Shaping the fly wing
Event details
| Date | 14.11.2016 |
| Hour | 11:00 › 12:30 |
| Location |
BSP 233 Auditoire III
|
| Category | Conferences - Seminars |
Wing of the fruit fly develops from an epithelial tissue called imaginal disc. During development a fly goes trough a larval developmental 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 cellular processes and mechanical stresses lead to the proper reshaping of the wing at different stages of development?
We observe large scale tissue 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 exchanges) and to quantify contributions of each cellular process to the overall tissue flow. We find a dramatic interplay of cell shape changes and T1 transitions and we construct a hydrodynamic theory of tissue flows treating coarse-grained cell scale quantities as observable hydrodynamic fields. Experimental measurements imply the existence of active T1 transitions which do not relax but rather increase the elongation of cells in the tissue, as well as memory effects which lead to oscillations. Rheological diagram describing flow of such tissue with memory includes an effective inertial element called ‘inerter’. We then construct a simple model of the pupal wing which can capture the main features of wing reshaping in the wild type wing as well as in mechanical and genetic perturbations of the boundary conditions imposed on the wing tissue.
Currently we are studying behaviour 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 could have on the mechanics of the tissue.
We observe large scale tissue 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 exchanges) and to quantify contributions of each cellular process to the overall tissue flow. We find a dramatic interplay of cell shape changes and T1 transitions and we construct a hydrodynamic theory of tissue flows treating coarse-grained cell scale quantities as observable hydrodynamic fields. Experimental measurements imply the existence of active T1 transitions which do not relax but rather increase the elongation of cells in the tissue, as well as memory effects which lead to oscillations. Rheological diagram describing flow of such tissue with memory includes an effective inertial element called ‘inerter’. We then construct a simple model of the pupal wing which can capture the main features of wing reshaping in the wild type wing as well as in mechanical and genetic perturbations of the boundary conditions imposed on the wing tissue.
Currently we are studying behaviour 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 could have on the mechanics of the tissue.
Practical information
- General public
- Free
Organizer
- Prof. Matthieu Wyart
Contact
- Corinne Weibel