Search results for "Genome"
showing 10 items of 1913 documents
The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants
2008
We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The …
Nucleotide excision repair of abasic DNA lesions
2019
AbstractApurinic/apyrimidinic (AP) sites are a class of highly mutagenic and toxic DNA lesions arising in the genome from a number of exogenous and endogenous sources. Repair of AP lesions takes place predominantly by the base excision pathway (BER). However, among chemically heterogeneous AP lesions formed in DNA, some are resistant to the endonuclease APE1 and thus refractory to BER. Here, we employed two types of reporter constructs accommodating synthetic APE1-resistant AP lesions to investigate the auxiliary repair mechanisms in human cells. By combined analyses of recovery of the transcription rate and suppression of transcriptional mutagenesis at specifically positioned AP lesions, w…
DNA polymeraseθ up-regulation is associated with poor survival in breast cancer, perturbs DNA replication, and promotes genetic instability
2010
“Replicative stress” is one of the main factors underlying neoplasia from its early stages. Genes involved in DNA synthesis may therefore represent an underexplored source of potential prognostic markers for cancer. To this aim, we generated gene expression profiles from two independent cohorts (France,n= 206; United Kingdom,n= 117) of patients with previously untreated primary breast cancers. We report here that among the 13 human nuclear DNA polymerase genes, DNA Polymerase θ (POLQ) is the only one significantly up-regulated in breast cancer compared with normal breast tissues. Importantly,POLQup-regulation significantly correlates with poor clinical outcome (4.3-fold increased risk of de…
TWJ-Screen: an isothermal screening assay to assess ligand/DNA junction interactions in vitro
2017
International audience; The quest for chemicals able to operate at selected genomic loci in a spatiotemporally controlled manner is desirable to create manageable DNA damages. Mounting evidence now shows that alternative DNA structures, including G-quadruplexes and branched DNA (or DNA junctions), might hamper proper progression of replication fork, thus triggering DNA damages and genomic instability. Therefore, small molecules that stabilize these DNA structures are currently scrutinized as a promising way to create genomic defects that cannot be dealt with properly by cancer cells. While much emphasis has been recently given to G-quadruplexes and related ligands, we report herein on three…
Asynchronous replication dynamics of imprinted and non-imprinted chromosome regions in early mouse embryos.
2008
We have used interphase FISH to analyze the replication behavior of four imprinted chromosome regions (Snrpn, Zim1-Peg3, Dlk1-Gtl2, and Igf2r) and five non-imprinted regions in mouse one-cell to morula-stage embryos and embryonic fibroblasts. In general, imprinted chromosome regions showed the expected asynchronous pattern of replication throughout all analyzed stages of preimplantation development and in differentiated cells. The Dlk1-Gtl2 locus which is not expressed and Igf2r which is biallelically expressed in early embryos showed a relaxation of replication asynchrony at the morula stage. Asynchronous replication in zygotes and two-cell embryos was not specific to imprinted regions. Th…
Chromatin remodeling regulation by small molecules and metabolites.
2010
The eukaryotic genome is a highly organized nucleoprotein structure comprising of DNA, histones, non-histone proteins, and RNAs, referred to as chromatin. The chromatin exists as a dynamic entity, shuttling between the open and closed forms at specific nuclear regions and loci based on the requirement of the cell. This dynamicity is essential for the various DNA-templated phenomena like transcription, replication, and repair and is achieved through the activity of ATP-dependent chromatin remodeling complexes and covalent modifiers of chromatin. A growing body of data indicates that chromatin enzymatic activities are finely and specifically regulated by a variety of small molecules derived f…
Replication of the hepatitis C virus
2000
Infection with the hepatitis C virus (HCV) is a major cause of chronic liver disease. HCV is an enveloped plus-strand RNA virus closely related to flavi- and pestiviruses. The first cloning of the HCV genome, about 10 years ago, initiated research efforts leading to the elucidation of the genomic organization and the definition of the functions of most viral proteins. Despite this progress the lack of convenient animal models and appropriate in vitro propagation systems have hampered a full understanding of the way the virus multiplies. This review summarizes our current knowledge about HCV replication and describes attempts pursued in the last few years to establish efficient and reliable …
Improvement of baculovirus as protein expression vector and as biopesticide by CRISPR/Cas9 editing
2019
The clustered regularly interspaced short palindromic repeats (CRISPR) system?associated Cas9 endonuclease is a molecular tool that enables specific sequence editing with high efficiency. In this study, we have explored the use of CRISPR/Cas9 system for the engineering of baculovirus. We have shown that the delivering of Cas9-single guide RNA ribonucleoprotein (RNP) complex with or without DNA repair template into Sf21 insect cells through lipofection might be efficient to produce knockouts as well as knock-ins into the baculovirus. To evaluate potential application of our CRISPR/Cas9 method to improve baculovirus as protein expression vector and as biopesticide, we attempted to knockout se…
Complete Genome Sequence of “Candidatus Portiera aleyrodidarum” BT-QVLC, an Obligate Symbiont That Supplies Amino Acids and Carotenoids to Bemisia ta…
2012
ABSTRACT The genome of “ Candidatus Portiera aleyrodidarum,” the primary endosymbiont of the whitefly Bemisia tabaci (Mediterranean species), is reported. It presents a reduced genome (357 kb) encoding the capability to synthetize, or participate in the synthesis of, several amino acids and carotenoids, being the first insect endosymbiont capable of supplying carotenoids.
Comprehensive DNA methylation analysis of the Aedes aegypti genome
2016
AbstractAedes aegypti mosquitoes are important vectors of viral diseases. Mosquito host factors play key roles in virus control and it has been suggested that dengue virus replication is regulated by Dnmt2-mediated DNA methylation. However, recent studies have shown that Dnmt2 is a tRNA methyltransferase and that Dnmt2-dependent methylomes lack defined DNA methylation patterns, thus necessitating a systematic re-evaluation of the mosquito genome methylation status. We have now searched the Ae. aegypti genome for candidate DNA modification enzymes. This failed to reveal any known (cytosine-5) DNA methyltransferases, but identified homologues for the Dnmt2 tRNA methyltransferase, the Mettl4 (…