Suchergebnisse

Changes on an organism by the exposure to environmental stressors may be characterized by hyperspectral images (HSI), which preserve the morphology of biological samples, and suitable chemometric tools. The approach proposed allows assessing and interpreting the effect of contaminant exposure on heterogeneous biological samples monitored by HSI at specific tissue levels. In this work, the model example used consists of the study of the effect of the exposure of chlorpyrifos-oxon on zebrafish tissues. To assess this effect, unmixing of the biological sample images followed by tissue-specific classification models based on the unmixed spectral signatures is proposed. Unmixing and classification are performed by multivariate curve resolution-alternating least squares (MCR-ALS) and partial least squares-discriminant analysis (PLS-DA), respectively. Crucial aspects of the approach are: (1) the simultaneous MCR-ALS analysis of all images from 1 population to take into account biological variability and provide reliable tissue spectral signatures, and (2) the use of resolved spectral signatures from control and exposed populations obtained from resampling of pixel subsets analyzed by MCR-ALS multiset analysis as information for the tissue-specific PLS-DA classification models. Classification results diagnose the presence of a significant effect and identify the spectral regions at a tissue level responsible for the biological change. ; The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. 32073 (CHEMAGEB project). The authors of this work belong to the network of recognized research groups by the Catalan government (2014 SGR 1106) and acknowledge the support of the Spanish government through project CTQ2015-66254-C2-2-P. ICFO would like to acknowledge financial support from Laserlab-Europe (EU-H2020 654148), the Spanish MINECO (Severo Ochoa grant SEV-2015-0522), Marató de TV3 (20142030), and the National Institute of Health (NIH, grant 5R21CA187890-02). The research conducted at ICFO's Super Resolution Light Microscopy and Nanoscopy Facility has been partially supported by Fundació Cellex Barcelona. ; Peer reviewed

Bacillus firmus I-1582 is approved in Europe for the management of Meloidogyne on vegetable crops. However, little information about its modes of action and temperature requirements is available, despite the effect of these parameters in its efficacy. The cardinal temperatures for bacterial growth and biofilm formation were determined. The bacteria was transformed with GFP to study its effect on nematode eggs and root colonization of tomato (Solanum lycopersicum) and cucumber (Cucumis sativus) by laser-scanning confocal microscopy. Induction of plant resistance was determined in split-root experiments and the dynamic regulation of genes related to jasmonic acid (JA) and salicylic acid (SA) by RT-qPCR at three different times after nematode inoculation. The bacteria was able to grow and form biofilms between 15 and 45°C; it degraded egg-shells and colonized eggs; it colonized tomato roots more extensively than cucumber roots; it induced systemic resistance in tomato, but not in cucumber; SA and JA related genes were primed at different times after nematode inoculation in tomato, but only the SA-related gene was up-regulated at 7 days after nematode inoculation in cucumber. In conclusion, B. firmus I-1582 is active at a wide range of temperatures; its optimal growth temperature is 35°C; it is able to degrade Meloidogyne eggs, and to colonize plant roots, inducing systemic resistance in a plant dependent species manner. ; Thanks are given to the Spanish Ministry of Economy and Competitiveness (MINECO) for funding the AGL2013-49040-C2-1-R project, to the Ministry of Science and Innovation from the Spanish Government for funding the AGL2017-89785-R, and to the European Regional Development Fund (FEDER). MC, JA, and PL-A acknowledges financial support from the Spanish Ministry of Economy and Competitiveness through the "Severo Ochoa" program for Centers of Excellence in R&D (SEV-2015-0522), from Fundació Privada Cellex, Fundación Mig-Puig and from Generalitat de Catalunya through the CERCA program and Laser lab Europe through the research and innovation programme under grant agreement No. 654148.

We present the implementation of a combined digital scanned light-sheet microscope (DSLM) able to work in the linear and nonlinear regimes under either Gaussian or Bessel beam excitation schemes. A complete characterization of the setup is performed and a comparison of the performance of each DSLM imaging modality is presented using in vivoCaenorhabditis elegans samples. We found that the use of Bessel beam nonlinear excitation results in better image contrast over a wider field of view. ; This work is supported by the Generalitat de Catalunya grant 2009-SGR-159, the Spanish government grants TEC2009-09698 and SAF2008-00211, the EU project STELUM (FP7-PEOPLE-2007-3-1-IAPP, 217997), the Swiss National Science Foundation (SNSF) Sinergia project grant CRSII3_125447, the FP7-NMP VIBRANT project grant CP-IP 228933-2, the NoE P4L and Laserlab optobio. Jacob Licea-Rodriguez acknowledges CONACYT Mexico for supporting his stay at ICFO through a mixed fellowship. This research has been partially supported by Fundació Cellex Barcelona and was mainly conducted at ICFO's "Super-Resolution Light Microscopy and Nanoscopy Facility"

The physical microenvironment regulates cell behavior during tissue development and homeostasis. How single cells decode information about their geometrical shape under mechanical stress and physical space constraints within tissues remains largely unknown. Here, using a zebrafish model, we show that the nucleus, the biggest cellular organelle, functions as an elastic deformation gauge that enables cells to measure cell shape deformations. Inner nuclear membrane unfolding upon nucleus stretching provides physical information on cellular shape changes and adaptively activates a calcium-dependent mechanotransduction pathway, controlling actomyosin contractility and migration plasticity. Our data support that the nucleus establishes a functional module for cellular proprioception that enables cells to sense shape variations for adapting cellular behavior to their microenvironment. ; Funding: V.V. acknowledges support from the ICFOstepstone PhD Programme funded by the European Union's Horizon 2020 research and innovation program under Marie Skłodowska-Curie grant agreement 665884. F.P. and Q.T.-R. acknowledge grants funded by Ministerio de Ciencia, Innovación y Universidades and Fondo Social Europeo (FSE) (BES2017-080523-SO, PRE2018-084393). M.A.V. acknowledges support from the Spanish Ministry of Science, Education and Universities through grant RTI2018-099718-B-100 and an institutional "Maria de Maeztu Programme" for Units of Excellence in R&D (CEX2018-000792-M) and FEDER funds.S.W. and M.K. acknowledge support from the Spanish Ministry of Economy and Competitiveness through the Severo Ochoa program for Centres of Excellence in R&D (CEX2019-000910-S), from Fundació Privada Cellex, Fundación Mig-Puig, and from Generalitat de Catalunya through the CERCA program and LaserLab (654148). M.K. acknowledges support through Spanish Ministry of Economy and Competitiveness (RYC-2015-17935, EQC2018-005048-P, AEI-010500-2018-228, and PGC2018-097882-A-I00),Generalitat de Catalunya (2017 SGR 1012), the ERC (715243), and the HFSPO (CDA00023/2018). S.W. acknowledges support through the Spanish Ministry of Economy and Competitiveness via MINECO's Plan Nacional (PGC2018-098532-A-I00). V.R. acknowledges support from the Spanish Ministry of Science and Innovation to the EMBL partnership, the Centro de Excelencia Severo Ochoa, the CERCA Programme/Generalitat de Catalunya, and the MINECO's Plan Nacional (BFU2017-86296-P)