Search results for " Genes"
showing 10 items of 322 documents
Solving Rate of Change Tasks with a Graphing Calculator: a Case Study on Instrumental Genesis
2016
In an increasing number of mathematics classes throughout the world, technology is being used for the teaching and learning of mathematics. But knowledge is limited about the long-term development of students’ mathematical thinking when learning mathematics with the use of technology. This article reports on the development of a student and the role of the graphing calculator (GC) in his learning about derivatives and instantaneous rate of change. This case is compelling, because the student is an intensive user of the GC and develops flexible problem-solving techniques – techniques which differ from those of his peers and from what he was taught in mathematics class. We used the framework …
Assessing the impact of copy number variants on miRNA genes in autism by Monte Carlo simulation.
2014
Autism Spectrum Disorders (ASDs) are childhood neurodevelopmental disorders with complex genetic origins. Previous studies have investigated the role of de novo Copy Number Variants (CNVs) and microRNAs as important but distinct etiological factors in ASD. We developed a novel computational procedure to assess the potential pathogenic role of microRNA genes overlapping de novo CNVs in ASD patients. Here we show that for chromosomes # 1, 2 and 22 the actual number of miRNA loci affected by de novo CNVs in patients was found significantly higher than that estimated by Monte Carlo simulation of random CNV events. Out of 24 miRNA genes over-represented in CNVs from these three chromosomes only …
Phenotypic and genotypic evaluation of slime production by conventional and molecular microbiological techniques.
2009
Twenty-nine staphylococcal isolates from different clinical samples were tested for slime production: phenotypic characterization was carried out using Christensen test (tube test) and Congo red agar plate test (CRA plate test), while the presence and expression of icaA and icaD genes were evaluated by real-time PCR. In 79.3% of studied strains there was a concordance between slime production and presence of icaA and icaD genes, and between lack of slime production and absence of both or only one of the tested genes. In four of five strains where positive phenotype was not associated with the presence of ica genes, gene co-expression (evaluated by mRNA determination) was lacking, while in o…
Genome-wide detection of signatures of selection in three Valdostana cattle populations
2020
International audience; The Valdostana is a local dual purpose cattle breed developed in Italy. Three populations are recognized within this breed, based on coat colour, production level, morphology and temperament: Valdostana Red Pied (VPR), Valdostana Black Pied (VPN) and Valdostana Chestnut (VCA). Here, we investigated putative genomic regions under selection among these three populations using the Bovine 50K SNP array by combining three different statistical methods based either on allele frequencies (F-ST) or extended haplotype homozygosity (iHS and Rsb). In total, 8, 5 and 8 chromosomes harbouring 13, 13 and 16 genomic regions potentially under selection were identified by at least tw…
A Mutually Stimulating Loop Involving Emx2 and Canonical Wnt Signalling Specifically Promotes Expansion of Occipital Cortex and Hippocampus
2005
The correct size of the different areas composing the mature cerebral cortex depends on the proper early allocation of cortical progenitors to their distinctive areal fates, as well as on appropriate subsequent tuning of their area-specific proliferation--differentiation profiles. Whereas much is known about the genetics of the former process, the molecular mechanisms regulating proliferation and differentiation rates within distinctive cortical proto-areas are still largely obscure. Here we show that a mutual stimulating loop, involving Emx2 and canonical Wnt signalling, specifically promotes expansion of the occipito-hippocampal anlage. Collapse of this loop occurring in Emx2 2/2 mutants …
Polymorphism of cytochrome P450 (CYP) genes and response to chemiotherapy in patients with colorectal cancer (CRC)
2014
Background: Genes coding for the cytochrome P450 (CYP) enzyme system implied in antineoplastic drug metabolism pathways are highly polymorphic. This may influence both carcinogen metabolism and drug pharmacodynamics modifying their therapeutic efficacy and side effects. Methods: We investigated the influence of genetic polymorphisms of CYP enzymes: rs1799853 (CYP2C9), rs35742686 (CYP2D), rs5030655 (CYP2D6/3), rs2740574 (CYP3A4/1) rs776746 (CYP3A5) on the response of chemotherapy and clinical outcomes, in a group of 56 patients affected by sporadic CRC, treated with the standard protocols. A total of 44 patients were in complete remission after treatment, 12 had persistence of the disease. P…
Dynamic regulation of the cancer stem cell compartment by Cripto-1 in colorectal cancer.
2015
Stemness was recently depicted as a dynamic condition in normal and tumor cells. We found that the embryonic protein Cripto-1 (CR1) was expressed by normal stem cells at the bottom of colonic crypts and by cancer stem cells (CSCs) in colorectal tumor tissues. CR1-positive populations isolated from patient-derived tumor spheroids exhibited increased clonogenic capacity and expression of stem-cell-related genes. CR1 expression in tumor spheroids was variable over time, being subject to a complex regulation of the intracellular, surface and secreted protein, which was related to changes of the clonogenic capacity at the population level. CR1 silencing induced CSC growth arrest in vitro with a …
A loop involving NRF2, miR‐29b‐1‐5p and AKT, regulates cell fate of MDA‐MB‐231 triple‐negative breast cancer cells
2019
The present study shows that nuclear factor erythroid 2-related factor 2 (NRF2) and miR-29b-1-5p are two opposite forces which could regulate the fate of MDA-MB-231 cells, the most studied triple-negative breast cancer (TNBC) cell line. We show that NRF2 activation stimulates cell growth and markedly reduces reactive oxygen species (ROS) generation, whereas miR-29b-1-5p overexpression increases ROS generation and reduces cell proliferation. Moreover, NRF2 downregulates miR-29b-1-5p expression, whereas miR-29b-1-5p overexpression decreases p-AKT and p-NRF2. Furthermore, miR-29b-1-5p overexpression induces both inhibition of DNA N-methyltransferases (DNMT1, DNMT3A, and DNMT3B) expression and …
Taxonomic and functional diversity of atrazine‐degrading bacterial communities enriched from agrochemical factory soil
2010
Aims: To characterize atrazine-degrading potential of bacterial communities enriched from agrochemical factory soil by analysing diversity and organization of catabolic genes. Methods and Results: The bacterial communities enriched from three different sites of varying atrazine contamination mineralized 65–80% of 14C ring-labelled atrazine. The presence of trzN-atzBC-trzD, trzN-atzABC-trzD and trzN-atzABCDEF-trzD gene combinations was determined by PCR. In all enriched communities, trzN-atzBC genes were located on a 165-kb plasmid, while atzBC or atzC genes were located on separated plasmids. Quantitative PCR revealed that catabolic genes were present in up to 4% of the community. Restricti…
Vip3C, a novel class of vegetative insectidal proteins from Bacillus thuringiensis
2012
Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 οg/cm 2. © 2012, American Society for Microbiology.