Search results for " Regulation"
showing 10 items of 3187 documents
Cross-circulation and Cell Distribution Kinetics in Parabiotic Mice
2011
Blood-borne nucleated cells participate not only in inflammation, but in tissue repair and regeneration. Because progenitor and stem cell populations have a low concentration in the blood, the circulation kinetics and tissue distribution of these cells is largely unknown. An important approach to tracking cell lineage is the use of fluorescent tracers and parabiotic models of cross-circulation. Here, we investigated the cross-circulation and cell distribution kinetics of C57/B6 GFP(+)/wild-type parabionts. Flow cytometry analysis of the peripheral blood after parabiosis demonstrated no evidence for a "parabiotic barrier" based on cell size or surface characterstics; all peripheral blood cel…
High-throughput sequencing of RNA silencing-associated small RNAs in olive (Olea europaea L.).
2011
14 páginas, 5 figuras, 3 tablas, S4 figuras, S2 tablas
Nucleosome-specific, Time-dependent Changes in Histone Modifications during Activation of the Early Growth Response 1 (Egr1) Gene
2014
Histone post-translational modifications and nucleosome remodeling are coordinate events involved in eukaryotic transcriptional regulation. There are relatively few data on the time course with which these events occur in individual nucleosomes. As a contribution to fill this gap, we first describe the nature and time course of structural changes in the nucleosomes -2, -1, and +1 of the murine Egr1 gene upon induction. To initiate the transient activation of the gene, we used the stimulation of MLP29 cells with phorbol esters and the in vivo activation after partial hepatectomy. In both models, nucleosomes -1 and +1 are partially evicted, whereas nucleosomes +1 and -2 slide downstream durin…
Perturbation of spermine synthase Gene Expression and Transcript Profiling Provide New Insights on the Role of the Tetraamine Spermine in Arabidopsis…
2011
The role of the tetraamine spermine in plant defense against pathogens was investigated by using the Arabidopsis (Arabidopsis thaliana)-Pseudomonas viridiflava pathosystem. The effects of perturbations of plant spermine levels on susceptibility to bacterial infection were evaluated in transgenic plants (35S::spermine synthase [SPMS]) that overexpressed the SPMS gene and accumulated spermine, as well as in spms mutants with low spermine levels. The former exhibited higher resistance to P. viridiflava than wild-type plants, while the latter were more susceptible. Exogenous supply of spermine to wild-type plants also increased disease resistance. Increased resistance provided by spermine was p…
Coordinated Sumoylation and Ubiquitination Modulate EGF Induced EGR1 Expression and Stability
2011
Background Human early growth response-1 (EGR1) is a member of the zing-finger family of transcription factors induced by a range of molecular and environmental stimuli including epidermal growth factor (EGF). In a recently published paper we demonstrated that integrin/EGFR cross-talk was required for Egr1 expression through activation of the Erk1/2 and PI3K/Akt/Forkhead pathways. EGR1 activity and stability can be influenced by many different post-translational modifications such as acetylation, phosphorylation, ubiquitination and the recently discovered sumoylation. The aim of this work was to assess the influence of sumoylation on EGF induced Egr1 expression and/or stability. Methods We …
Comprehensive transcriptional analysis of the oxidative response in yeast
2008
The oxidative stress response in Saccharomyces cerevisiae has been analyzed by parallel determination of mRNA levels and transcription rates for the entire genome. A mathematical algorithm has been adapted for a dynamic situation such as the response to stress, to calculate theoretical mRNA decay rates from the experimental data. Yeast genes have been grouped into 25 clusters according to mRNA level and transcription rate kinetics, and average mRNA decay rates have been calculated for each cluster. In most of the genes, changes in one or both experimentally determined parameters occur during the stress response. 24% of the genes are transcriptionally induced without an increase inmRNAlevels…
Robust dynamical pattern formation from a multifunctional minimal genetic circuit.
2010
Abstract Background A practical problem during the analysis of natural networks is their complexity, thus the use of synthetic circuits would allow to unveil the natural mechanisms of operation. Autocatalytic gene regulatory networks play an important role in shaping the development of multicellular organisms, whereas oscillatory circuits are used to control gene expression under variable environments such as the light-dark cycle. Results We propose a new mechanism to generate developmental patterns and oscillations using a minimal number of genes. For this, we design a synthetic gene circuit with an antagonistic self-regulation to study the spatio-temporal control of protein expression. He…
Oxidative stress responses and lipid peroxidation damage are induced during dehydration in the production of dry active wine yeasts.
2009
The tolerance of the yeast Saccharomyces cerevisiae to desiccation is important for the use of this microorganism in the wine industry, since active dry wine yeast is routinely used as starter for must fermentations. Many studies have shown the complexity of the cellular effects caused by water loss, including oxidative injuries on macromolecular components. However the technological interest of yeast drying was not addressed in those studies, and the dehydration conditions were far from the industrial practice. In the present study a molecular approach was used to characterize the relevant injuring conditions during pilot plant dehydrations under two different drying temperatures (i.e., 35…
Analysing the Spanish smoke-free legislation of 2006: a new method to quantify its impact using a dynamic model.
2011
Background: There are many models that study aspects of smoking habits: the influence of price, tax, relapse time, and the effects of prohibition. There are also studies examining the effects of the Spanish smoke-free law. We wanted to build a model able to separate the effect of the law from the pre-law evolution of smoking habits. Methods: Using data from the Spanish Ministry of Health and Social Policy, we developed a dynamic model of tobacco use. The model projects the evolution over time of the number of non-smokers, smokers and ex-smokers before 2006. Then, we compared the predictions of the model with data for the years after the law came into force, 2006 and 2009. Results: We show t…
D2R striatopallidal neurons inhibit both locomotor and drug reward processes.
2009
The specific functions of dopamine D(2) receptor-positive (D(2)R) striatopallidal neurons remain poorly understood. Using a genetic mouse model, we found that ablation of D(2)R neurons in the entire striatum induced hyperlocomotion, whereas ablation in the ventral striatum increased amphetamine conditioned place preference. Thus D(2)R striatopallidal neurons limit both locomotion and, unexpectedly, drug reinforcement.