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VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Shaping the fly wing
DTSTART:20161114T110000
DTEND:20161114T123000
DTSTAMP:20260407T211012Z
UID:5a00ca16cc484be8a25b92c561e4053c5e2584e4d10920d904565b23
CATEGORIES:Conferences - Seminars
DESCRIPTION:Wing of the fruit fly develops from an epithelial tissue calle
 d imaginal disc. During development a fly goes trough a larval development
 al stage during which the wing mostly grows and trough a pupal stage when 
 the wing tissue reshapes to obtain a shape similar to adult wing. How do c
 ellular processes and mechanical stresses lead to the proper reshaping of 
 the wing at different stages of development?\nWe observe large scale tissu
 e flows in vivo over 16 hours of pupal wing development and track majority
  of wing cells during this time interval. This allows to identify cellular
  processes: cell division\, cell extrusion and T1 transitions (neighbour e
 xchanges) and to quantify contributions of each cellular process to the ov
 erall tissue flow. We find a dramatic interplay of cell shape changes and 
 T1 transitions and we construct a hydrodynamic theory of tissue flows trea
 ting coarse-grained cell scale quantities as observable hydrodynamic field
 s. Experimental measurements imply the existence of active T1 transitions 
 which do not relax but rather increase the elongation of cells in the tiss
 ue\, as well as memory effects which lead to oscillations. Rheological dia
 gram describing flow of such tissue with memory includes an effective iner
 tial element called ‘inerter’. We then construct a simple model of the
  pupal wing which can capture the main features of wing reshaping in the w
 ild type wing as well as in mechanical and genetic perturbations of the bo
 undary conditions imposed on the wing tissue.\nCurrently we are studying b
 ehaviour of larval imaginal discs in a culture medium. Interestingly\, we 
 see indications of the active T1 transitions oriented radially around the 
 tissue center and we are investigating consequences such T1 transitions co
 uld have on the mechanics of the tissue.
LOCATION:BSP 233 Auditoire III
STATUS:CONFIRMED
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