Visualizing F-Actin Structure in Developing Zebrafish Zygotes to Supplement Viscoelastic Measurements

Abstract

The cell has developed an elaborate cytoskeleton that can undergo dramatic rearrangements in order to grow, divide, or move. In the one-cell stage of the zebrafish embryo, the cytoskeleton completely reorganizes to form the cellular compartment. We want to understand the link between the morphological structure of the cell's cytoskeleton and the mechanical properties of the cell. That is, we want to find out if rearrangements of filamentous cytoskeletal proteins like F-actin and microtubules lead to changes in cellular viscosity or elasticity. To do this, we need to correlate images of cytoskeletal structures with mechanical measurements. In this part of our project, we imaged the rearrangement of the F-actin network during cytoskeletal formation in the one-cell stage of the zebrafish embryo. These images will complement microrheology measurements of the viscoelasticity of the cell. To take images, we fixed the embryo and labeled the cellular F-actin with the dye phalloidin. We then imaged the mounted embryos on a confocal microscope to see the F-actin organization. Our images show that just before cellular cleavage, the F-actin has collected at the cellular periphery, similar to previous work.