Phylogenetic relationships among Coregonus species inferred from the DNA sequence of the first internal transcribed spacer (ITS1) of ribosomal DNA

1997 ◽  
Vol 54 (7) ◽  
pp. 1494-1503 ◽  
Author(s):  
S L Sajdak ◽  
R B Phillips
Keyword(s):  
Ribosomal Dna ◽  
North American ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Nuclear Gene ◽  
Molecular Data ◽  
Base Pairs ◽  
Phylogenetic Hypotheses ◽  
Northwestern North America ◽  
Hybridization And Introgression

Phylogenetic analyses based on morphometrics, data on protein electrophoresis, and mitochondrial DNA have given conflicting phylogenetic hypotheses for the subfamily Coregoninae (Prosopium, Coregonus, and Stenodus). To resolve these conflicts, phylogenetic analysis of 13 taxa of Coregoninae was done using a nuclear gene, the first internal transcribed spacer (ITS1) of the ribosomal DNA (rDNA). ITS1 sequences of all North American ciscoes were identical. In agreement with analyses based on other molecular data, the genus Stenodus was included in Coregonus, and there was no support for the monophyly of the ciscoes. The analysis based on rDNA also placed C. peled as the sister species to C. lavaretus, but this may represent a case of hybridization and introgression. A length polymorphism involving a repeating unit of 65-67 base pairs was found in the ITS1. All ciscoes except C. peled had one copy of the repeat. Coregonus peled, C. lavaretus, and Eurasian and Beringian C. clupeaformis had two copies of the repeat, while the other North American C. clupeaformis had three copies, suggesting that C. clupeaformis of northwestern North America is a form of C. lavaretus.

Phylogenetic analysis of Gyrodactylus spp. (Platyhelminthes: Monogenea) using ribosomal DNA sequences

1999 ◽  
Vol 77 (9) ◽  
pp. 1439-1449 ◽  
Author(s):  
J Cable ◽  
P D Harris ◽  
R C Tinsley ◽  
C M Lazarus
Keyword(s):  
Ribosomal Dna ◽  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Species Group ◽  
Internal Transcribed Spacers ◽  
Base Pairs ◽  
Separate Species ◽  
5.8S Rdna ◽  
Complete Sequences

Species of the viviparous monogenean genus Gyrodactylus are difficult to identify morphologically and relationships within the genus are unclear. Partial or complete sequences were obtained for the internal transcribed spacers (ITS-1 and ITS-2) and 5.8S ribosomal DNA (rDNA) of 11 Gyrodactylus species (G. kobayashii, G. gurleyi, G. pungitii, G. rogatensis, G. gasterostei, G. derjavini, G. salaris, G. rarus, G. turnbulli, G. bullatarudis, and G. arcuatus) and the related Gyrdicotylus gallieni. Phylogenetic analyses (parsimony, distance, and maximum likelihood) separated species of the Gyrodactylus wageneri species-group (with a long ITS-1) from those of the Gyrodactylus eucaliae and G. arcuatus species-groups (with a short ITS-1). This subdivision into species with a long (610-630 base pairs (bp)) or short (300-500 bp) ITS-1 was also apparent with 5.8S rDNA and ITS-2 data. No support could be found for the hypothesis that G. salaris is a member of a separate species group, as this species clustered within the G. wageneri group. The morphologically homogeneous G. wageneri group was subdivided by our molecular data into five species that infect cottids, gasterosteids, and salmonids and two species that infect cyprinid fishes. Overall, the ITS-2, combined with the 5.8S rDNA (an alignment of 668 bp), appeared to be the most informative indicator of phylogenetic relationships within the genus Gyrodactylus. The potential importance of this technique for future gyrodactylid systematics is discussed.

scholarly journals Taxonomic revision of Russula subsection Amoeninae from South Korea

MycoKeys ◽  
2020 ◽  
Vol 75 ◽  
pp. 1-29
Author(s):  
Komsit Wisitrassameewong ◽  
Myung Soo Park ◽  
Hyun Lee ◽  
Aniket Ghosh ◽  
Kanad Das ◽  
...  
Keyword(s):  
New Species ◽  
South Korea ◽  
Central America ◽  
North American ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Taxonomic Revision ◽  
Molecular Phylogenetic ◽  
Pileus Surface ◽  
A New Species

Russula subsection Amoeninae is morphologically defined by a dry velvety pileus surface, a complete absence of cystidia with heteromorphous contents in all tissues, and spores without amyloid suprahilar spot. Thirty-four species within subsection Amoeninae have been published worldwide. Although most Russula species in South Korea have been assigned European or North American names, recent molecular studies have shown that Russula species from different continents are not conspecific. Therefore, the present study aims to: 1) define which species of Russula subsection Amoeninae occur on each continent using molecular phylogenetic analyses; 2) revise the taxonomy of Korean Amoeninae. The phylogenetic analyses using the internal transcribed spacer (ITS) and multilocus sequences showed that subsection Amoeninae is monophyletic within subgenus Heterophyllidiae section Heterophyllae. A total of 21 Russula subsection Amoeninae species were confirmed from Asia, Australia, Europe, North America, and Central America, and species from different continents formed separate clades. Three species were recognized from South Korea and were clearly separated from the European and North American species. These species are R. bella, also reported from Japan, a new species described herein, Russula orientipurpurea, and a new species undescribed due to insufficient material.

A revision of the Leptogium saturninum group in North America

2016 ◽  
Vol 48 (5) ◽  
pp. 387-421 ◽  
Author(s):  
Daphne F. STONE ◽  
James W. HINDS ◽  
Frances L. ANDERSON ◽  
James C. LENDEMER
Keyword(s):  
North American ◽  
Morphological Study ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Lower Surface ◽  
Molecular Data ◽  
The North ◽  
Molecular Phylogenetic ◽  
Nrits Sequence

AbstractA revision of the North American members of the Leptogium saturninum group (i.e. species with long lower-surface hairs, isidia, and usually smooth upper surface) is presented based on molecular phylogenetic analyses of mtSSU and nrITS sequence data, together with an extensive morphological study. Three species supported by both molecular and morphological characteristics are recognized: L. acadiense sp. nov. (distinguished by granular saturninum-type isidia, medulla composed of irregularly arranged or perpendicular hyphae), L. cookii sp. nov. (distinguished by cylindrical saturninum-type isidia) and L. hirsutum (distinguished by hirsutum-type isidia and medulla composed of loosely intertwined hyphae). One species supported by morphological characteristics, but for which no molecular data could be generated, is also recognized: L. compactum sp. nov. (distinguished by hirsutum-type isidia and medulla composed of tightly packed hyphae). Finally, L. saturninum (distinguished by granular saturninum-type isidia and medulla composed of perpendicular and parallel hyphae) is supported by morphological characteristics but molecular data from geographically diverse populations, including those near the type locality, indicate that the morphologically defined species is paraphyletic. Leptogium burnetiae is excluded from North American based on morphological study of the type. The species are described and illustrated in detail, and are distinguished morphologically by their isidium development, morphology of mature isidia, and pattern of hyphae in the medulla in transverse sections near lobe margins. A key to the members of the L. saturninum group and related species is also presented.

Phylogenetic analyses of Nematoctonus and Hohenbuehelia (Pleurotaceae)

2007 ◽  
Vol 85 (8) ◽  
pp. 762-773 ◽  
Author(s):  
Alexandra T.E. Koziak ◽  
Kei Chin Cheng ◽  
R. Greg Thorn
Keyword(s):  
Ribosomal Dna ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Nuclear Ribosomal Dna ◽  
Monophyletic Clade ◽  
Parasitoid Species ◽  
Internal Transcribed Spacer Region ◽  
Species Limits ◽  
Additional Gene

Hohenbuehelia (Agaricales, Pleurotaceae) and Nematoctonus (Hyphomycetes) are the names for the sexual and asexual stages of a genus of nematode-destroying fungi (Basidiomycota). We obtained partial sequences of nuclear ribosomal DNA, including the internal transcribed spacer region and the 5′ end of the large subunit, of 37 isolates of Hohenbuehelia and Nematoctonus representing 13 of the 16 described species in Nematoctonus. Phylogenetic analyses support Hohenbuehelia–Nematoctonus as a monophyletic clade of the Pleurotaceae, within which the species were placed in five main subclades. Exclusively predatory species ( Nematoctonus brevisporus Thorn & G.L. Barron, Nematoctonus campylosporus Drechsler, Nematoctonus robustus F.R. Jones, and Nematoctonus sp. UAMH 5317) appear to be basal. In these species, adhesive knobs to capture prey are produced on their hyphae but not on their conidia. A single mycelial individual may feed on many nematodes. From these have arisen both exclusively parasitoid species ( Nematoctonus cylindrosporus Thorn & G.L. Barron, Nematoctonus leiosporus Drechsler, Nematoctonus leptosporus Drechsler, Nematoctonus pachysporus Drechsler, Nematoctonus tylosporus Drechsler), and species that we call intermediate predators ( Nematoctonus angustatus Thorn & G.L. Barron, Nematoctonus concurrens Drechsler, Nematoctonus geogenius Thorn & GL. Barron, Nematoctonus hamatus Thorn & G.L. Barron, and Nematoctonus subreniformis Thorn & G.L. Barron). Exclusively parasitoid species have conidia that germinate to form sticky knobs that attach to passing nematodes but lack adhesive knobs on the hyphae. Each mycelial individual feeds on only one nematode. Intermediate predators have adhesive knobs both on hyphae and on germinated conidia and can act in both predatory and parasitoid modes. Most morphospecies are resolved as monophyletic, but sequences of additional gene regions are required to clarify species limits within the N. angustatus – N. geogenius group.

Ascomal evolution of filamentous ascomycetes: evidence from molecular data

1995 ◽  
Vol 73 (S1) ◽  
pp. 811-815 ◽  
Author(s):  
Joseph W. Spatafora
Keyword(s):  
Maximum Likelihood ◽  
Ribosomal Dna ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Small Subunit ◽  
Filamentous Ascomycete ◽  
Group 4 ◽  
Nucleotide Data ◽  
Group 2 ◽  
Parsimony Trees

Phylogenetic analyses of nucleotide data from partial sequences (1150 bp) of the small subunit ribosomal DNA (SSU rDNA) were performed on 30 taxa representing several orders of Hymenoascomycetes and Loculoascomycetes. These analyses detected four major groups of filamentous ascomycetes: group 1, pyrenomycetes (Hypocreales, Microascales, Diaporthales, Sordariales) and loculoascomycetes (Pleosporales); group 2, operculate discomycetes (Pezizales); group 3, inoperculate discomycetes (Geoglossaceae); and group 4, plectomycetes (Eurotiales, Onygenales) and loculoascomycetes (Chaetothyriales). Well-supported clades, which correspond to groupings based on ascomal morphology, were resolved; however, the monophyly of the classes Hymenoascomycetes and Loculoascomycetes was rejected. The placement of the root on the filamentous ascomycete ingroup proved more problematic than resolving the ingroup relationships. Three alternative rooting possibilities, which were identified in suboptimal parsimony trees, were not significantly less likely in maximum likelihood ratio tests. Nonetheless, the most likely topology obtained from fastDNAml was identical to the most parsimonious tree. Key words: filamentous ascomycetes, Hymenoascomycetes, Loculoascomycetes, parsimony, maximum likelihood, ribosomal DNA.

scholarly journals A preliminary survey of zoantharian endosymbionts shows high genetic variation over small geographic scales on Okinawa-jima Island, Japan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3740 ◽  
Author(s):  
Hatsuko Noda ◽  
John Everett Parkinson ◽  
Sung-Yin Yang ◽  
James Davis Reimer
Keyword(s):  
Internal Transcribed Spacer ◽  
Environmental Variability ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Species Level ◽  
Sea Surface ◽  
Fine Scale ◽  
Clade C ◽  
Symbiotic Dinoflagellates ◽  
The Common

Symbiotic dinoflagellates (genus Symbiodinium) shape the responses of their host reef organisms to environmental variability and climate change. To date, the biogeography of Symbiodinium has been investigated primarily through phylogenetic analyses of the ribosomal internal transcribed spacer 2 region. Although the marker can approximate species-level diversity, recent work has demonstrated that faster-evolving genes can resolve otherwise hidden species and population lineages, and that this diversity is often distributed over much finer geographical and environmental scales than previously recognized. Here, we use the noncoding region of the chloroplast psbA gene (psbAncr) to examine genetic diversity among clade C Symbiodinium associating with the common reef zoantharian Palythoa tuberculosa on Okinawa-jima Island, Japan. We identify four closely related Symbiodinium psbAncr lineages including one common generalist and two potential specialists that appear to be associated with particular microhabitats. The sea surface temperature differences that distinguish these habitats are smaller than those usually investigated, suggesting that future biogeographic surveys of Symbiodinium should incorporate fine scale environmental information as well as fine scale molecular data to accurately determine species diversity and their distributions.

scholarly journals A novel Arabidopsis phyllosphere resident Protomyces species and a re-examination of genus Protomyces based on genome sequence data

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Wang ◽  
Timo Sipilä ◽  
Kirk Overmyer
Keyword(s):  
Dna Sequences ◽  
Internal Transcribed Spacer ◽  
Host Plants ◽  
Sequence Data ◽  
Nuclear Gene ◽  
Molecular Data ◽  
Rapid Identification ◽  
Nuclear Ribosomal Dna ◽  
Species Relationships ◽  
Internal Transcribed Spacer Sequences

AbstractProtomyces is an understudied genus of yeast-like fungi currently defined as phytopathogens of only Umbelliferae and Compositae. Species relationships and boundaries remain controversial and molecular data are lacking. Of the 82 named Protomyces, we found few recent studies and six available cultures. We previously isolated Protomyces strains from wild Arabidopsis thaliana, a member of Brassicaceae, a family distant from accepted Protomyces hosts. We previously sequenced the genomes of all available Protomyces species, and P. arabidopsidicola sp. nov. strain C29, from Arabidopsis. Phylogenomics suggests this new species occupied a unique position in the genus. Genomic, morphological, and physiological characteristics distinguished P. arabidopsidicola sp. nov. from other Protomyces. Nuclear gene phylogenetic marker analysis suggests actin1 gene DNA sequences could be used with nuclear ribosomal DNA internal transcribed spacer sequences for rapid identification of Protomyces species. Previous studies demonstrated P. arabidopsidicola sp. nov. could persist on the Arabidopsis phyllosphere and Protomyces sequences were discovered on Arabidopsis at multiple sites in different countries. We conclude that the strain C29 represents a novel Protomyces species and propose the name of P. arabidopsidicola sp. nov. Consequently, we propose that Protomyces is not strictly associated only with the previously recognized host plants.

scholarly journals Which morphological characters are influential in a Bayesian phylogenetic analysis? Examples from the earliest osteichthyans

2019 ◽  
Vol 15 (7) ◽  
pp. 20190288 ◽  
Author(s):  
Benedict King
Keyword(s):  
Bayesian Analysis ◽  
Tooth Enamel ◽  
Simple Procedure ◽  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Molecular Data ◽  
Body Parts ◽  
Bayesian Phylogenetic Analysis ◽  
Recent Debate ◽  
Phylogenetic Hypotheses

There has been much recent debate about which method is best for reconstructing the tree of life from morphological datasets. However, little attention has been paid to which characters, if any, are responsible for topological differences between trees recovered from competing methods on empirical datasets. Indeed, a simple procedure for finding characters supporting conflicting tree topologies is available in a parsimony framework, but an equivalent procedure in a model-based framework is lacking. Here, I introduce such a procedure and apply it to the problem of the ‘psarolepid’ osteichthyans. The ‘psarolepids’, which include the earliest known osteichthyans, are weakly supported as stem osteichthyans under parsimony but strongly supported as sarcopterygians in Bayesian analysis. The Bayesian result is driven by just two characters, both of which relate to the intracranial joint of sarcopterygians. Important characters that support a stem osteichthyan affinity for ‘psarolepids’, such as the absence of tooth enamel, have virtually no effect in a Bayesian framework. This is because of a bias towards characters with relatively complete sampling, a bias that has previously been reported for molecular data. This has important implications for Bayesian analysis of morphological datasets in general, as characters from different body parts commonly have different levels of coding completeness. Methods to critically appraise character support for conflicting phylogenetic hypotheses, such as that used here, should form an important part of phylogenetic analyses.

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