Quantitative Morphogenesis Laboratory

University of Toronto

Mesectoderm cell division and ME boundary formation in an embryo expressing Gap43:mCherry (left, magenta; centre) and Myosin:GFP (left, green; right). A stack was acquired every 2 min. Time is with respect to the onset of mesectoderm cell division. Anterior, left.

Source: Yu JC*, Balaghi N*, Erdemci-Tandogan G, Castle V, Fernandez-Gonzalez R. Myosin cables control the timing of tissue internalization in the Drosophila embryo. Cells Dev. 2021 July 13:203721.

Cardiac progenitors expressing GFP-MoesinABD under the hand promoter (cardiac specific) were imaged as they migrate to form the primitive heart tube. Diffraction-limited (left) and SRRF reconstruction (right) images are shown. Bursts of 100 raw images were acquired at 50 FPS, with one image burst acquired every 5 s. 100 raw images were used to reconstruct each SRRF image. SRRF reconstructions used the default parameter values of 0.5 pixel ring radius, 8 axes, and a value of 5 for radiality magnification, using the temporal radiality average method (TRA) to calculate temporal correlations. The same images were averaged to generate diffraction-limited data.

Source: Scepanovic G, Florea A, Fernandez-Gonzalez R. Multiscale In Vivo Imaging of Collective Cell Migration in Drosophila Embryos. Methods Mol Biol. 2021; 2179:199-224.

Epidermal cells expressing mCherry:mito (left: magenta, and center) and injected with H2DCFDA, a membrane-permeable ROS dye that upon oxidation is converted into the fluorescent DCF (left: green, and right). Red lines denote wound sites. Images were acquired every 30 s for 26.5 min. Time after wounding is shown. Anterior left, dorsal up.

Source: Hunter MV, Willoughby PM, Bruce AEE, Fernandez-Gonzalez R. Oxidative stress orchestrates cell polarity to promote embryonic wound healing. Dev Cell. 2018 Nov 5;47(3):377-387.

Wound healing simulations with a heterogeneous myosin distribution and no myosin turnover (left), with tension-based myosin stabilization (centre-left), with strain-based myosin recruitment (centre), or with strain and tension-dependent myosin dynamics (centre-right); or with a homogeneous myosin distribution and strain and tension dependent myosin dynamics (right). Colour indicates interfacial tension in nN based on myosin levels (see Fig. 4 for scale). The simulation time step was 2 s for 20 min. Time is with respect to the onset of wound closure. Anterior left, dorsal up.

Source: Zulueta-Coarasa T, Fernandez-Gonzalez R. Dynamic force patterns promote collective cell movements during embryonic wound repair. Nature Physics 2018 14:750–758

Germband cells expressing Gap43:mCherry at the final stages of axis elongation. Red circles represent watershed seeds. Green shows segmentation and tracking results. A stack was acquired every 15 s. Anterior left, ventral centre.

Source: Wang MFZ, Hunter MV, Wang G, McFaul C, Yip CM, Fernandez-Gonzalez R. Automated cell tracking identifies mechanically oriented cell divisions during Drosophila axis elongation. Development 2017 144: 1350-1361

Epidermal cells expressing MRLC:GFP (left, green; centre) and E-cadherin:mTomato (left, magenta; right) in a wounded embryo. White arrowheads indicate photobleaching sites adjacent (top) or far (bottom) from the ablation site. Anterior left, dorsal up.

Source: Kobb AB, Zulueta-Coarasa T, Fernandez-Gonzalez R. Tension regulates myosin dynamics during Drosophila embryonic wound repair. J Cell Sci 2017 130: 689-696

Germband cells in embryos expressing E-cadherin:GFP (green) and myosin:mCherry (magenta) under sham irradiation (left) or upon wounding and apical constriction of the cells anterior and posterior to a multicellular vertex (right). Arrows indicate resolving multicellular vertices. A stack was acquired every 3 s. Time is indicated as min:s. Anterior left, dorsal up.

Source: Yu JC, Fernandez-Gonzalez R. Local mechanical forces promote polarized junctional assembly and axis elongation in Drosophila. eLife 2016 Jan 9;5.

Epidermal cells expressing ubi–E-cadherin:GFP (green) and myosin:mCherry (red) in a control embryo injected with 50% DMSO (left) or 50 mM dynasore (right). Images were acquired by time-lapse confocal microscopy using a spinning disk confocal microscope (Revolution XD; Andor Technology). A stack was acquired every 30 s for 44 min. Time after wounding is shown. Anterior left, dorsal up.

Source: Hunter MV, Lee DM, Harris TJC, Fernandez-Gonzalez R. Polarized E-cadherin endocytosis directs actomyosin assembly during embryonic wound repair. J Cell Biol 2015 Aug 31;210(5):801-16.

Epidermal cells expressing myosin:mCherry (left) and Abl:GFP (right). Time after wounding is indicated. Anterior left, dorsal up.

Source: Zulueta-Coarasa T, Tamada M, Lee EJ, Fernandez-Gonzalez R. Automated multidimensional image analysis reveals a role for Abl in embryonic wound repair. Development. 2014 Jul;141(14):2901-11.