May 3, 2019

Florence Giger

12.15-12.30 Florence Giger

‘Cellular and mechanical mechanisms driving forebrain neurulation’

Neural tube closure is a crucial morphogenetic event in development. Anteriorly, telencephalic cells converge towards the midline above eye progenitors that maintain a cohesive state before moving outwards to form the optic vesicles. Although the patterning mechanisms giving rise to telencephalon and eye identity have been described, how these decisions translate into complex morphogenetic behaviours is still unknown.
I am taking advantage of the amenability of the zebrafish embryo to live imaging to understand the mechanisms underlying forebrain neurulation. High resolution time-lapse images have revealed that the zebrafish eye field is formed by complex folding of the anterior neural plate. This makes it both original as the rest of the neural tube adopts a very different behaviour, and universal as the zebrafish anterior neural plate appears to be epithelial-like and thereby closer to other vertebrate models than what was previously believed.
Myosin accumulates both at the midline and at the folding sites, forming a string around the neural plate that closes in a hairpin shape as neurulation proceeds. Disruption of this Myosin structure will help determine its role for the organisation of the forebrain. Previous work has identified zebrafish mutants with forebrain neurulation defects. Comparative analysis of Myosin organisation in addition to cell movements and dynamics in wild-type and mutant embryos will be of crucial importance to understand forebrain morphogenesis.
Combination of high-resolution live imaging, genetics, biomechanics and functional analyses are deployed to understand early forebrain morphogenesis and identify core principles of synergy between biomechanical and molecular control of organ formation in vertebrates.