Tel: +44 (0)1223 333893, Fax: +44 (0)1223 333840, E-mail: email@example.com
We have recently demonstrated using Chromophore-Assisted Laser Inactivation (CALI) in live Drosophila embryos, that a pool of Myosin II which forms cables at compartmental boundaries, is required for cell sorting at these boundaries (Monier et al, 2010, Nature Cell Biology, vol 12: 60-5). Using live imaging, we showed that this supracellular cable of Myosin II is required to stop dividing cells in one compartment from invading the adjacent compartment. To understand how actomyosin barriers form and function, we have performed a screen to find YFP-tagged proteins localising at these barriers. We are now testing the role of these proteins in compartmental cell sorting and in actomyosin barrier formation.
We have mapped the collective cell movements during Drosophila embryo gastrulation and found that an axial force deforms the ectodermal cells (Butler et al, 2009, Nature Cell Biology, vol 11: 859-64). This gives us an unprecedented opportunity to analyse how active cell behaviours and extrinsic forces mechanistically interact to shape embryos. We have evidence that mesoderm invagination might provide the axial force that propels ectoderm convergence and extension. Analysing the relationship between these two morphogenetic movements will require characterising cell shapes in 3D (using cell membrane and nuclei labelling) and mapping their positions in the whole embryo volume, as a function of developmental time (see Collaborators).
Claire Lye (Herchel Smith Postdoctoral Fellow) website
Jose Urbano (Postdoctoral Research Associate) website
Huw Naylor (Research Assistant and Lab Manager)
Rob Tetley (Wellcome Trust Program in Developmental Biology PhD Student)
Bruno Monier, Lucy Butler, David Welchman, Nicola Lawrence, Dhia Chandraratna, Sabrina Desbordes, Caroline Fabre
Wellcome Trust, BBSRC, Newton Trust
Monier, B., Pelissier-Monier, A., Brand, A.H., and Sanson, B. (2010) An actomyosin-based barrier inhibits cell mixing at compartmental boundaries in Drosophila embryos. Nat Cell Biol 12: 60-65. pdf
Butler, L.C., Blanchard, G.B., Kabla, A.J., Lawrence, N.J.,
Mahadevan, L., Adams, R.J., and Sanson, B. (2009) Cell shape changes
role for extrinsic tensile forces in Drosophila germ-band extension. Nat
Cell Biol 11: 859-864. pdf
Blanchard, G.B., Kabla, A.J., Schultz, N.L., Butler, L.C., Sanson, B., Gorfinkiel, N., Mahadevan, L., and Adams, R.J. (2009) Tissue tectonics: morphogenetic strain rates, cell shape change and intercalation. Nat Methods 6: 458-464. pdf
St Johnston, D., and Sanson, B. (2011) Epithelial polarity and morphogenesis. Curr Opin Cell Biol 23:540-546. pdf
Lye, C., and Sanson, B. (2011) Tension and epithelial morphogenesis in Drosophila early embryos. Curr Top Dev Biol 95: 145-187.
Monier, B., Pélissier-Monier, A., and Sanson, B. (2011) Establishment and maintenance of compartmental boundaries: role of contractile actomyosin barriers. Cell Mol Life Sci 68: 1897-910.
Chandraratna, D., Lawrence, N., Welchman D., and Sanson, B. (2007) An in vivo model of apoptosis: linking cell behaviours and caspase substrates in embryos lacking DIAP1. J Cell Sci 120: 2594-2608.
Desbordes, S.C., Chandraratna, D., and Sanson, B. (2005) A screen for genes regulating Wingless distribution in Drosophila embryos. Genetics 170: 749-766.
Sanson, B. (2004) Do glypicans play a role in Wingless signalling in Drosophila? Development 131: 2511-2513.
Desbordes, S., and Sanson, B. (2003) The glypican Dally-like is required for Hedgehog signalling in the embryonic epidermis of Drosophila. Development 130: 6245-6255.
Sanson, B. (2001) Generating patterns from fields of cells: examples from Drosophila segmentation. EMBO Rep 2: 1083-1088.
Sanson, B., Alexandre, C., Fascetti, N., and Vincent, J-P. (1999) engrailed and hedgehog make the range of Wingless asymetric in Drosophila embryos. Cell 98: 207-216.
Greaves, S., Sanson, B., White, P., and Vincent, J-P. (1999) A screen to identify genes interacting with armadillo, the Drosophila homologue of Beta-Catenin. Genetics 153: 1753-1766.
Sanson, B., White, P., and Vincent, J-P. (1996) Uncoupling Cadherin-based adhesion from wingless signaling in Drosophila. Nature 383: 627-630.
Lawrence, P.A., Sanson, B., and Vincent, J-P. (1996) Compartments, wingless and engrailed: patterning the ventral epidermis of Drosophila embryos. Development 122: 4095-4103.
Above: Current research group: from left to right, Jose Urbano, Bénédicte Sanson, Huw Naylor, Rob Tetley, Claire Lye.
Above: Time-lapse movie showing a parasegmental boundary in a MRLC-GFP embryo, with the MyoII cable coloured artificially in green. Dividing boundary cells (stars) deform the MyoII cable (arrows) and transiently invade the opposite compartment. After division, the daughter cells always go back to their compartment of origin and the boundary straightens out (Movie S2 from Monier et al, 2010, Nature Cell Biology, vol 12: 60-5).
Above: Live Drosophila embryo filmed during gastrulation, with the apical cell membranes labelled with Green Fluorescent Protein and automatically tracked through time. In this movie frame, the multicoloured tracks represent the trajectory of the centre of each cell over the previous four minutes (2010 Drosophila Image Award)