
Basal Position ◽  
Molecular Characters

The phylum Platyhelminthes has traditionally been considered the most basal bilaterian taxon. The main difficulty with this placement is the lack of convincing synapomorphies for all Platyhelminthes, which suggest that they are polyphyletic. Recent molecular findings based on 18S rDNA sequence data and number and type of Hox genes strongly suggest that the majority of Platyhelminthes are members of the lophotrochozoan protostomes, whereas the Acoelomorpha (Acoela + Nemertodermatida) fall outside of the Platyhelminthes as the most basal bilaterian taxon. Here we review phylum-wide analyses based on complete ribosomal and other nuclear genes addressed to answer the main issues facing systematics and phylogeny of Platyhelminthes. We present and discuss (i) new corroborative evidence for the polyphyly of the Platyhelminthes and the basal position of Acoelomorpha; (ii) a new consensus internal tree of the phylum; (iii) the nature of the sister group to the Neodermata and the hypotheses on the origin of parasitism; and (iv) the internal phylogeny of some rhabditophoran orders. Some methodological caveats are also introduced. The need to erect a new phylum, the Acoelomorpha, separate from the Platyhelminthes (now Catenulida + Rhabditophora) and based on present and new morphological and molecular characters is highlighted, and a proposal made.

Phylogenetic relationships among taxa in the Jahnulales inferred from 18S and 28S nuclear ribosomal DNA sequences

2007 ◽  
Vol 85 (9) ◽  
pp. 873-882 ◽  
Author(s):  
Jinx Campbell ◽  
Astrid Ferrer ◽  
Huzefa A. Raja ◽  
Somsak Sivichai ◽  
Carol A. Shearer
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Sequence Data ◽  
Molecular Study ◽  
Morphological Characters ◽  
Nuclear Ribosomal Dna ◽  
Morphological Data ◽  
Rdna Sequence Data ◽  
28S Rdna Sequence ◽  
Important Character

Jahnulales is an order of freshwater, lignicolous, bitunicate ascomycetes characterized by wide (10–40 μm), brown, septate hyphae, stalked and (or) sessile ascomata, ascomal walls of 2–6 layers of large cells, and 1-septate ascospores. A variety of ascospore modifications are represented among the species in the order, including wall roughening, gelatinous sheaths, appendages and (or) pads, and apical caps or spines. To clarify generic boundaries and phylogenetic relationships within the Jahnulales and to assess the taxonomic significance of various morphological characters, a molecular study was carried out using 18S and 28S rDNA sequence data from 15 species representing the four genera in the order. In addition, Brachiosphaera tropicalis Nawawi and Xylomyces chlamydosporus Goos, R.D. Brooks & Lamore, two mitosporic species that co-occur with Jahnula Kirschst., species and have wide (>10 μm), brown, septate hyphae were included in the study to determine whether these species are members of this order. Maximum likelihood analyses confirmed the monophyly of the Jahnulales and resolved four clades. Two robustly supported clades comprise the genera Aliquandostipite Inderb. and Megalohypha A. Ferrer & Shearer. A third well-supported clade encompassed species of Brachiosphaera , Jahnula , and Xylomyces . The fourth clade contained isolates of the type species of the genus Jahnula, Jahnula aquatica (Plöttn. & Kirschst.) Kirschst., and two other members of this genus, but this clade was weakly supported. Our data suggest that the presence of very wide, brown, septate hyphae is an important character defining the Jahnulales. Based on molecular and morphological data, we propose the transfer of Jahnula siamensiae Sivichai & E.B.G. Jones and Patescospora separans Abdel-Wahab & El-Shar. to Aliquandostipite and emend the description of the Jahnulales.

Phylogenetic analyses of various euglenoid taxa (euglenozoa) based on 18s rdna sequence data

2000 ◽  
Vol 36 (1) ◽  
pp. 220-226 ◽  
Author(s):  
Angelika Preisfeld ◽  
Silke Berger ◽  
Ingo Busse ◽  
Susanne Liller ◽  
Hans Georg Ruppel
Keyword(s):  
18S Rdna ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Rdna Sequence ◽  
Rdna Sequence Data ◽  
18S Rdna Sequence

On the phylogeny of Ophiostoma, Ceratocystis s.s., and Microascus, and relationships within Ophiostoma based on partial ribosomal DNA sequences

1993 ◽  
Vol 71 (9) ◽  
pp. 1249-1265 ◽  
Author(s):  
G. Hausner ◽  
J. Reid ◽  
G. R. Klassen
Keyword(s):  
Dna Sequences ◽  
Sequence Data ◽  
Large Subunit ◽  
Small Subunit ◽  
Data Set ◽  
Rdna Sequences ◽  
Morphological Criteria ◽  
Small Subunit Rdna ◽  
Rdna Sequence Data ◽  
Large Subunit Rdna

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.

Molecular systematics of subtribe Banksiinae (Banksia and Dryandra; Proteaceae) Based on cpDNA and nrDNA sequence data: Implications for taxonomy and biogeography

1998 ◽  
Vol 11 (4) ◽  
pp. 321 ◽  
Author(s):  
Austin R. Mast
Keyword(s):  
Sequence Data ◽  
Phylogenetic Reconstruction ◽  
Morphological Characters ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Base Substitution ◽  
Trnl Intron ◽  
Single Root ◽  
Cladistic Analyses ◽  
Molecular Characters

Despite considerable research interest in the subtribe Banksiinae (Banksia L.f. and Dryandra R.Br.), no strongly supported phylogenetic hypothesis for the relationship between the genera exists, nor have molecular characters been sampled for phylogenetic reconstruction at any level. In this study, DNA sequence characters were sampled from chloroplast DNA (cpDNA; the trnL intron, the trnL 3′ exon, and the spacer between the trnL 3′ exon and trnF) and nuclear ribosomal DNA (nrDNA; both internal transcribed spacers) of 18 species of Banksia and five of Dryandra, with six outgroup taxa from the subfamily Grevilleoideae. The molecular characters provided the opportunity to code taxa outside of Banksia for cladistic comparison with the genus—an opportunity not previously provided by morphological characters. Cladistic analyses, using parsimony, explored the effects of various weightings of transition to transversion events and base substitution to insertion and deletion events to determine which relationships in the cladograms were robust. The trnL/trnF and ITS characters strongly supported a paraphyletic Banksia with respect to a monophyletic Dryandra. The molecular results supported a single root for Thiele and Ladiges’(1996) unrooted morphological cladogram along the branch between the Isotylis to B. fuscolutea clade and the Grandes to B. tricuspis clade. George’s (1981) subgenus Banksia and section Banksia appeared dramatically non-monophyletic. The distribution of eastern taxa at derived positions on the molecular cladograms suggested considerable cladogenesis in the the genus prior to the formation of the Nullarbor Plain during the Tertiary.

Primary species recognition and phylogeny of Chondrus (Gigartinales, Rhodophyta) using 18S rDNA sequence data

2007 ◽  
Vol 25 (2) ◽  
pp. 174-183
Author(s):  
Zimin Hu ◽  
Xiaoqi Zena ◽  
Alan T. Critchley ◽  
Steve L. Morrell ◽  
Delin Duan
Keyword(s):  
18S Rdna ◽  
Sequence Data ◽  
Species Recognition ◽  
Rdna Sequence ◽  
Rdna Sequence Data ◽  
18S Rdna Sequence

Ulva and Enteromorpha (Ulvales, Ulvophyceae, Chlorophyta) in eastern Australia: Comparison of morphological features and analyses of nuclear rDNA sequence data

1999 ◽  
Vol 12 (5) ◽  
pp. 709 ◽  
Author(s):  
Geoffrey W. Woolcott ◽  
Robert J. King
Keyword(s):  
Sequence Data ◽  
Morphological Plasticity ◽  
Morphological Characters ◽  
Australian Study ◽  
Internal Transcribed Spacer Region ◽  
Eastern Australia ◽  
Rdna Sequence Data ◽  
Ulva Australis ◽  
Potential Use

Specimens of Ulva Linnaeus and Enteromorpha Link (Ulvales, Ulvophyceae, Chlorophyta) were collected from 12 sites in eastern Australia and identified to species level on the basis of morphological characters described in the major Australian study of Womersley (1984). The species recognised were Ulva australis Areschoug, U. lactuca Linnaeus, U. fasciata Delile, Enteromorpha compressa (Linnaeus) Greville, E. flexuosa (Wulfen ex Roth) J.Agardh and E. intestinalis (Linnaeus) Link. Species placement within the genera Ulva and Enteromorpha is problematic and features of DNA were examined in order to assess their potential use as characters in species determinations. Analyses were conducted on sequence data derived from the internal transcribed spacer region ITS2, and the 5.8S gene. Groupings of the 12 isolates based on DNA analyses do not correlate with the species identified using morphology nor with the two genera. Further work is required before authoritative conclusions can be reached regarding the significance of morphological plasticity in determination of differences within and between Ulva and Enteromorpha species; nevertheless, DNA studies may provide a backbone of characters upon which to base such a study.

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