Genomic architecture, gene regulation and human diseases

Resumen del trabajo presentado al IX Meeting of the Spanish Society for Developmental Biology celebrado en Granada del 12 al 14 de noviembre de 2012.Peer Reviewe

Sox21a is requiered for posterior lateral line patterning by regulating Fgf signalling

Resumen del póster presentado al IX Meeting of the Spanish Society for Developmental Biology celebrado en Granada del 12 al 14 de noviembre de 2012.Peer Reviewe

Engineered Salmonella allows real-time heterologous gene expression monitoring within infected zebrafish embryos

Short communication.Microbial host–pathogen interactions have been traditionally well studied at genetic and physiological levels, but cell-resolution analyses have been particularly scarce. This has been especially remarkable for intracellular parasites for two major reasons: first, the inherent loss of bacteria traceability once infects its hosts; second and more important, the limited availability of genetic tools that allow a tight regulated expression of bacterial virulence genes once inside the host tissues. Here we present novel data supporting the use of zebrafish embryos to monitor Salmonella enterica serovar Thyphimurium infection. Intravenous infection of Salmonella can be easily monitored using in vivo fluorescence that allows the visualization of free-swimming bacteria through the circulatory system. Moreover, we have engineered Salmonella to voluntarily activate heterologous gene expression at any point during infection once inside the zebrafish macrophages using a salicylate-based expression system. This approach allows real-time cell-resolution in vivo monitoring of the infection. All together, this approach paves the road to cell-based resolution experiments that would be harder to mimic in other vertebrate infection models.his work was funded by grants BFU2010-14839, CSD2007-00008, CSD2007-00005 and Proyectos de Excelencia CVI-3488 and P07-CVI-02518 from the Spanish and Andalusian Governments, respectively. Jose Luis Royo holds a JAE DOC contract from the Spanish National Research Council (CSIC).Peer reviewe

Silencing of Smed-βcatenin1 generates radial-like hypercephalized planarians

7 páginas, 4 figuras. Supplementary material for this article is available at http://dev.biologists.org/cgi/content/full/135/7/1215/DC1Little is known about the molecular mechanisms responsible for axis establishment during non-embryonic processes such as regeneration and homeostasis. To address this issue, we set out to analyze the role of the canonical Wnt pathway in planarians, flatworms renowned for their extraordinary morphological plasticity. Canonical Wnt signalling is an evolutionarily conserved mechanism to confer polarity during embryonic development, specifying the anteroposterior (AP) axis in most bilaterians and the dorsoventral (DV) axis in early vertebrate embryos. β-Catenin is a key element in this pathway, although it is a bifunctional protein that is also involved in cell-cell adhesion. Here, we report the characterization of two β-catenin homologs from Schmidtea mediterranea (Smed-βcatenin1/2). Loss of function of Smed-βcatenin1, but not Smed-βcatenin2, in both regenerating and intact planarians, generates radial-like hypercephalized planarians in which the AP axis disappears but the DV axis remains unaffected, representing a unique example of a striking body symmetry transformation. The radial-like hypercephalized phenotype demonstrates the requirement for Smed-βcatenin1 in AP axis re-establishment and maintenance, and supports a conserved role for canonical Wnt signalling in AP axis specification, whereas the role of β-catenin in DV axis establishment would be a vertebrate innovation. When considered alongside the protein domains present in each S. mediterranea β-catenin and the results of functional assays in Xenopus embryos demonstrating nuclear accumulation and axis induction with Smed-βcatenin1, but not Smed-βcatenin2, these data suggest that S. mediterraneaβ -catenins could be functionally specialized and that only Smed-βcatenin1 is involved in Wnt signalling.This work was supported by grants from the Ministerio de Educación y Ciencia, Spain, from AGAUR (Generalitat de Catalunya, Spain), and from La Junta de Andalucía, Spain.Peer reviewe

Regulatory landscape of the vertebrate six2/six3 locus

Resumen del póster presentado al IX Meeting of the Spanish Society for Developmental Biology celebrado en Granada del 12 al 14 de noviembre de 2012.Peer Reviewe

Architecture and evaluation of a unified V2V and V2I communication system based on cellular networks

Vehicle communications are becoming the cornerstone in the future vehicle equipment. More specifically, vehicle to vehicle communications (V2V) are the main object of researching nowadays, because vehicle to infrastructure (V2I) approximations are already being developed as commercial solutions. Cellular networks (CN) are usually applied in V2I solutions, whereas ad hoc networks are practically the only technology considered in V2V communications. Due to fact that CN are currently a reality and the operators are continuously improving the network, this communication technology could be considered as a candidate to deal with V2V necessities as well. The present paper defends the applicability of CN in the V2V field, and presents a novel communication paradigm for vehicles which unifies both V2V and V2I paradigms into one system. A peer to peer network technology has been used over the CN basis to create a group-based communication infrastructure which enables the message propagation among vehicles and between the car and the road side infrastructure. The architecture has been implemented in both hardware and software terms, and multitude of field tests have been carried out, whose main performance results are shown in the paper.The authors would like to thank the Spanish Ministerio the Educacion y Ciencia for sponsoring the research activities under the grant AP2005-1437, in frames of the FPU program, and to the financial support given by the European Spatial Agency (ESA) under the GIROADS 332599 project. Special thanks as well to the Spanish Ministerio the Fomento for its continuous support in vehicular researching

Temporal lack of DNA methylation-mediated repression is a universal feature of vertebrate development

Resumen del póster presentado al IX Meeting of the Spanish Society for Developmental Biology celebrado en Granada del 12 al 14 de noviembre de 2012.-- et al.Peer Reviewe

Long-range regulatory interactions at the 4q25 atrial fibrillation risk locus involve PITX2c and ENPEP

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Recent genome-wide association studies have uncovered genomic loci that underlie an increased risk for atrial fibrillation, the major cardiac arrhythmia in humans. The most significant locus is located in a gene desert at 4q25, approximately 170 kilobases upstream of PITX2, which codes for a transcription factor involved in embryonic left-right asymmetry and cardiac development. However, how this genomic region functionally and structurally relates to PITX2 and atrial fibrillation is unknown. [Results]: To characterise its function, we tested genomic fragments from 4q25 for transcriptional activity in a mouse atrial cardiomyocyte cell line and in transgenic mouse embryos, identifying a non-tissue-specific potentiator regulatory element. Chromosome conformation capture revealed that this region physically interacts with the promoter of the cardiac specific isoform of Pitx2. Surprisingly, this regulatory region also interacts with the promoter of the next neighbouring gene, Enpep, which we show to be expressed in regions of the developing mouse heart essential for cardiac electrical activity. [Conclusions]: Our data suggest that de-regulation of both PITX2 and ENPEP could contribute to an increased risk of atrial fibrillation in carriers of disease-associated variants, and show the challenges that we face in the functional analysis of genome-wide disease associations.This study was funded by the CNIC Translational Grant Programme (CNIC-08-2009 to MM and DF), the Spanish Ministerio de Economia y Competitividad (grants BFU2011-23083 to MM, BFU2013-41322-P to JLGS, BFU2012-38111 to AA, and CSD2007-00008 to JLGS and MM), the Comunidad Autónoma de Madrid (grant CELLDD-CM to MM), and the Andalusian Government (grant BIO-396 to JLGS). The CNIC is supported by the Spanish Ministerio de Economia y Competitividad and the Pro-CNIC Foundation.Peer Reviewe

Identification and Analysis of Conserved cis-Regulatory Regions of the MEIS1 Gene

Meis1, a conserved transcription factor of the TALE-homeodomain class, is expressed in a wide variety of tissues during development. Its complex expression pattern is likely to be controlled by an equally complex regulatory landscape. Here we have scanned the Meis1 locus for regulatory elements and found 13 non-coding regions, highly conserved between humans and teleost fishes, that have enhancer activity in stable transgenic zebrafish lines. All these regions are syntenic in most vertebrates. The composite expression of all these enhancer elements recapitulate most of Meis1 expression during early embryogenesis, indicating they comprise a basic set of regulatory elements of the Meis1 gene. Using bioinformatic tools, we identify a number of potential binding sites for transcription factors that are compatible with the regulation of these enhancers. Specifically, HHc2:066650, which is expressed in the developing retina and optic tectum, harbors several predicted Pax6 sites. Biochemical, functional and transgenic assays indicate that pax6 genes directly regulate HHc2:066650 activity.This work was funded through grants BFU2009-07044 (MICINN) and Proyecto de Excelencia CVI 2658 (Junta de Andalucía) to FC and BFU2010-14839 (MICINN), CSD2007-00008 and Proyecto de Excelencia CVI-3488 to JLGS. JLR is a recipient of a JAE-DOC contract from the Spanish National Research Council (CSIC)

Assessment of VANET multi-hop routing over an experimental platform

International audienceEvaluation of vehicular ad-hoc networks (VANETs) over real environments is still a remaining issue for most researchers. There are some works which carry out performance tests to evaluate the communication channel according to physical and MAC conditions. Only a few works deal with multi-hop experimentation in this field, and practically none tests multi- hop protocols. In this paper an integral VANET testbed is evaluated, using 802.11b and a multi-hop network managed by the Optimized Link State Routing protocol (OLSR). Up to four vehicles are used to study the VANET performance over different traffic environments and different metrics are considered to analyse the results in terms of delay, bandwidth, packet loss and distance between nodes. Furthermore, a deeper analysis is carried out to track the routes followed by packets end to end. Since a routing protocol is used, results differ from traditional one-hop and static-route tests, presenting a more realistic study