scholarly journals URA5 gene of Cryptococcus neoformans var. gattii: evidence for a close phylogenetic relationship between C. neoformans var. gattii and C. neoformans var. neoformans.

1992 ◽  
Vol 38 (5) ◽  
pp. 491-495 ◽  
Author(s):  
ARTURO CASADEVALL ◽  
MANXIA FAN
1970 ◽  
Vol 12 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Chi-Chang Chen ◽  
Pryce B. Gibson

Both Trifolium repens (2n = 32) and T. nigrescens (2n = 16) formed bivalents during meiosis. However, their triploid hybrid showed an average of 4.27 trivalents per microsporocyte at metaphase I. The frequency of trivalents in the hybrid between T. nigrescens and autotetraploid T. occidentale (2n = 32) was 5.69. The data are interpreted to indicate: (1) a possible autotetraploid origin of T. repens; and (2) a close phylogenetic relationship among T. repens, T. nigrescens and T. occidentale.


Nematology ◽  
2016 ◽  
Vol 18 (5) ◽  
pp. 517-536 ◽  
Author(s):  
Sergio Álvarez-Ortega ◽  
Thi Anh Duong Nguyen ◽  
Joaquín Abolafia ◽  
Thi Thanh Tam Vu ◽  
Michael Bonkowski ◽  
...  

Three new species of the genus Sectonema collected from natural habitats in Vietnam are studied, described and illustrated, including line drawings, LM and/or SEM pictures. Sectonema birrucephalum sp. n. is characterised by its 2.73-4.35 mm long body, lip region 18-20 μm broad and offset by deep constriction, odontostyle 10.0-11.5 μm long on its ventral side, 659-989 μm long neck, pharyngeal expansion occupying 63-68% of total neck length, uterus a simple tube, 221-277 μm long, pars refringens vaginae present, V = 54-56, tail short (31-43 μm, c = 85-111, c′ = 0.6-0.8) and rounded, spicules 72-75 μm long, and four or five irregularly spaced ventromedian supplements beyond the range of the spicules. Sectonema buccociliatum sp. n. is distinguished by its 2.00-2.46 mm long body, lip region offset by constriction, 19-20 μm broad and bearing perioral cilia-like structures, odontostyle 13-14 μm long at its ventral side, 530-625 μm long neck, pharyngeal expansion occupying 62-69% of total neck length, uterus a simple tube, 116-152 μm long, pars refringens vaginae present, V = 56-62, tail short (23-31 μm, c = 72-104, c′ = 0.6-0.8) and rounded, spicules 56-68 μm long, and 3-5 spaced and weakly developed ventromedian supplements beyond the range of the spicules. Sectonema ciliatum sp. n. is characterised by its 2.79-3.13 mm long body, lip region offset by constriction, 21-22 μm broad and bearing perioral cilia-like structures, odontostyle 14-15 μm long at its ventral side, 699-722 μm long neck, pharyngeal expansion occupying 60% of total neck length, uterus a simple tube, 201-244 μm long, pars refringens vaginae present, V = 52-53, tail short (33-35 μm, c = 82-92, c′ = 0.6-0.7) and rounded, spicules 70-72 μm long, and three or four spaced and weakly developed ventromedian supplements beyond the range of the spicules. Molecular data obtained for S. ciliatum sp. n. and the derived evolutionary tree show a close phylogenetic relationship with other species of the genus.


1992 ◽  
Vol 70 (8) ◽  
pp. 1536-1540 ◽  
Author(s):  
Anthony Ricciardi ◽  
Timothy S. Wood

The freshwater bryozoan Hyalinella orbisperma (Ectoprocta: Phylactolaemata), previously known only from Michigan, is added to the list of Canadian fauna from a specimen collected at Georgian Bay, Ontario. Floatoblasts match the appearance of those described from Michigan. The sessoblast of this species is recorded and illustrated for the first time. The case for other species with sessoblasts in the genus Hyalinella is extremely weak. Scanning electron microscopy of the floatoblast and sessoblast reveals a raised reticulation with interstitial tubercles covering the capsule periblast, suggesting a close phylogenetic relationship with certain Plumatella species. It is proposed that H. orbisperma be reassigned to the genus Plumatella.


Author(s):  
Jarosław Stolarski ◽  
Ismael Coronado ◽  
Jack G. Murphy ◽  
Marcelo V. Kitahara ◽  
Katarzyna Janiszewska ◽  
...  

One of the most conserved traits in the evolution of biomineralizing organisms is the taxon-specific selection of skeletal minerals. All modern scleractinian corals are thought to produce skeletons exclusively of the calcium-carbonate polymorph aragonite. Despite strong fluctuations in ocean chemistry (notably the Mg/Ca ratio), this feature is believed to be conserved throughout the coral fossil record, spanning more than 240 million years. Only one example, the Cretaceous scleractinian coral Coelosmilia (ca. 70 to 65 Ma), is thought to have produced a calcitic skeleton. Here, we report that the modern asymbiotic scleractinian coral Paraconotrochus antarcticus living in the Southern Ocean forms a two-component carbonate skeleton, with an inner structure made of high-Mg calcite and an outer structure composed of aragonite. P. antarcticus and Cretaceous Coelosmilia skeletons share a unique microstructure indicating a close phylogenetic relationship, consistent with the early divergence of P. antarcticus within the Vacatina (i.e., Robusta) clade, estimated to have occurred in the Mesozoic (ca. 116 Mya). Scleractinian corals thus join the group of marine organisms capable of forming bimineralic structures, which requires a highly controlled biomineralization mechanism; this capability dates back at least 100 My. Due to its relatively prolonged isolation, the Southern Ocean stands out as a repository for extant marine organisms with ancient traits.


2016 ◽  
Vol 91 (2) ◽  
Author(s):  
Nicole Hackenbrack ◽  
Matthew B. Rogers ◽  
Robert E. Ashley ◽  
M. Kevin Keel ◽  
Steven V. Kubiski ◽  
...  

ABSTRACT Since the first description of adenoviruses in bats in 2006, a number of micro- and megabat species in Europe, Africa, and Asia have been shown to carry a wide diversity of adenoviruses. Here, we report on the evolutionary, biological, and structural characterization of a novel bat adenovirus (BtAdV) recovered from a Rafinesque's big-eared bat (Corynorhinus rafinesquii) in Kentucky, USA, which is the first adenovirus isolated from North American bats. This virus (BtAdV 250-A) exhibits a close phylogenetic relationship with Canine mastadenovirus A (CAdV A), as previously observed with other BtAdVs. To further investigate the relationships between BtAdVs and CAdVs, we conducted mass spectrometric analysis and single-particle cryo-electron microscopy reconstructions of the BtAdV 250-A capsid and also analyzed the in vitro host ranges of both viruses. Our results demonstrate that BtAdV 250-A represents a new mastadenovirus species that, in contrast to CAdV, has a unique capsid morphology that contains more prominent extensions of protein IX and can replicate efficiently in a phylogenetically diverse range of species. These findings, in addition to the recognition that both the genetic diversity of BtAdVs and the number of different bat species from disparate geographic regions infected with BtAdVs appears to be extensive, tentatively suggest that bats may have served as a potential reservoir for the cross-species transfer of adenoviruses to other hosts, as theorized for CAdV. IMPORTANCE Although many adenoviruses are host specific and likely codiverged with their hosts over millions of years, other adenoviruses appear to have emerged through successful cross-species transmission events on more recent time scales. The wide geographic distribution and genetic diversity of adenoviruses in bats and their close phylogenetic relationship to Canine mastadenovirus A (CAdV A) has raised important questions about how CAdV A, and possibly other mammalian adenoviruses, may have emerged. Although most adenoviruses tend to cause limited disease in their natural hosts, CAdV A is unusual in that it may cause high morbidity and sometimes fatal infections in immunocompetent hosts and is thus an important pathogen of carnivores. Here, we performed a comparative evolutionary and structural study of representative bat and canine adenoviruses to better understand the relationship between these two viral groups.


2006 ◽  
Vol 84 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Wendy A. Untereiner ◽  
Françoise A. Naveau ◽  
Jason Bachewich ◽  
Andrea Angus

During an investigation of lignicolous ascomycetes from Luxembourg, we isolated a Phialophora -like species that produced striking red colonies. To confirm the identity of this fungus as Catenulifera rhodogena , we compared it with isolates of Catenulifera rhodogena and Hyphodiscus hymeniophilus on a variety of media. Portions of the β-tubulin gene and the nuclear ribosomal DNA cistron (internal transcribed spacers (ITS) and large subunit (LSU)) were sequenced to examine the relationship of isolates of Catenulifera rhodogena and Hyphodiscus hymeniophilus from different substrates and to test the hypothesis that Cadophora and Catenulifera are congeneric. The phylogenetic position of Catenulifera within the Ascomycota was investigated based on the analysis of the small-subunit (SSU) rDNA sequences. The isolates examined were indistinguishable micromorphologically and closely related phylogenetically. Three strains of Catenulifera rhodogena from bark or wood and one strain from Piptoporus betulinus formed a strongly supported clade in analyses of β-tubulin and ITS sequences. This clade did not encompass the ex-type isolates of Cistella rubescens and Scopulariopsis rhodogena or a second isolate of Catenulifera rhodogena from Piptoporus betulinus. Analysis of partial LSU sequences confirmed the close phylogenetic relationship of Catenulifera rhodogena and Hyphodiscus hymeniophilus but provided no evidence that the isolates could be grouped by substrate or that Catenulifera is synonymous with Cadophora. The position of Catenulifera within the Helotiales was not resolved based on the comparison of LSU and SSU sequences, but the isolate for which we obtained complete SSU sequence grouped with the root endophyte Phialocephala fortinii. Comparison of ITS sequences confirmed the close phylogenetic relationship of Hyphodiscus to members of the Dermateaceae and Hyaloscyphaceae.


2010 ◽  
Vol 24 (1) ◽  
pp. 23 ◽  
Author(s):  
Sergio Vargas ◽  
Michael Eitel ◽  
Odalisca Breedy ◽  
Bernd Schierwater

Several studies attempting to clarify the taxonomy and systematics of Octocorallia have highlighted the important role of molecular characters in corroborating or rejecting previous hypotheses based on morphological variation. One such hypothesis is that of a close phylogenetic relationship between the genera Lytreia, Bebryce and Heterogorgia proposed by Bayer based on morphological studies of the genera. Herein, we tested Bayer’s hypothesis using the mitochondrial marker mshI. We deduced a molecular phylogeny including members of the families Gorgoniidae and ‘Paramuriceidae’ that corroborated the existence of Bayer’s Lytreia–Bebryce–Heterogorgia clade. In addition, we provide a morphological assessment of the three genera as well as diagnoses for each of them. We also discuss, based on the phylogenetic results obtained, the evolution of sclerite morphology within Bayer’s Lytreia–Bebyce–Heterogorgia clade. Finally, we propose a Tethyan origin for the Lytreia–Bebryce–Heterogorgia clade.


1982 ◽  
Vol 131 (3) ◽  
pp. 287-290 ◽  
Author(s):  
Elke Seewaldt ◽  
Karl-Heinz Schleifer ◽  
Eberhard Bock ◽  
Erko Stackebrandt

2019 ◽  
Author(s):  
Adriano de Bernardi Schneider ◽  
Denis Jacob Machado ◽  
Daniel Janies

The ongoing and severe public health threat of viruses of the family Flaviviridae, including dengue, hepatitis C, West Nile, yellow fever, and zika, demand a greater understanding of how these viruses evolve, emerge and spread in order to respond. Central to this understanding is an updated phylogeny of the entire family. Unfortunately, most cladograms of Flaviviridae focus on specific lineages, ignore outgroups, and rely on midpoint rooting, hampering their ability to test ingroup monophyly and estimate ingroup relationships. This problem is partly due to the lack of fully annotated genomes of Flaviviridae, which has genera with slightly different gene content, hindering genome analysis without partitioning. To tackle these problems, we developed an annotation pipeline for Flaviviridae that uses a combination of ab initio and homology-based strategies. The pipeline recovered 100% of the genes in reference genomes and annotated over 97% of the expected genes in the remaining non curated sequences. We further demonstrate that the combined analysis of genomes of all genera of Flaviviridae (Flavivirus, Hepacivirus, Pegivirus, and Pestivirus), as made possible by our annotation strategy, enhances the phylogenetic analyses of these viruses for all optimality criteria that we tested (parsimony, maximum likelihood, and posterior probability). The final tree sheds light on the phylogenetic relationship of viruses that are divergent from most Flaviviridae and should be reclassified, especially the soybean cyst nematode virus 5 (SbCNV-5) and the Tamana bat virus. We also corroborate the close phylogenetic relationship of dengue and zika viruses with an unprecedented degree of support.


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