Publications

by Keyword: Zebrafish


By year:[ 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 ]

Hernández-Vega, Amayra, Marsal, María, Pouille, Philippe-Alexandre, Tosi, Sébastien, Colombelli, Julien, Luque, Tomás, Navajas, Daniel, Pagonabarraga, Ignacio, Martín-Blanco, Enrique, (2017). Polarized cortical tension drives zebrafish epiboly movements EMBO Journal 36, (1), 25-41

The principles underlying the biomechanics of morphogenesis are largely unknown. Epiboly is an essential embryonic event in which three tissues coordinate to direct the expansion of the blastoderm. How and where forces are generated during epiboly, and how these are globally coupled remains elusive. Here we developed a method, hydrodynamic regression (HR), to infer 3D pressure fields, mechanical power, and cortical surface tension profiles. HR is based on velocity measurements retrieved from 2D+T microscopy and their hydrodynamic modeling. We applied HR to identify biomechanically active structures and changes in cortex local tension during epiboly in zebrafish. Based on our results, we propose a novel physical description for epiboly, where tissue movements are directed by a polarized gradient of cortical tension. We found that this gradient relies on local contractile forces at the cortex, differences in elastic properties between cortex components and the passive transmission of forces within the yolk cell. All in all, our work identifies a novel way to physically regulate concerted cellular movements that might be instrumental for the mechanical control of many morphogenetic processes.

Keywords: Epiboly, Hydrodynamics, Mechanics, Morphogenesis, Zebrafish


Marsal, Maria, Jorba, Ignasi, Rebollo, Elena, Luque, Tomas, Navajas, Daniel, Martín-Blanco, Enrique, (2017). AFM and microrheology in the zebrafish embryo yolk cell Journal of Visualized Experiments Developmental Biology, (129), e56224

Elucidating the factors that direct the spatio-temporal organization of evolving tissues is one of the primary purposes in the study of development. Various propositions claim to have been important contributions to the understanding of the mechanical properties of cells and tissues in their spatiotemporal organization in different developmental and morphogenetic processes. However, due to the lack of reliable and accessible tools to measure material properties and tensional parameters in vivo, validating these hypotheses has been difficult. Here we present methods employing atomic force microscopy (AFM) and particle tracking with the aim of quantifying the mechanical properties of the intact zebrafish embryo yolk cell during epiboly. Epiboly is an early conserved developmental process whose study is facilitated by the transparency of the embryo. These methods are simple to implement, reliable, and widely applicable since they overcome intrusive interventions that could affect tissue mechanics. A simple strategy was applied for the mounting of specimens, AFM recording, and nanoparticle injections and tracking. This approach makes these methods easily adaptable to other developmental times or organisms.

Keywords: Developmental Biology, Zebrafish, Yolk, Atomic Force Microscopy, Cortical Tension, Microrheology, Nanoparticle tracking


Tekeli, I., Aujard, I., Trepat, X., Jullien, L., Raya, A., Zalvidea, D., (2016). Long-term in vivo single-cell lineage tracing of deep structures using three-photon activation Light: Science and Applications 5, (6), e16084

Genetic labeling techniques allow for noninvasive lineage tracing of cells in vivo. Two-photon inducible activators provide spatial resolution for superficial cells, but labeling cells located deep within tissues is precluded by scattering of the far-red illumination required for two-photon photolysis. Three-photon illumination has been shown to overcome the limitations of two-photon microscopy for in vivo imaging of deep structures, but whether it can be used for photoactivation remains to be tested. Here we show, both theoretically and experimentally, that three-photon illumination overcomes scattering problems by combining longer wavelength excitation with high uncaging three-photon cross-section molecules. We prospectively labeled heart muscle cells in zebrafish embryos and found permanent labeling in their progeny in adult animals with negligible tissue damage. This technique allows for a noninvasive genetic manipulation in vivo with spatial, temporal and cell-type specificity, and may have wide applicability in experimental biology.

Keywords: Multi-photon microscopy, Photoactivation, Three-photon microscopy, Zebrafish