Search results for " RNA"
showing 10 items of 1405 documents
PCR Typing of Alu Elements — Molecular Genetics and Forensic Application
1996
Alu repeats belong to the family of short interspersed elements (SINEs) and are among the most abundant repetitive DNA sequences in the mammalian genome. They represent mobile genetic elements ancestrally derived from the 7SL RNA gene and have presumably spread within the genome by retroposition (reviewed in [1]). A particular group of Alu repeats appears to be human-specific (HS subfamily) and has expanded only recently within the human genome as indicated by distinct dimorphisms at various loci due to the presence or absence of an Alu repeat. In recent extensive studies, the frequency distributions of Alu insertions at selected loci in various human racial groups and populations were dete…
Phylogenetic relationships within the family Halomonadaceae based on comparative 23S and 16S rRNA gene sequence analysis.
2010
A phylogenetic study of the family Halomonadaceae was carried out based on complete 16S rRNA and 23S rRNA gene sequences. Several 16S rRNA genes of type strains were resequenced, and 28 new sequences of the 23S rRNA gene were obtained. Currently, the family includes nine genera (Carnimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola and Zymobacter). These genera are phylogenetically coherent except Halomonas, which is polyphyletic. This genus comprises two clearly distinguished clusters: group 1 includes Halomonas elongata (the type species) and the species Halomonas eurihalina, H. caseinilytica, H. halmophila, H. sabkhae, H. almeriensis, H. hal…
Other astacin homologs
2013
Publisher Summary This chapter describes the activity, specificity and structural chemistry of astacin homologs. The astacins are members of the metzincin superfamily such as the serralysins, the reprolysins/adamalysins, the matrixins, the leishmanolysins, the pregnancy-associated plasma proteins, the snapalysins and the fragilysins. Proteins of the hatching subfamily have been shown to be important for the cleavage of membranes coating developing embryos of invertebrates and vertebrates. Other members of this subfamily have varying or even several functions. UVS.2 from Xenopus, originally shown to play a role in dorso-anterior development, has been identified as the frog hatching enzyme. T…
Genomics and the gene transcription kinetics in yeast.
2007
As an adaptive response to new conditions, mRNA concentrations in eukaryotes are readjusted after any environmental change. Although mRNA concentrations can be modified by altering synthesis and/or degradation rates, the rapidity of the transition to a new concentration depends on the regulation of mRNA stability. There are several plausible transcriptional strategies following environmental change, reflecting different degrees of compromise between speed of response and cost of synthesis. The recent development of genomic techniques now enables researchers to determine simultaneously (either directly or indirectly) the transcription rates and mRNA half-lifes, together with mRNA concentrati…
<em>In vitro</em> tRNA Methylation Assay with the <em>Entamoeba histolytica</em> DNA and tRNA Methyltransferase Dnmt2 (Ehmeth…
2010
Protozoan parasites are among the most devastating infectious agents of humans responsible for a variety of diseases including amebiasis, which is one of the three most common causes of death from parasitic disease. The agent of amebiasis is the amoeba parasite Entamoeba histolytica that exists under two stages: the infective cyst found in food or water and the invasive trophozoite living in the intestine. The clinical manifestations of amebiasis range from being asymptomatic to colitis, dysentery or liver abscesses. E. histolytica is one of the rare unicellular parasite with 5-methylcytosine (5mC) in its genome. 1, 2 It contains a single DNA methyltransferase, Ehmeth, that belongs to the D…
Murine Cytomegalovirus Major Immediate-Early Enhancer Region Operating as a Genetic Switch in Bidirectional Gene Pair Transcription
2007
ABSTRACT Enhancers are defined as DNA elements that increase transcription when placed in any orientation relative to a promoter. The major immediate-early (MIE) enhancer region of murine cytomegalovirus is flanked by transcription units ie1/3 and ie2 , which are transcribed in opposite directions. We have addressed the fundamental mechanistic question of whether the enhancer synchronizes transcription of the bidirectional gene pair (synchronizer model) or whether it operates as a genetic switch, enhancing transcription of either gene in a stochastic alternation (switch model). Clonal analysis of cytokine-triggered, transcription factor-mediated MIE gene expression from latent viral genomes…
Dissemination of wine-related yeasts by migratory birds
2011
Summary The present work was undertaken to evaluate the contribution of migratory birds in the environmental dissemination of yeasts. Four sites (Mazara del Vallo, Lampedusa, Ustica and Linosa), representing the main stop-over points in Sicily, were analysed during spring and autumnal bird migration and 349 birds (belonging to 10 families) were ringed and analysed for yeast presence. A total of 125 yeasts were isolated and identified by a multiple genotypic approach, consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 18 species, including the technological rele…
12S rRNA mitochondrial gene as marker to trace Sicilian mono-species dairy products
2016
Abstract For a rapid, specific and sensitive identification of cows', ewes' and goats' milk in mono-species Sicilian dairy products, species-specific duplex-PCR protocol was applied. DNA samples from blood and experimental cheeses of Sicilian autochthonous breeds were extracted to amplify the 12S rRNA (and part of 16S rRNA in case of Ovis aries ) mitochondrial species-specific gene fragment. The use of species-specific primers for Bos taurus , Capra hircus and Ovis aries species, after electrophoresis on agarose gel, yielded fragments of 256 bp, 326 bp and 172 bp, respectively. Amplification by duplex - PCR of DNA pools from two species showed detection thresholds of 0.1% of “contaminant” D…
Nucleotide sequence of a Trichophyton mentagrophytes HindIII mitochondrial DNA fragment containing at RNA gene cluster
1993
A 0.85-kb HindIII mitochondrial DNA fragment of the dermatophytic fungus Trichophyton mentagrophytes has been sequenced. The fragment contains eight complete genes which corresponds to a tRNA gene cluster. From 5′ to 3′, the sequenced genes code for tRNAthr, tRNAglu, tRNAval, tRNAmet1, tRNAmet3, tRNAleu, tRNAala, and tRNAphe. This tRNA gene cluster is located downstream of the larger ribosomal RNA gene. The particularities ofthe sequenced genes and their comparison with other fungal tRNA mitochondrial genes are reported.
The cost of replication fidelity in an RNA virus
2005
It is often argued that high mutation rates are advantageous for RNA viruses, because they confer elevated rates of adaptation. However, there is no direct evidence showing a positive correlation between mutation and adaptation rates among RNA viruses. Moreover, theoretical work does not argue in favor of this prediction. We used a series of vesicular stomatitis virus clones harboring single amino acid substitutions in the RNA polymerase to demonstrate that changes inducing enhanced fidelity paid a fitness cost, but that there was no positive correlation between mutation an adaptation rates. We demonstrate that the observed mutation rate in vesicular stomatitis virus can be explained by a t…