Cell migration dynamics inside zebrafish embryo

MIÑO, GASTÓN; SAMPEDRO, MARIA FLORENCIA; SIGOT, VALERIA

Congreso; II Brazil-Argentina Microfluidics Congress; 2019

During tissue morphogenesis, collective cell migration represents an excellent microfluidic biological model, where, the motion of the tissue can be seen as a continuum in which the cell displacement introduces changes in their surroundings. The tissue cohesion is maintained mainly by the cell-adhesion molecule, Epithelial-cadherin (E-cadh), localized at adherens junctions (AJs). Dynamic remodeling of AJs is crucial to coordinate collective cell movements during animal embryogenesis. The posterior lateral line primordium (pLLP) in zebrafish is a powerful model system to study guided migration and epithelial morphogenesis, being amenable to live imaging. By combining high-resolution microscopy in zebrafish embryos expressing E-cadh-GFP and automatic segmentation algorithms in 4D, we implemented a routine to analyze E-cadh distribution in vivo during pLLP migration. At every time point analysed we found a polarized distribution of E-cadh expression along the pLLP, with lower expression in cells at the leading front and at higher levels in cells at the trailing end. During one hour time lapse the total area of the pLLP did not change significantly and the global displacement measured was ~50 µm at 24°C. We proposed that this patterned E-cadh distribution at the front and trailing regions of pLLP may be related to differences in local velocity of the cells within those regions. To test this we are currently working to obtain instantaneous velocity fields from the segmented image sequences by using PIV (Particle Image Velocimetry) analysis, a technique routinely used in microfluid dynamics with unexplored potential to understand morphogenetic movements.