scholarly journals Transition Mutation

2020 ◽  
Author(s):  
Keyword(s):  
2019 ◽  
Vol 10 (3) ◽  
pp. 1640-1645
Author(s):  
Saleen Salam Abdulhadi ◽  
Abbas Abdullah Mohammed‎

In the present study, sequencing approach has been adopted for exploring the ‎genetic alteration of sequences for the ubiquitin gene (UBC) in patients of breast and ‎lung cancer and comparing the results with a normal sequence that obtained from NCBI. ‎The aim of this study was to detect for genetic alterations of UBC gene in the breast and ‎lung cancer patients then compare with healthy control subjects, to investigate the ‎association between the mutations at the intron region of the UBC gene and cancer disease, ‎‎40 blood samples were examined from patients with breast and lung cancer aged ranged from (17-65) years, were collected at Al-Amal Hospital of cancer in Baghdad ‎province/Iraq, the period of collecting samples were from October/2018 to January/2019. ‎While twenty-two blood samples from healthy control subjects were collected at ages ‎ranged from(19-59). After DNA extraction, the PCR primer was designed to amplify the ‎region in the UBC gene (part of exon 1 and the whole intron). Here we report the polymorphism of the intron sequence of the UBC gene in Iraqi population as the results of sequencing the PCR amplified products showed three different transition mutation G→A, ‎C→T, T→C in patients with breast cancer were also appeared in healthy control subjects. While nine transition mutations appeared in lung cancer patients, at different locations ‎of the sequence were detected by BLAST tool. ‎


1995 ◽  
Vol 15 (12) ◽  
pp. 6729-6735 ◽  
Author(s):  
J Liu ◽  
W Zhou ◽  
P W Doetsch

Dihydrouracil (DHU) is a major base damage product formed from cytosine following exposure of DNA to ionizing radiation under anoxic conditions. To gain insight into the DNA lesion structural requirements for RNA polymerase arrest or bypass at various DNA damages located on the transcribed strand during elongation, DHU was placed onto promoter-containing DNA templates 20 nucleotides downstream from the transcription start site. In vitro, single-round transcription experiments carried out with SP6 and T7 RNA polymerases revealed that following a brief pause at the DHU site, both enzymes efficiently bypass this lesion with subsequent rapid generation of full-length runoff transcripts. Direct sequence analysis of these transcripts indicated that both RNA polymerases insert primarily adenine opposite to the DHU site, resulting in a G-to-A transition mutation in the lesion bypass product. Such bypass and insertion events at DHU sites (or other types of DNA damages), if they occur in vivo, have a number of important implications for both the repair of such lesions and the DNA damage-induced production of mutant proteins at the level of transcription (transcriptional mutagenesis).


Author(s):  
Anna Backman Rogers

By way of conclusion and further development of the notion of a cinema of crisis, I will extend briefly this study’s theoretical framework to the work of Harmony Korine, Kelly Reichardt and the ‘Mumblecore’ movement – or, more specifically, the work of Lena Dunham. However, in order to outline these further facets of a cinema of crisis, it is necessary at this juncture to summarise what its salient features are. I argued at the beginning of this book that the dominant and established approach to American independent cinema in critical and scholarly studies is to categorise it in terms of economic, production and distribution strategies.1 While this is important and useful, this focus on the meaning and context of the very term ‘independent’ has resulted in a paucity of material on the aesthetics and poetics of this kind of cinema and its specific effect or affects. By focusing on the themes of crisis, liminality, transition, mutation and transformation, I have tried to emphasise the ways in which American independent cinema appropriates and transfigures the tropes of European ‘Art’ cinema (as set forth in Gilles Deleuze’s Cinema 2) for its own particular purposes in order to challenge entrenched modes of thought.


1998 ◽  
Vol 18 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Robert J. Duronio ◽  
Peter C. Bonnette ◽  
Patrick H. O’Farrell

ABSTRACT Activation of heterodimeric E2F-DP transcription factors can drive the G1-S transition. Mutation of the Drosophila melanogaster dE2F gene eliminates transcriptional activation of several replication factors at the G1-S transition and compromises DNA replication. Here we describe a mutation in theDrosophila dDP gene. As expected for a defect in the dE2F partner, this mutation blocks G1-S transcription ofDmRNR2 and cyclin E as previously described for mutations of dE2F. Mutation of dDP also causes an incomplete block of DNA replication. When S phase is compromised by reducing the activity of dE2F-dDP by either a dE2F ordDP mutation, the first phenotype detected is a reduction in the intensity of BrdU incorporation and a prolongation of the labeling. Notably, in many cells, there was no detected delay in entry into this compromised S phase. In contrast, when cyclin E function was reduced by a hypomorphic allele combination, BrdU incorporation was robust but the timing of S-phase entry was delayed. We suggest that dE2F-dDP contributes to the expression of two classes of gene products: replication factors, whose abundance has a graded effect on replication, and cyclin E, which triggers an all-or-nothing transition from G1 to S phase.


2017 ◽  
Author(s):  
Diego Borges-Rivera

Life continues to shock and amaze us, reminding us that truth is far stranger than fiction. http://Euplotid.io is a quantized, geometric model of the eukaryotic cell, an attempt at quantifying the incredible complexity that gives rise to a living cell by beginning from the smallest unit, a quanta. Starting from the very bottom we are able to build the pieces which when hierarchically and combinatorially combined produce the emergent complex behavior that even a single celled organism can show. Euplotid is composed of a set of quantized geometric 3D building blocks and constantly evolving dockerized bioinformatic pipelines enabling a user to build and interact with the local regulatory architecture of every gene starting from DNA-interactions, chromatin accessibility, and RNA-sequencing. Reads are quantified using the latest computational tools and the results are normalized, quality-checked, and stored. The local regulatory architecture of each gene is built using a Louvain based graph partitioning algorithm parameterized by the chromatin extrusion model and CTCF-CTCF interactions. Cis-Regulatory Elements are defined using chromatin accessibility peaks which are mapped to Transcriptional Start Sites based on inclusion within the same neighborhood. Deep Neural Networks are trained in order to provide a statistical model mimicking transcription factor binding, giving the ability to identify all Transcription Factors within a given chromatin accessibility peak. By in-silico mutating and re-applying the neural network we are able to gauge the impact of a transition mutation on the binding of any transcription factor. The annotated output can be visualized in a variety of 1D, 2D, 3D and 4D ways overlaid with existing bodies of knowledge such as GWAS results or PDB structures. Once a particular CRE of interest has been identified a Base Editor mediated transition mutation can then be performed in a relevant model for further study.


2010 ◽  
Vol 59 (8) ◽  
pp. 925-929 ◽  
Author(s):  
María A. Martínez ◽  
Mauricio Ruiz ◽  
Enna Zunino ◽  
Vivian Luchsinger ◽  
Raúl Aguirre ◽  
...  

This study was conducted to determine the types of M. pneumoniae prevalent in adults presenting with community-acquired pneumonia during an epidemic period, and to scrutinize a variable region of the RepMP4 element for the detection of P1 variants. All 23 clinical specimens PCR-positive for M. pneumoniae obtained in two hospitals in Santiago, Chile, from 2005 to 2006 were typed by a multiplex PCR directly and then the RepMP4 fragment of 18 specimens was sequenced. A predominance of M. pneumoniae type 2 was found, 18 (78.3 %) specimens being grouped as type 2 and 5 (21.7 %) as type 1. Co-infection of M. pneumoniae with other respiratory pathogens was found in 10/23 (43.4 %) patients, but their frequency was not related to the M. pneumoniae type. Sequence analysis revealed a single nucleotide polymorphism, a transition mutation, in 50 % of amplicons belonging to type 1 and in 71.4 % of amplicons of type 2. The nucleotide changes were synonymous in each P1 variant. In conclusion, during the 2005–2006 epidemic in Santiago, both types of M. pneumoniae circulated. Although the analysed area in the RepMP4 was small, we detected the existence of P1 variants in the two types of this organism.


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