Dr Bénédicte Sanson
Lecturer and Research group leader Tel: +44 (0)1223 333893, Fax: +44 (0)1223 333840, E-mail: bs251@cam.ac.uk
Morphogenesis of early embryos: in vivo mechanisms for cell sorting and collective cell movement
Cell sorting: functional analysis of putative Myosin II
regulators
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.
Collective cell movements: whole volume imaging of
gastrulation in live embryos
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 (in collaboration with
Richard Adams's group, PDN).
Research team
Claire Lye (Herchel Smith Postdoctoral Fellow)
Huw Naylor (MPhil Student)
Rob Tetley (Wellcome Trust Program in Developmental Biology PhD Student)
Jose Urbano (Spanish Government Postdoctoral Fellow)
Previous lab members
Bruno Monier, Lucy Butler, David Welchman, Nicola Lawrence, Dhia Chandraratna, Sabrina Desbordes, Caroline Fabre
Sources of funding
Wellcome Trust, Newton Trust, HSFP
Recent research articles
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.
- Paper evaluated as "exceptional" by Faculty1000
- Highlighted in Martin AC, Wieschaus EF, Nat Cell Biol, 2010 12: 5-7; Baumann K, Nature Reviews in Molecular Cell Biology, 2010, 11: 4-5; The Scientist, 2010, 24: 67; Editor's choice in Development.
Butler, L.C., Blanchard, G.B., Kabla, A.J., Lawrence, N.J., Welchman, D.P., Mahadevan, L., Adams, R.J., and Sanson, B. (2009) Cell shape changes indicate a role for extrinsic tensile forces in Drosophila germ-band extension. Nat Cell Biol 11: 859-864.
- Paper evaluated as "must read" by Faculty1000
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.
- Above two papers were awarded the international 2010 Drosophila Image Award
Recent invited reviews
St Johnston, D., and Sanson, B. (2011) Epithelial polarity and morphogenesis. Curr Opin Cell Biol in press.
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.
Other selected publications
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, Bénédicte Sanson, Huw Naylor, Rob Tetley, Jose Urbano, 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)



