Search results for "Regulatory network"
showing 10 items of 130 documents
Inducible and reversible inhibition of miRNA-mediated gene repression in vivo
2021
Although virtually all gene networks are predicted to be controlled by miRNAs, the contribution of this important layer of gene regulation to tissue homeostasis in adult animals remains unclear. Gain and loss of function experiments have provided key insights into the specific function of individual miRNAs, but effective genetic tools to study the functional consequences of global inhibition of miRNA activity in vivo are lacking. Here we report the generation and characterization of a genetically engineered mouse strain in which miRNA-mediated gene repression can be reversibly inhibited without affecting miRNA biogenesis or abundance. We demonstrate the usefulness of this strategy by invest…
GAM/ZFp/ZNF512B is central to a gene sensor circuitry involving cell-cycle regulators, TGF beta effectors, Drosha and microRNAs with opposite oncogen…
2010
MicroRNAs (miRNAs) are small regulatory RNAs targeting multiple effectors of cell homeostasis and development, whose malfunctions are associated with major pathologies such as cancer. Herein we show that GAM/ZFp/ZNF512B works within an intricate gene regulatory network involving cell-cycle regulators, TGFβ effectors and oncogenic miRNAs of the miR-17-92 cluster. Thus, GAM impairs the transcriptional activation of the miR-17-92 promoter by c-Myc, downregulates miR-17-92 miRNAs differentially, and limits the activation of genes responsive to TGFβ canonical pathway. In contrast, TGFβ decreases GAM transcripts levels while differentially upregulating miR-17-92 miRNAs. In turn, miR-17, miR-20a a…
Status and prospects of systems biology in grapevine research
2019
The cultivated grapevine, Vitis vinifera L., has gathered a vast amount of omics data throughout the last two decades, driving the imperative use of computational resources for its analysis and integration. Molecular systems biology arises from this need allowing to model and predict the emergence of phenotypes or responses in biological systems. Beyond single omics networks, integrative approaches associate the molecular components of an organism and combine them into higher order networks to model dynamic behaviors. Application of network-based methods in multi-omics data is providing additional resources to address important questions regarding grapevine fruit quality and composition. He…
Dorsal/Ventral asymmetric expression of nodal in the early sea urchin embryo relies on specific suppression in dorsal cells by the Hbox12 homeodomain…
2014
Dorsal/Ventral (DV) polarization of the sea urchin embryo is directed by a Nodal-expressing signaling centre located on the ventral side. The initial breaking of the symmetry and positioning of the organizer are unclear. We show that, in Paracentrotus lividus embryos, the Hbox12 homeodomaincontaining repressor is expressed on the opposite side and precedes the onset of nodal transcription. Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent gene transcription. Reciprocally, clonal hbox12 loss-of-function imposed by blastomere transplantation or gene transfer assays disrupts DV polarization and allows ectopic expression of nodal. Remarkably, the localized kn…
"A KNOWLEDGE-BASED EXPERT SYSTEM IN BIOINFORMATICS: AN APPLICATION TO REVERSE ENGINEERING GENE REGULATORY NETWORK"
2011
The huge amount of biological data has spread the development of plenty of bionformatics tools, databases and web services. In order to face a computational biology problem, there not exist only a way, but different methodologies and strategies, with their own pros and cons, can be applied. In this PhD thesis I present a knowledge-based expert system that aims at helping a bionformatics researcher in the choice of the proper strategy and heuristic in order to resolve a bioinformatics issue. The Knowledge Base of the system is structured by means of an ontology and codes the expertise about the application domain. KB is organized into decision-making modules that introduce a set of metareaso…
MicroRNAs in Colorectal Cancer Drug Resistance: Shooters become Targets
2013
Copyright: © 2013 Fanale D, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. MicroRNAs (MiRNAs) are involved in the regulation of several biological processes such as development, differentiation, metabolism, apoptosis and proliferation. Recently, it has been shown that deregulated expression of miRNAs are present in different human cancers, suggesting a potential role in carcinogenesis [1,2]. Recent evidence suggests that miRNAs may represent potential new therapeutic approaches in patients with dru…
Robustness of dynamic gene regulatory networks in Neisseria
2014
Gene regulatory networks are made of highly tuned, sparse and dynamical operations. We consider the case of the Neisseria meningitidis bacterium, a causative agent of life-threatening infections such as meningitis, and aim to infer a robust net- work of interactions across sixty proteins based on a detailed time course gene expres- sion study. We consider the problem of estimating a sparse dynamic Gaussian graphical model with L1 penalized maximum likelihood under a structured precision matrix. The structure can consist of specific time dynamics, known presence or absence of links in the graphical model or equality constraints on the parameters. The authors developed a new optimization algo…
Pathway analysis of high-throughput biological data within a Bayesian network framework
2011
Abstract Motivation: Most current approaches to high-throughput biological data (HTBD) analysis either perform individual gene/protein analysis or, gene/protein set enrichment analysis for a list of biologically relevant molecules. Bayesian Networks (BNs) capture linear and non-linear interactions, handle stochastic events accounting for noise, and focus on local interactions, which can be related to causal inference. Here, we describe for the first time an algorithm that models biological pathways as BNs and identifies pathways that best explain given HTBD by scoring fitness of each network. Results: Proposed method takes into account the connectivity and relatedness between nodes of the p…
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
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…