Molecular phylogeny of diploid Hordeum species and incongruence between chloroplast and nuclear datasets

Genome ◽  
2011 ◽  
Vol 54 (12) ◽  
pp. 986-992 ◽  
Author(s):  
Huan Wang ◽  
Dongfa Sun ◽  
Genlou Sun

The phylogeny of diploid Hordeum species has been studied using both chloroplast and nuclear gene sequences. However, the studies of different nuclear datasets of Hordeum species often arrived at similar conclusions, whereas the studies of different chloroplast DNA data generally resulted in inconsistent conclusions. Although the monophyly of the genus is well supported by both morphological and molecular data, the intrageneric phylogeny is still a matter of controversy. To better understand the evolutionary history of Hordeum species, two chloroplast gene loci (trnD-trnT intergenic spacer and rps16 gene) and one nuclear marker (thioreoxin-like gene (HTL)) were used to explore the phylogeny of Hordeum species. Two obviously different types of trnD-trnT sequences were observed, with an approximately 210 base pair difference between these two types: one for American species, another for Eurasian species. The trnD-trnT data generally separated the diploid Hordeum species into Eurasian and American clades, with the exception of Hordeum marinum subsp. gussoneanum. The rps16 data also grouped most American species together and suggested that Hordeum flexuosum has a different plastid type from the remaining American species. The nuclear gene HTL data clearly divided Hordeum species into two clades: the Xu + H genome clade and the Xa + I genome clade. Within clades, H genome species were well separated from the Xu species, and the I genome species were well separated from the Xa genome species. The incongruence between chloroplast and nuclear datasets was found and discussed.

2018 ◽  
Vol 5 (4) ◽  
pp. 171707 ◽  
Author(s):  
Aaron A. Heiss ◽  
Martin Kolisko ◽  
Fleming Ekelund ◽  
Matthew W. Brown ◽  
Andrew J. Roger ◽  
...  

Modern syntheses of eukaryote diversity assign almost all taxa to one of three groups: Amorphea, Diaphoretickes and Excavata (comprising Discoba and Metamonada). The most glaring exception is Malawimonadidae, a group of small heterotrophic flagellates that resemble Excavata by morphology, but branch with Amorphea in most phylogenomic analyses. However, just one malawimonad, Malawimonas jakobiformis , has been studied with both morphological and molecular-phylogenetic approaches, raising the spectre of interpretation errors and phylogenetic artefacts from low taxon sampling. We report a morphological and phylogenomic study of a new deep-branching malawimonad, Gefionella okellyi n. gen. n. sp. Electron microscopy revealed all canonical features of ‘typical excavates’, including flagellar vanes (as an opposed pair, unlike M. jakobiformis but like many metamonads) and a composite fibre. Initial phylogenomic analyses grouped malawimonads with the Amorphea-related orphan lineage Collodictyon , separate from a Metamonada+Discoba clade. However, support for this topology weakened when more sophisticated evolutionary models were used, and/or fast-evolving sites and long-branching taxa (FS/LB) were excluded. Analyses of ‘–FS/LB’ datasets instead suggested a relationship between malawimonads and metamonads. The ‘malawimonad+metamonad signal’ in morphological and molecular data argues against a strict Metamonada+Discoba clade (i.e. the predominant concept of Excavata). A Metamonad+Discoba clade should therefore not be assumed when inferring deep-level evolutionary history in eukaryotes.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ricardo Micolino ◽  
Maykon Passos Cristiano ◽  
Natália Martins Travenzoli ◽  
Denilce Meneses Lopes ◽  
Danon Clemes Cardoso

AbstractFungus-farming ants of the genus Mycetophylax exhibit intra and interspecific chromosome variability, which makes them suitable for testing hypotheses about possible chromosomal rearrangements that endure lineage diversification. We combined cytogenetic and molecular data from Mycetophylax populations from coastal environments to trace the evolutionary history of the clade in light of chromosomal changes under a historical and geographic context. Our cytogenetic analyses revealed chromosomal differences within and among species. M. morschi exhibited three distinct karyotypes and considerable variability in the localization of 45S rDNA clusters. The molecular phylogeny was congruent with our cytogenetic findings. Biogeographical and divergence time dating analyses estimated that the most recent common ancestor of Mycetophylax would have originated at about 30 Ma in an area including the Amazon and Southern Grasslands, and several dispersion and vicariance events may have occurred before the colonization of the Brazilian Atlantic coast. Diversification of the psammophilous Mycetophylax first took place in the Middle Miocene (ca. 18–10 Ma) in the South Atlantic coast, while “M. morschi” lineages diversified during the Pliocene-Pleistocene transition (ca. 3–2 Ma) through founder-event dispersal for the Northern coastal regions. Psammophilous Mycetophylax diversification fits into the major global climatic events that have had a direct impact on the changes in sea level as well as deep ecological impact throughout South America. We assume therefore that putative chromosomal rearrangements correlated with increased ecological stress during the past climatic transitions could have intensified and/or accompanied the divergence of the psammophilous Mycetophylax. We further reiterate that “M. morschi” comprises a complex of at least three well-defined lineages, and we emphasize the role of this integrative approach for the identification and delimitation of evolutionary lineages.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jouko Rikkinen ◽  
David A. Grimaldi ◽  
Alexander R. Schmidt

AbstractMyxomycetes constitute a group within the Amoebozoa well known for their motile plasmodia and morphologically complex fruiting bodies. One obstacle hindering studies of myxomycete evolution is that their fossils are exceedingly rare, so evolutionary analyses of this supposedly ancient lineage of amoebozoans are restricted to extant taxa. Molecular data have significantly advanced myxomycete systematics, but the evolutionary history of individual lineages and their ecological adaptations remain unknown. Here, we report exquisitely preserved myxomycete sporocarps in amber from Myanmar, ca. 100 million years old, one of the few fossil myxomycetes, and the only definitive Mesozoic one. Six densely-arranged stalked sporocarps were engulfed in tree resin while young, with almost the entire spore mass still inside the sporotheca. All morphological features are indistinguishable from those of the modern, cosmopolitan genus Stemonitis, demonstrating that sporocarp morphology has been static since at least the mid-Cretaceous. The ability of myxomycetes to develop into dormant stages, which can last years, may account for the phenotypic stasis between living Stemonitis species and this fossil one, similar to the situation found in other organisms that have cryptobiosis. We also interpret Stemonitis morphological stasis as evidence of strong environmental selection favouring the maintenance of adaptations that promote wind dispersal.


Phytotaxa ◽  
2017 ◽  
Vol 305 (2) ◽  
pp. 87
Author(s):  
SIRRI YÜZBAŞIOĞLU ◽  
IHSAN A. AL-SHEHBAZ ◽  
ELİF YÜZBAŞIOĞLU ◽  
EDA DALYAN

Berteroa physocarpa, a new species from the subalpine-alpine zone (1600−2200 m) of northwest Anatolia, is described and illustrated. It shares with the other species of Berteroa 2n=16 and morphologically is readily distinguished from them by having distinctly inflated fruit with glabrous valves. Sequences of nuclear ribosomal transcribed spacer (ITS) region were used to determine the relationship of Berteroa species using maximum likelihood methods. The phylogenetic results confirmed the recently established systematic history of Berteroa and also supported the recognition of this new species.


Zootaxa ◽  
2018 ◽  
Vol 4476 (1) ◽  
pp. 40
Author(s):  
RYAN J. THONI ◽  
DHAN B. GURUNG

Torrent catfishes of the subfamily Glyptosterninae from Bhutan are examined based on morphological and molecular data. Five new species are described: Creteuchiloglanis bumdelingensis sp. nov., Exostoma mangdechhuensis sp. nov., Parachiloglanis benjii sp. nov., P. dangmechhuensis sp. nov., and P. drukyulensis sp. nov. Molecular data derived from the mitochondrial gene Cyt b and the nuclear gene RAG2 recovered relationships within Parachiloglanis and the Glyptosterninae. A dichotomous key to the Glyptosterninae of Bhutan is provided.


Zootaxa ◽  
2004 ◽  
Vol 634 (1) ◽  
pp. 1 ◽  
Author(s):  
Oscar Arribas ◽  
Salvador Carranza

Iberolacerta cyreni martinezricai is elevated to the species level (I. martinezricai) based on both morphological and molecular data. The phylogenetic analysis using two mitochondrial and one nuclear gene shows I. martinezricai is more closely related to I. monticola than to I. cyreni. A multivariate analysis of the morphological data also supports the affinities between I. martinezricai and I. monticola but, at the same time, clearly indicates that I. martinezricai is morphologically distinct from both I. monticola and I. cyreni. The molecular data suggests I. cyreni and the clade formed by I. monticola + I. martinezricai split approximately 6.1 Mya, during the Mesinian Salinity Crisis, when climatic conditions around the Mediterranean area changed dramatically as a result of the desiccation of the Mediterranean Sea. Separation between I. martinezricai and I. monticola occurred approximately 2 Mya but, with at least two equally plausible alternative hypotheses, their biogeography is still unclear. New data on the habitat and distribution of I. martinezricai indicates its distribution area is very small (12 15 km 2 ), and that it lives in a climatically extreme habitat for this kind of mountain species. As a result of that and the low numbers of individuals, I. martinezricai is considered here as Critically Endangered.


2011 ◽  
Vol 279 (1731) ◽  
pp. 1093-1099 ◽  
Author(s):  
Maria Heikkilä ◽  
Lauri Kaila ◽  
Marko Mutanen ◽  
Carlos Peña ◽  
Niklas Wahlberg

Although the taxonomy of the ca 18 000 species of butterflies and skippers is well known, the family-level relationships are still debated. Here, we present, to our knowledge, the most comprehensive phylogenetic analysis of the superfamilies Papilionoidea, Hesperioidea and Hedyloidea to date based on morphological and molecular data. We reconstructed their phylogenetic relationships using parsimony and Bayesian approaches. We estimated times and rates of diversification along lineages in order to reconstruct their evolutionary history. Our results suggest that the butterflies, as traditionally understood, are paraphyletic, with Papilionidae being the sister-group to Hesperioidea, Hedyloidea and all other butterflies. Hence, the families in the current three superfamilies should be placed in a single superfamily Papilionoidea. In addition, we find that Hedylidae is sister to Hesperiidae, and this novel relationship is supported by two morphological characters. The families diverged in the Early Cretaceous but diversified after the Cretaceous–Palaeogene event. The diversification of butterflies is characterized by a slow speciation rate in the lineage leading to Baronia brevicornis , a period of stasis by the skippers after divergence and a burst of diversification in the lineages leading to Nymphalidae, Riodinidae and Lycaenidae.


2016 ◽  
Vol 128 (1) ◽  
pp. 12 ◽  
Author(s):  
Michael J. Bayly

The eucalypt group includes seven genera: Eucalyptus, Corymbia, Angophora, Eucalyptopsis, Stockwellia, Allosyncarpia and Arillastrum. Knowledge of eucalypt phylogeny underpins classification of the group, and facilitates understanding of their ecology, conservation and economic use, as well as providing insight into the history of Australia’s flora. Studies of fossils and phylogenetic analyses of morphological and molecular data have made substantial contributions to understanding of eucalypt relationships and biogeography, but relationships among some genera are still uncertain, and there is controversy about generic circumscription of the bloodwood eucalypts (genus Corymbia). Relationships at lower taxonomic levels, e.g. among sections and series of Eucalyptus, are also not well resolved. Recent advances in DNA sequencing methods offer the ability to obtain large genomic datasets that will enable improved understanding of eucalypt evolution.


2006 ◽  
Vol 189 (4) ◽  
pp. 1238-1243 ◽  
Author(s):  
Page W. Caufield ◽  
Deepak Saxena ◽  
David Fitch ◽  
Yihong Li

ABSTRACT There are suggestions that the phylogeny of Streptococcus mutans, a member of the human indigenous biota that is transmitted mostly mother to child, might parallel the evolutionary history of its human host. The relatedness and phylogeny of plasmid-containing strains of S. mutans were examined based on chromosomal DNA fingerprints (CDF), a hypervariable region (HVR) of a 5.6-kb plasmid, the rRNA gene intergenic spacer region (IGSR), serotypes, and the genotypes of mutacin I and II. Plasmid-containing strains were studied because their genetic diversity was twice as great as that of plasmid-free strains. The CDF of S. mutans from unrelated human hosts were unique, except those from Caucasians, which were essentially identical. The evolutionary history of the IGSR, with or without the serotype and mutacin characters, clearly delineated an Asian clade. Also, a continuous association with mutacin II could be reconstructed through an evolutionary lineage with the IGSR, but not for serotype e. DNA sequences from the HVR of the plasmid produced a well-resolved phylogeny that differed from the chromosomal phylogeny, indicating that the horizontal transfer of the plasmid may have occurred multiple times. The plasmid phylogeny was more congruent with serotype e than with mutacin II evolution, suggesting a possible functional correlation. Thus, the history of this three-tiered relationship between human, bacterium, and plasmid supported both coevolution and independent evolution.


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