Search results for "COD"
showing 10 items of 2985 documents
IAP et Rho : enfin connectées
2014
231 m/s n° 3, vol. 30, mars 2014 DOI : 10.1051/medsci/20143003003 5. Apcher S, Millot G, Daskalogianni C, et al. Translation of pre-spliced RNAs in the nuclear compartment generates peptides for the MHC class I pathway. Proc Natl Acad Sci USA 2013 ; 110 : 17951-6. 6. de Turris V, Nicholson P, Orozco RZ, et al. Cotranscriptional effect of a premature termination codon revealed by live-cell imaging. RNA 2011 ; 17 : 2094-107. 7. Iborra FJ, Jackson DA, Cook PR. Coupled transcription and translation within nuclei of mammalian cells. Science 2001 ; 293 : 1139-42. 8. David A, Dolan BP, Hickman HD, et al. Nuclear translation visualized by ribosome-bound nascent chain puromycylation. J Cell Biol 201…
Chromatin structure of the yeast FBP1 gene: transcription-dependent changes in the regulatory and coding regions.
1993
We have studied the chromatin structure of the Saccharomyces cerevisiae FBP1 gene, which codes for fructose-1,6-bisphosphatase. A strong, constitutive, DNase I, micrococcal nuclease and S1 nuclease hypersensitive site is present close to the 3′ end of the coding region. In the repressed state, positioned nucleosomes exist around this site, and subtle changes occur in this nucleosomal organization upon derepression. A DNase I hypersensitive region is located within the promoter between positions −540 and −400 and it extends towards the gene in the derepressed state, leading to an alteration of nucleosomal positioning. Psoralen crosslinking of chromatin, which is used for the first time to st…
RNA memory model: a RNA-mediated transcriptional activation mechanism involved in cell identity.
2010
Position-effect variegation (PEV) was discovered in Drosophila melanogaster in 1930 in a study of X-ray-induced chromosomal rearrangements. If a rearrangement places euchromatic genes adjacent to a region of centromeric heterochromatin, it gives a variegated phenotype that results from the random inactivation of genes by heterochromatin spreading from the breakpoint. After the establishment, the inactivation is henceforth clonally inherited. The vast majority of these modifiers were originally isolated in Drosophila as dominant mutations that suppressed or enhanced the variegation caused by a variegating white allele called white-mottled 4 (wm4). A large number of modifier genes alter PEV p…
Dynamic remodeling of histone modifications in response to osmotic stress in Saccharomyces cerevisiae.
2014
Abstract Background Specific histone modifications play important roles in chromatin functions; i.e., activation or repression of gene transcription. This participation must occur as a dynamic process. Nevertheless, most of the histone modification maps reported to date provide only static pictures that link certain modifications with active or silenced states. This study, however, focuses on the global histone modification variation that occurs in response to the transcriptional reprogramming produced by a physiological perturbation in yeast. Results We did a genome-wide chromatin immunoprecipitation analysis for eight specific histone modifications before and after saline stress. The most…
UAV-Aided Multi-Antenna Covert Communication Against Multiple Wardens
2021
In this paper, we propose a UAV-aided covert communication scheme assisted by a multi-antenna jammer to maximize the transmission rate between a ground transmitter and a UAV receiver against several randomly distributed wardens. The transmitter adopts the maximum ratio transmission, while the jammer zero-forces its transmitted signal at the UAV to disturb the monitoring at wardens without interfering the legitimate transmission. First, we analyze the detection performance and derive the optimal threshold for each warden to minimize its detection outage probability (DOP). Then, with the worst situation in which all wardens set their respective optimal thresholds to achieve the minimum global…
Performance evaluation of the MPE-iFEC Sliding RS Encoding for DVB-H streaming services
2008
This article studies the performance of the Sliding RS Encoding (SRSE) in the transmission of streaming services in DVB-H (Digital Video Broadcasting - Transmission System for Handheld Terminals) networks. The SRSE forms part of a set of specifications called MPE-iFEC which has been recently defined in the DVB-SH (Digital Video Broadcasting - Satellite Services to Handheld Devices) standard and is fully compatible with the link layer of DVB-H. MPE-iFEC is capable of encoding information related to different datagram bursts in a jointly manner in order to counteract the long signal blockages expected in satellite reception. This is what is usually referred to as Multi-Burst Encoding (MBE) an…
Multi-resolution quality-based video coding system for DASH scenarios
2021
Today, more than 85% of Internet traffic has a multimedia component. Video streaming occupies a large part of this percentage mainly because this type of content is provided by the most used applications on the Internet (e.g. Twitch, TikTok, Disney+, YouTube, Netflix, etc.). Most of these platforms use HTTP Adaptive Streaming (HAS) to send this media content to end users in order to ensure a good quality of experience (QoE). But, this QoE should be guaranteed from the video to be transmitted, i.e., the video should have an adequate quality by minimizing the bitrate before transmission. In order to solve this issue, we present a system capable of encoding a video in several resolutions given…
TAF-ChIP: An ultra-low input approach for genome wide chromatin immunoprecipitation assay
2018
Chromatin immunoprecipitation (ChIP) followed by next generation sequencing is an invaluable and powerful technique to understand transcriptional regulation. However, ChIP is currently limited by the requirement of large amount of starting material. This renders studying rare cell populations very challenging, or even impossible. Here, we present a tagmentation-assisted fragmentation ChIP (TAF-ChIP) and sequencing method to generate high-quality datasets from low cell numbers. The method relies on Tn5 transposon activity to fragment the chromatin that is immunoprecipitated, thus circumventing the need for sonication or MNAse digestion to fragment. Furthermore, Tn5 adds the sequencing adapto…
Aberrant splicing of the Drosophila melanogaster phenylalanine hydroxylase pre-mRNA caused by the insertion of a B104/roo transposable element in the…
1999
Abstract We report the insertion of the transposable element B104 in the Phenylalanine hydroxylase gene of the Drosophila mutant Henna-recessive 3 . Its presence alters the Phenylalanine hydroxylase splicing pattern, producing at least two aberrant mRNAs which contain part of the B104 sequence interrupting the coding region. This aberrant splicing is provoked by the use of a cryptic donor site encoded by the B104 3′ long terminal repeat in combination with either the gene intron 3 acceptor site or a novel acceptor site generated by the target duplication caused by transposition. One of them, referred as mRNA type 1, encodes a truncated protein that could be predictably non-functional. In mR…
Structural and evolutionary analysis of the copia-like elements in the Arabidopsis thaliana genome.
2001
The analysis of 460 kb of genomic sequence of Arabidopsis thaliana chromosome III allowed us to identify two new transposable elements named AtC1 and AtC2. AtC1 shows identical long terminal repeats (LTRs) and all the structural features characteristic of the copia-like active elements. AtC2 is also a full copia-like element, but a putative stop codon in the open reading frame (ORF) would produce a truncated protein. In order to identify the copia-like fraction of the A. thaliana genome, a careful computer-based analysis of the available sequences (which correspond to 92% of the genome) was performed. Approximately 300 nonredundant copia-like sequences homologous to AtC1 and AtC2 were detec…