Measuring cell adhesion forces of primary gastrulating cells from zebrafish using atomic force microscopy

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Vertebrate gastrulation involves germ layer formation and separation, driven by cells acquiring specific adhesive properties.
• Wnt signals are hypothesized to modulate inter-germ layer adhesion, but direct evidence is lacking.

Purpose of the Study:

• To investigate the role of Wnt11 signaling in the adhesion of zebrafish mesendodermal progenitor cells to fibronectin.
• To quantitatively measure single-cell adhesion forces during gastrulation using atomic-force microscopy.

Main Methods:

• Developed a single-cell adhesion assay using atomic-force microscopy (AFM) to quantify detachment force and work.
• Compared adhesion of wild-type and slb/wnt11 mutant zebrafish mesendodermal progenitors to fibronectin-coated substrates.
• Utilized RGD peptides to assess the involvement of integrins in cell adhesion.

Main Results:

• Wnt11 signaling is essential for mesendodermal progenitor cell adhesion to fibronectin.
• slb/wnt11 mutant cells exhibited significantly reduced adhesion force and work compared to wild-type cells.
• Integrins mediate the adhesion of these cells to fibronectin, as indicated by inhibition studies.

Conclusions:

• Wnt11 plays a critical role in regulating cell adhesion to the extracellular matrix during gastrulation.
• AFM is a valuable tool for quantitatively assessing single-cell adhesion in developing embryos.
• This study provides direct evidence for Wnt11's function in modulating cell adhesion at the single-cell level.