Search results for "phylogeny"
showing 10 items of 1398 documents
Ultrastructure of posterior sternal glands of Macrotermes annandalei (Silvestri): new members of the sexual glandular set found in termites (Insecta).
2004
In female alates of Macrotermes annandalei, two types of abdominal glands are involved in the secretion of sex pheromone. Tergal glands are found at the anterior margin of tergites 6-10 and posterior sternal glands (PSGs) are located at the anterior margin of sternites 6-7. The cytological features of both types of glands are quite similar. The fine structural organization of PSGs is studied more precisely and described for the first time. The glandular cuticle is pitted with narrow apertures corresponding to the openings of numerous subcuticular pouches. Several Class 3 glandular units open in each pouch. One canal cell and one secretory cell make an individual glandular unit. The canal ce…
Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.
2011
Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1) strong founder effects due to rapidly growing populations and very large population sizes, and (2) the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of…
Phylogeny and Mycotoxin Characterization of Alternaria Species Isolated from Wheat Grown in Tuscany, Italy
2018
Wheat, the main source of carbohydrates worldwide, can be attacked by a wide number of phytopathogenic fungi, included Alternaria species. Alternaria species commonly occur on wheat worldwide and produce several mycotoxins such as tenuazonic acid (TA), alternariol (AOH), alternariol-monomethyl ether (AME), and altenuene (ALT), provided of haemato-toxic, genotoxic, and mutagenic activities. The contamination by Alternaria species of wheat kernels, collected in Tuscany, Italy, from 2013 to 2016, was evaluated. Alternaria contamination was detected in 93 out of 100 field samples, with values ranging between 1 and 73% (mean of 18%). Selected strains were genetically characterized by multi-locus…
Diagnosis of flavobacteriosis by direct amplification of rRNA genes
2002
A broad-range bacterial PCR method with universal 16S rDNA targeting primers and bacterial cultivation was used to identify the putative pathogen in flavobacterial outbreaks. Restriction fragment length polymorphism (PCR-RFLP) analysis and sequencing of the partial 16S rDNA PCR products of 10 skin samples and 10 representative isolates derived from the same fish specimens revealed differences between direct molecular and cultivation-based analysis. Flavobacterium columnare-like sequences dominated in the direct molecular analysis in most cases, whereas most of the isolates belonged to a phylogenetically heterogeneous group of flavobacteria clustering with F. hibernum. F. columnare was isola…
Species-specific identification of Dekkera/Brettanomyces yeasts by fluorescently labeled DNA probes targeting the 26S rRNA.
2007
Sequencing of the complete 26S rRNA genes of all Dekkera/Brettanomyces species colonizing different beverages revealed the potential for a specific primer and probe design to support diagnostic PCR approaches and FISH. By analysis of the complete 26S rRNA genes of all five currently known Dekkera/Brettanomyces species (Dekkera bruxellensis, D. anomala, Brettanomyces custersianus, B. nanus and B. naardenensis), several regions with high nucleotide sequence variability yet distinct from the D1/D2 domains were identified. FISH species-specific probes targeting the 26S rRNA gene's most variable regions were designed. Accessibility of probe targets for hybridization was facilitated by the constr…
The sequencing of the complete genome of a Tomato black ring virus (TBRV) and of the RNA2 of three Grapevine chrome mosaic virus (GCMV) isolates from…
2014
The complete genome of a Tomato black ring virus isolate (TBRV-Mirs) (RNA1, 7,366 nt and RNA2, 4,640 nt) and the RNA2 sequences (4,437; 4,445; and 4,442 nts) of three Grapevine chrome mosaic virus isolates (GCMV-H6, -H15, and -H27) were determined. All RNAs contained a single open reading frame encoding polyproteins of 254 kDa (p1) and 149 kDa (p2) for TBRV-Mirs RNA1 and RNA2, respectively, and 146 kDa for GCMV RNA2. p1 of TBRV-Mirs showed the highest identity with TBRV-MJ (94 %), Beet ringspot virus (BRSV, 82 %), and Grapevine Anatolian ringspot virus (GARSV, 66 %), while p2 showed the highest identity with TBRV isolates MJ (89 %) and ED (85 %), followed by BRSV (65 %), GCMV (58 %), and GA…
Phylogenetic relationship of ubiquitin repeats in the polyubiquitin gene from the marine sponge Geodia cydonium
1994
Ubiquitin is a 76-residue protein which is highly conserved among eukaryotes. Sponge (Porifera) ubiquitin, isolated from Geodia cydonium, is encoded by a gene (termed GCUBI) with six repeats, GCUBI-1 to GCUBI-6. All repeat units encode the same protein (with one exception: GCUBI-4 encodes ubiquitin with a change of Leu to Val at position 71). On the nt level the sequences of the six repeats differ considerably. All changes (except in GCUBI-4) are silent substitutions, which do not affect the protein structure. However, there is one major difference between the repeats: Codons from both codon families (TCN and AGPy) are simultaneously used for the serine at position 65. Using this characteri…
Analysis of the Overdispersed Clock in the Short-Term Evolution of Hepatitis C Virus: Using the E1/E2 Gene Sequences to Infer Infection Dates in a Si…
2006
Abstract The assumption of a molecular clock for dating events from sequence information is often frustrated by the presence of heterogeneity among evolutionary rates due, among other factors, to positively selected sites. In this work, our goal is to explore methods to estimate infection dates from sequence analysis. One such method, based on site stripping for clock detection, was proposed to unravel the clocklike molecular evolution in sequences showing high variability of evolutionary rates and in the presence of positive selection. Other alternatives imply accommodating heterogeneity in evolutionary rates at various levels, without eliminating any information from the data. Here we pre…
Enterovirus Co-infections and Onychomadesis after Hand, Foot, and Mouth Disease, Spain, 2008
2011
Mixed infection of enteroviruses may explain the rare complication of nail shedding. Onychomadesis after HFMD
Nucleotide variation in the VP7 gene affects PCR genotyping of G9 rotaviruses identified in Italy
2003
A modified (aFT9m) and a degenerate (aFT9d) version of the rotavirus G9-specific primer (aFT9) allowed strains that were previously untypable, because of point mutations accumulating at the primer binding site, to be G typed by reverse transcription-polymerase chain reaction. The strains were collected during 2001-2002 in Italy in hospitals of the Apulia region, from children affected by severe rotavirus-associated enteritis. Using a wide selection of G9 rotaviruses detected worldwide, sequencing of the G9 untypable strains, sequence comparison, and phylogenetic analysis showed that the Italian strains have strong genetic similarity (< or =99.4%) to G9 rotaviruses identified recently in man…