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.

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.

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.

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

scholarly journals Redescription, Morphogenesis, and Molecular Phylogeny of Pseudosincirra longicirrata nov. comb., With Establishment of a New Genus Pseudosincirra nov. gen. (Ciliophora, Hypotrichia)

2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Gao ◽  
Chen Shao ◽  
Qiuyue Tang ◽  
Jingbao Li
Keyword(s):  
Molecular Phylogeny ◽  
New Genus ◽  
Sequence Data ◽  
Southern China ◽  
Phylogenetic Analyses ◽  
Small Subunit ◽  
Ssu Rdna ◽  
Original Population ◽  
The Family ◽  
Rdna Sequence Data

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.

Generic delimitations in the family Stictidaceae (Ostropales, Ascomycota): the Stictis–Conotrema problem

2005 ◽  
Vol 37 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Mats WEDIN ◽  
Heidi DÖRING ◽  
Kristina KÖNBERG ◽  
Gunnar GILENSTAM
Keyword(s):  
Sequence Data ◽  
Sister Group ◽  
Lsu Rdna ◽  
Infrageneric Classification ◽  
Rdna Its ◽  
The Family ◽  
Rdna Sequence Data ◽  
Natural Groups ◽  
High Support

The family Stictidaceae (Ostropales, Ascomycota) contains both lichenized and non-lichenized fungi. Here, we test if Conotrema (lichenized) and Stictis (non-lichenized) as currently delimited are distinct monophyletic genera, by parsimony and parsimony jackknifing analyses of combined nuclear rDNA (ITS and partial LSU rDNA) and mitochondrial SSU rDNA sequence data matrices. The study includes four species of Stictis, three species of Conotrema, and representatives of the related Schizoxylon (lichenized), Odontotrema, Carestiella (at least sometimes associated with algae), Cryptodiscus and Thelotrema (lichenized). In all analyses, the Conotrema species were nested within Stictis with high support. Thus, we conclude that Conotrema are only lichenized representatives of Stictis. The type species of the two generic names, C. urceolatum and S. radiata, are sister taxa in our analyses. Furthermore, the analysis gave no support for the present infrageneric classification of Stictis. Carestiella socia (the type of Carestiella) and the two representatives of Schizoxylon studied were also nested within Stictis s. lat. The Odontotremataceae is the sister group to the Stictidaceae, and Cryptodiscus foveolaris groups with Thelotrema rather than with the Stictidaceae. We conclude that lichenization in the Stictidaceae does not characterize natural groups, and that Conotrema should be considered a synonym to Stictis, as predicted by anatomical characteristics. The new combinations Stictis urceolatum and Stictis populorum are made.

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

scholarly journals Old and Cosmopolite: Molecular Phylogeny of Tropical–Subtropical Kites (Aves: Elaninae) with Taxonomic Implications

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 327
Author(s):  
Ivan J. Starikov ◽  
Michael Wink
Keyword(s):  
Molecular Phylogeny ◽  
Genetic Markers ◽  
Sequence Data ◽  
Cyt B ◽  
Ecological Data ◽  
Dna Sequence Data ◽  
Family Level ◽  
Taxonomic Implications ◽  
Rag 1 ◽  
Basal Position

Kites of the Elaninae group are small and medium-sized, mostly tropical raptors traditionally considered as an early diverged subfamily of the Accipitridae. We used nucleotide sequences of three genetic markers (mitochondrial Cyt b and COI, nuclear RAG-1) to reconstruct the phylogenetic relationships of the Elaninae, other kites, and representatives of different families of diurnal raptors. Our results confirm the basal position of Elaninae, separated the latest in Early Miocene, including Chelictinia riocourii, which was not sequenced before and belongs to this group. Not only DNA data but also cytological, morphological, and ecological data show the singularity of Elaninae. We suggest elevating this group to family level as Elanidae within the order Accipitriformes. It includes Gampsonyx swainsonii as a monotypic subfamily because of distinctive traits and DNA sequence data. Taxonomic implications for other macrogroups of Accipitriformes are discussed.

On the systematic position of the lichen genus Heppia

2003 ◽  
Vol 35 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Matthias Schultz ◽  
Burkhard Büdel
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Bayesian Approach ◽  
Sequence Data ◽  
Systematic Position ◽  
The Family ◽  
Rdna Sequence Data ◽  
Family Level ◽  
18S Rdna Sequence

AbstractThe systematic position of the lichen genus Heppia in the order Lichinales was investigated. 18S rDNA sequence data were analyzed using a Bayesian approach to infer phylogeny using Markov chain Monte Carlo methods. The Lichinales are divided at family level into the sister groups Lichinaceae and Peltulaceae. The genus Heppia forms a highly supported clade in the family Lichinaceae. It is shown that the genus Heppia is morphologically well circumscribed within the Lichinaceae. As a nomenclatural consequence, the family name Heppiaceae is placed into synonymy under the older name Lichinaceae.

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