Search results for "Phylogenetics"
showing 10 items of 777 documents
Two new species of the genus Ochroconis, O. lascauxensis and O. anomala isolated from black stains in Lascaux Cave, France
2012
In the year 2001, some conspicuous black stains appeared on the walls of Lascaux Cave in France, which progressively disseminated throughout the cave. These black stains were so evident by 2007 that they have become one of the cave's major problems. In a mycological study of the black stains, Ochroconis strains were abundant among the isolates and constituted the major group of melanised fungi. Two new species of the genus Ochroconis, O. lascauxensis and O. anomala, were isolated and described. The description is based on the morphology of the fungi and the phylogenetic relationships of two of its gene regions internal transcribed spacer (ITS) and RNA polymerase II subunit B (RPB2). In addi…
PCR survey ofXenoturbella bockiHox genes
2007
Xenoturbella bocki has recently been identified as one of the most basal deuterostomes, although an even more basal phylogenetic position cannot be ruled out. Here we report on a polymerase chain reaction survey of partial Hox homeobox sequences of X. bocki. Surprisingly, we did not find evidence for more than five Hox genes, one clear labial/PG1 ortholog, one posterior gene most similar to the PG9/10 genes of Ambulacraria, and three central group genes whose precise assignment to a specific paralog group remains open. We furthermore report on a re-evaluation of the available published evidence of Hox genes in other basal deuterostomes.
Globin genes are present in Ciona intestinalis.
2003
The key position of the Ciona intestinalis basal to the vertebrate phylogenetic tree brings up the question of which respiratory proteins are used by the tunicate to facilitate oxygen transport and storage. The publication of the Ciona draft genome sequence suggests that globin genes are completely missing and that-like some molluscs and arthropods-the sea squirt uses hemocyanin instead of hemoglobin for respiration. However, we report here the presence and expression of at least four distinct globin gene/protein sequences in Ciona. This finding is in agreement with the ancestral phylogeny of the vertebrate globins. Moreover, it seems likely that the Ciona hemocyanin-like sequences have enz…
Phylogeny of snapdragon species (Antirrhinum; Scrophulariaceae) using non-coding cpDNA sequences
2005
Antirrhinum is an Old World genus of up to 25 perennial taxa, mainly located in the western Mediterranean basin. A molecular analysis of 24 taxa of Antirrhinum was undertaken using cpDNA sequences from the trnT (UGU)-trnL (UAA) 5' exon region. The Kimura two-parameter model was chosen to calculate pairwise nucleotide divergence values between cpDNA sequences, and a bootstrapped neighbor-joining dendrogram was constructed from the nucleotide divergence distance matrix. Eighteen sites were variable across the studied samples and the position of 7 indels, ranging from 1 to 7 bp, was inferred from the sequence alignment. Several trnT-trnL sequences are identical in: some members of subsection K…
The monophyly and evolution of Cynara L. (Asteraceae) sensu lato: evidence from the Internal Transcribed Spacer region of nrDNA
2005
The monophyly and evolution of Cynara was investigated using ITS sequence data. Parsimony analysis supports the monophyly of Cynara sensu lato, i.e. including the distinctive taxa C. humilis and C. tournefortii. This contradicts the recent decision to create a new monotypic genus Arcyna for C. tournefortii. A hypothesised close relationship between C. tournefortii and Silybum Adans. is also refuted. Four of the five species of Cynara, for which multiple accessions were sequenced, were shown to be monophyletic but C. baetica was found to be non-monophyletic. Free energy estimates for ITS1 secondary structure and conservation of the 5.8S region suggest that this is not due to the occurrence o…
Robinia aurata n. g., n. sp. (Digenea: Hemiuridae) from the mugilid Liza aurata with a molecular confirmation of its position within the Hemiuroidea.
2006
Robinia aurata n. g., n. sp. is described from Liza aurata (Mugilidae), the golden grey mullet, from the Ebro Delta, Spanish Mediterranean. The new genus differs from all other hemiurid genera in the combined possession of muscular flanges and a vestigial ecsoma. Within the Bunocotylinae, which currently accommodates 2 genera, Bunocotyle and Saturnius, the new genus exhibits a unique combination of blind caeca, Juel's organ, post-ovarian bulk of the uterus in the hind-body, and tegumental papillae surrounding the oral and ventral sucker apertures. Furthermore, Robinia n. g. differs from both Bunocotyle and Saturnius in the nature of the muscular extensions around the oral sucker, with the s…
Sinophysis and Pseudophalacroma are Distantly Related to Typical Dinophysoid Dinoflagellates (Dinophysales, Dinophyceae)
2011
Dinophysoid dinoflagellates are usually considered a large monophyletic group. Large subunit and small subunit (SSU) rDNA phylogenies suggest a basal position for Amphisoleniaceae (Amphisolenia,Triposolenia) with respect to two sister groups, one containing most Phalacroma species plus Oxyphysis and the other Dinophysis,Ornithocercus, Dinophysoid dinoflagellates are usually considered a large monophyletic group. Large subunit and small subunit (SSU) rDNA phylogenies suggest a basal position for Amphisoleniaceae (Amphisolenia,Triposolenia) with respect to two sister groups, one containing most Phalacroma species plus Oxyphysis and the other Dinophysis,Ornithocercus, Histioneis,Citharistes an…
Complete phylogeny and historical biogeography of true rosefinches (Aves:Carpodacus)
2013
True rosefinches (Aves: Carpodacus) are restricted to Eurasia, and 19 out of 25 species occur in the Sino-Himalayas, making this the likely centre of origin. To test this hypothesis, suggested species splits had to be evaluated and potential further cryptic diversity unravelled. A taxon-complete dated molecular phylogeny was reconstructed using maximum-likelihood and Bayesian methods. Maximum-parsimony and likelihood approaches were applied to deduce ancestral areas. Rosefinches, including the widespread Carpodacus erythrinus (Pallas, 1770), originated in south-west China (and the Himalayas) 14 Mya, and gave rise to a smaller clade consisting of C. erythrinus, Haematospiza sipahi (Hodgson, …
Characterization of Lactobacillus isolates from fermented olives and their bacteriocin gene profiles
2011
Near one hundred isolates of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum from table olives were studied. Strains were genotyped by rep-PCR. Although the technique failed to differentiate some isolates at the species level, it proved a robust and easy procedure that could be useful for distinguishing between related strains of L. paraplantarum, L. pentosus and L. plantarum from a large pool of unrelated strains of these species. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnB, plnC, plnD, plnE/F, plnF, plnI, plnJ, plnK, plnG and plnN in most isolates of the three species. Sequences of bacteriocin genes present in L.…
The comparison of beta-thymosin homologues among metazoa supports an arthropod-nematode clade.
2000
The definition of an Ecdysozoa clade among the protostomians, including all phyla with a regularly molted alpha-chitin-rich cuticle, has been one of the most provocative hypotheses to arise from recent investigations on animal phylogeny. Here we present evidence in favor of an arthropod-nematode clade, from the comparison of beta-thymosin homologues among the Metazoa. Arthropods and nematodes share the absence of the highly conserved beta-thymosin form found in all other documented bilaterian phyla as well as sponges, and the possession of a very unusual, internally triplicated homologue of the beta-thymosin protein, unknown in other phyla. We argue that such discrete molecular character is…