Search results for "PHYLOGENE"
showing 10 items of 1189 documents
Taxas de substituições das Annonaceas: uma perspectiva do modelo códon
2014
The Annonaceae includes cultivated species of economic interest and represents an important source of information for better understanding the evolution of tropical rainforests. In phylogenetic analyses of DNA sequence data that are used to address evolutionary questions, it is imperative to use appropriate statistical models. Annonaceae are cases in point: Two sister clades, the subfamilies Annonoideae and Malmeoideae, contain the majority of Annonaceae species diversity. The Annonoideae generally show a greater degree of sequence divergence compared to the Malmeoideae, resulting in stark differences in branch lengths in phylogenetic trees. Uncertainty in how to interpret and analyse these…
The migratory birds: novel ecological niche of fungal diversity?
2015
Francesca et al (2010) studied the ecology of wine yeasts associated to birds caught in vineyards. The same authors were able to prove that migratory birds might carry living pro-technological yeasts for about 12 hours from the ingestion of inoculated feed (Francesca et al 2012). In subsequent studies, they tried to demonstrate that microorganisms are not only transported for a short period by birds, but microorganisms might be adapted to the specific conditions (body temperature about 42 °C and low pH) of the intestinal tract of birds. Hence, it was demonstrated that the majority of isolates carried by birds are thermotolerant. The most interesting results were the isolation of two new spe…
Better the devil you know? Guidelines for insightful utilization of nrDNA ITS in species-level evolutionary studies in plants.
2006
The internal transcribed spacers (ITS) of the nuclear ribosomal 18S–5.8S–26S cistron continue to be the most popular non-plastid region for species-level phylogenetic studies of plant groups despite the early warnings about their potential Xaws, which may ultimately result in incorrect assumptions of orthology. It has been gradually realized that the alternative target regions in the nuclear genome (lowcopy nuclear genes, LCNG) are burdened with similar problems. The consequence is that, to date, developing useful LCNG for nonmodel organisms requires an investment in time and eVort that hinders its use as a real practical alternative for many labs. It is here argued that ITS sequences, desp…
Bermanella marisrubri gen. nov., sp. nov., a genome-sequenced gammaproteobacterium from the Red Sea
2009
5 pages, 2 figures, 1 table
Acyl Transferase Domains of Putative Polyketide Synthase (PKS) Genes in Aspergillus and Penicillium Producers of Ochratoxin A and the Evaluation of P…
2009
Fungal polyketide synthases (PKS) are responsible for the biosynthesis of several mycotoxins and other secondary metabolites. PKS genes in ochratoxin producing species from Aspergillus and Penicillum genera have been identified using a degenerate primer pair developed for the acyl transferase (AT) domain of fungal PKSs. Sequences of AT domains were aligned and analyzed using phylogenetic methods. The AT domain sequences appeared to be specific for a particular type of fungal PKSs and were related to PKSs involved in different mycotoxin biosynthesis pathways, including ochratoxin A. We have also developed primers suitable for amplifying AT domain sequences in strains belonging to the A. nig…
Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of…
2009
This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species …
Molecular evidence for phylogenetic relationships among buntings and American sparrows (Emberizidae)
2001
To help clarify controversial phylogenetic relationships within the family Emberizidae, we sequenced 1238 bp of mitochondrial DNA from the cytochrome b gene and a flanking portion of ND5. Although the longspurs (Calcarius) and the snow buntings (Plectrophenax) have been grouped with the Old World buntings (Emberiza) in traditional classifications, our molecular phylogenies constructed with maximum likelihood and maximum parsimony place these general basal to a clade in which the Old World buntings and North American sparrows are sister groups. Contrary to the hypothesis that the radiation within Emberiza is recent following a westward expansion of emberizid stock into Eurasia from North Ame…
Molecular Characterization of the Leucine Plasmid from Buchnera aphidicola , Primary Endosymbiont of the Aphid Acyrthosiphon pisum
2000
The complete sequence of the leucine plasmid of Buchnera aphidicola from the aphid Acyrthosiphon pisum (pLeu-BAp) is reported. Its gene organization was concordant with those of other leucine plasmids of Buchnera from aphids of the Aphidini and Macrosiphini tribes. Three inverted repeats are present in pLeu-BAp. Two of them are also present in pLeu from the family Aphididae: (i) SIR1, located downstream the leucine operon, resembles a rho-independent terminator of transcription, and (ii) LIR1, located upstream of the leucine operon, is suggested to be involved in transcription termination or messenger stability. The third, located near the putative ATGC repeats involved in the origin of rep…
Phylogeny and morphology of Hirsutella tunicata sp. nov. (Ophiocordycipitaceae), a novel mite parasite from Peru
2013
Abstract A new species of Hirsutella was isolated from unidentified mites on Petri plates inoculated with soil and root fragments collected from asparagus rhizosphere at Viru, Northern Peru. The fungus differs from other Hirsutella species by an envelope surrounding the conidium, conidia dimension and DNA sequences. In PDA cultures, the mycelium produced aerial hyphae with conidiogenous cells mainly at right angles, occasionally showing a secondary conidiophore. The solitary conidia are cymbiform, slightly apiculate, 5.0–6.0 × 3.0–4.0 μm. Phylogenetic analyses with partial rRNA and β-tubulin gene sequences confirmed the fungus as an Hirsutella (Ophiocordycipitaceae). Closest species shown b…
Hundreds of nuclear and plastid loci yield novel insights into orchid relationships.
2021
Pérez-Escobar, Oscar Alejandro, Dodsworth, Steven, Bogarín, Diego, Bellot, Sidonie, Balbuena, Juan A, Schley, Rowan J, Kikuchi, Izai A, Morris, Sarah K, Epitawalage, Niroshini, Cowan, Robyn, Maurin, Olivier, Zuntini, Alexandre, Arias, Tatiana, Serna-Sánchez, Alejandra, Gravendeel, Barbara, Torres Jimenez, Maria Fernanda, Nargar, Katharina, Chomicki, Guillaume, Chase, Mark W, Leitch, Ilia J, Forest, Félix, Baker, William J (2021): Hundreds of nuclear and plastid loci yield novel insights into orchid relationships. American journal of botany 108 (7): 1166-1180, DOI: http://doi.org/10.5281/zenodo.7778176