February 19, 2014

It will take cell biologists an eternity to understand how cells function in a dish. It will take developmental biologists even longer to understand how cells function within a developing organism. Today’s image is from a paper describing the use of liquid droplets as cell biological crash test dummies to determine cell-generated forces within living tissue.

The development of an organism and the generation of its organs depend on mechanical forces that can move cells and groups of cells. There are many techniques that have been helpful in understanding these forces, but these techniques have not been applicable for measuring forces in three dimensional living tissue (or, in the case of laser ablation, have only provided relative force measurements). Campàs and colleagues have just published a paper describing the clever use of oil microdroplets to measure force within living tissues and organs. These spherical microdroplets are a similar size as cells, are fluorescently labeled, and display cell surface adhesion receptors. After these microdroplets are injected into tissue, their deformation by surrounding cells exerting mechanical stress can be measured and quantified. The images above show a microdroplet (white arrow, top) embedded in an incisor tooth bud of a mouse embryo (E13.5). Higher magnification views of the microdroplet (bottom row) show the pixel-resolution contour of the droplet (middle). The higher curvature regions (arrows, right image) correlate with cell-cell junctions of adjacent cells. 

Campàs O, Mammoto T, Hasso S, Sperling RA, O'Connell D, Bischof AG, Maas R, Weitz DA, Mahadevan L, & Ingber DE (2014). Quantifying cell-generated mechanical forces within living embryonic tissues. Nature methods, 11 (2), 183-9 PMID: 24317254
Adapted by permission from Macmillan Publishers Ltd, copyright ©2014