Search results for " DNA"
showing 10 items of 2475 documents
Assessing the root of bilaterian animals with scalable phylogenomic methods.
2009
A clear picture of animal relationships is a prerequisite to understand how the morphological and ecological diversity of animals evolved over time. Among others, the placement of the acoelomorph flatworms, Acoela and Nemertodermatida, has fundamental implications for the origin and evolution of various animal organ systems. Their position, however, has been inconsistent in phylogenetic studies using one or several genes. Furthermore, Acoela has been among the least stable taxa in recent animal phylogenomic analyses, which simultaneously examine many genes from many species, while Nemertodermatida has not been sampled in any phylogenomic study. New sequence data are presented here from org…
Expression of the human XPB/ERCC-3 excision repair gene-homolog in the sponge Geodia cydonium after exposure to ultraviolet radiation.
1998
Abstract The marine demosponge Geodia cydonium encodes a gene, termed GCXPB , which displays 62% identity to the human XPB/ERCC-3 gene that specifically corrects the repair defect in xeroderma pigmentosum and in Cockayne's syndrome. The cDNA was isolated and characterized the deduced aa sequence, XPB_GEOCY, with the calculated size of 91,541 Da comprises the characteristic domains found in the related helicases. Phylogenetic tree analysis revealed that the sponge sequence is grouped to the metazoan related XPB/ERCC-3 polypeptides. Northern Blot analyses have been performed with sponge samples collected at different depths, thus exposed to different intensities of UV sunlight in the field. T…
RNA dependent DNA polymerase in cells of xeroderma pigmentosum
1971
Abstract Cells from X.P. ∗ skin contain an RNA dependent DNA polymerase, while in cells from normal skin this enzyme is lacking. This finding stimulates the thought that carcinogenesis in X.P. cells is due to an infection with an oncogenic RNA virus.
Polymorphisms in DNA repair genes modulate survival in cisplatin/gemcitabine-treated non-small-cell lung cancer patients.
2006
Abstract Background: Impaired DNA repair capacity may favorably affect survival in cisplatin/gemcitabine-treated non-small-cell lung cancer (NSCLC) patients. We investigated the association of survival with genetic polymorphisms in X-ray repair cross-complementing group 1 and group 3 (XRCC3), xeroderma pigmentosum group D (XPD), excision repair cross-complementing group 1, ligase IV, ribonucleotide reductase, TP53, cyclooxygenase-2, interleukin-6, peroxisome proliferator-activated receptor γ, epidermal growth factor, methylene-tetra-hydrofolate reductase and methionine synthase. Patients and methods: One hundred and thirty-five stage IV or IIIB (with malignant pleural effusion) NSCLC patien…
Modeling hexanal production in oxido-reducing conditions by the yeast Yarrowia lipolytica
2009
International audience; Hexanal produced by cells of a recombinant Yarrowia lipolytica yeast expressing the hydroperoxide lyase (HPL) from green bell pepper fruit was studied under oxido-reducing conditions using the reducing dithiotreitol and oxidizing potassium ferricyanide compounds. The combined effect of pH, linoleic acid 13-hydroperoxides concentration, temperature and oxido-reducing molecules on the hexanal production was studied. Significant positive effects for the hexanal production were found using high concentrations of hydroperoxides (100 mM, 30 g/L). Adding reducing molecules enhanced significantly hexanal production while the oxidizing molecules had an inhibitory effect. Comb…
Distinct Clones of Yersinia pestis Caused the Black Death
2010
From AD 1347 to AD 1353, the Black Death killed tens of millions of people in Europe, leaving misery and devastation in its wake, with successive epidemics ravaging the continent until the 18th century. The etiology of this disease has remained highly controversial, ranging from claims based on genetics and the historical descriptions of symptoms that it was caused by Yersinia pestis to conclusions that it must have been caused by other pathogens. It has also been disputed whether plague had the same etiology in northern and southern Europe. Here we identified DNA and protein signatures specific for Y. pestis in human skeletons from mass graves in northern, central and southern Europe that …
Application of an inexpensive and high-throughput genomic DNA extraction method for the molecular ecology of zooplanktonic diapausing eggs
2008
We describe the application of a simple, low-cost, and effective method of DNA extraction (hot sodium hydroxide and Tris, HotSHOT) to the diapausing propagules of continental aquatic invertebrates for its use in PCR amplification. We illustrate the use of the technique in cladocerans, rotifers, anostracans, notostracans, and copepod diapausing eggs. We compare the performance of the HotSHOT technique to the currently most widely used method for DNA extraction of zooplankton eggs and individuals, the chelating resin (or Chelex) technique. The HotSHOT technique overcomes several of the problems posed by Chelex and permits easy optimization for its use with 96-well plates for high-throughput D…
Inter-laboratory evaluation of the ISO standard 11063 "Soil quality -- Method to directly extract DNA from soil samples"
2011
International audience; Extracting DNA directly from micro-organisms living in soil is a crucial step for the molecular analysis of soil microbial communities. However, the use of a plethora of different soil DNA extraction protocols, each with its own bias, makes accurate data comparison difficult. To overcome this problem, a method for soil DNA extraction was proposed to the International Organization for Standardization (ISO) in 2006. This method was evaluated by 13 independent European laboratories actively participating in national and international ring tests. The reproducibility of the standardized method for molecular analyses was evaluated by comparing the amount of DNA extracted, …
Seasonal fluctuations and long-term persistence of pathogenic populations of Agrobacterium spp. in soils.
2002
ABSTRACT Short- and long-term persistence of pathogenic (i.e., tumor forming) agrobacteria in soil was investigated in six nursery plots with a history of high crown gall incidence. No pathogenic Agrobacterium strains were isolated in soil samples taken in fall and winter in any plots, but such strains were isolated from both bulk soils and weed rhizospheres (over 0.5 × 10 5 pathogenic CFU/g of bulk soil or rhizosphere) in three out of six plots in spring and summer. PCR amplifications of a vir sequence from DNA extracted from soil confirmed the presence of Ti plasmids in summer and their absence in fall and winter. The results indicate that strains that harbor a Ti plasmid had an unforesee…
Acyl-homoserine lactone production is more common among plant-associated Pseudomonas spp. than among soilborne Pseudomonas spp.
2001
ABSTRACT A total of 137 soilborne and plant-associated bacterial strains belonging to different Pseudomonas species were tested for their ability to synthesize N -acyl-homoserine lactones (NAHL). Fifty-four strains synthesized NAHL. Interestingly, NAHL production appears to be more common among plant-associated than among soilborne Pseudomonas spp. Indeed, 40% of the analyzed Pseudomonas syringae strains produced NAHL which were identified most often as the short-chain NAHL, N -hexanoyl- l -homoserine lactone, N -(3-oxo-hexanoyl)-homoserine lactone, and N -(3-oxo-octanoyl)- l -homoserine lactone (no absolute correlation between genomospecies of P. syringae and their ability to produce NAHL …