Studying the relationship between the size and the #anatomy and #physiology of #living organisms has proven useful in order to decipher what the key #physical constraints are that apply to them.

Here we consider both variations of #cellSize, using a drug that blocks mitosis without inhibiting growth, and of the interactions with the substrate, by considering the different stages of the quasi-static process of #cellSpreading, but also by using confinement, and thus presenting more than one substrate for the #cell to spread on. The fibroblasts used in this study present the archetypal shape of a cell spreading on a substrate, with a central cell body which, while flattening, retains a spherical cap shape, and is surrounded by a flat #lamella. We show that this shape is preserved isometrically between the cell size and cell confinement conditions. Moreover, the length ratio that characterises it establishes early during spreading, at the time when #focalAdhesion with the substrate develop. These #adhesion patches also collectively follow an isometric scaling with respect to cell spread area, in spite of having individually a shape, size and density which is insensitive to the global cell shape. We show that this isometry follows from the restriction of the distribution of focal adhesions to the flat lamella.

Since adhesion distribution is crucially important for maintaining the cell shape, we suggest that the observed allometry may be important for the cell to face the #mechanical challenges of physiological function.

⬆️ New #preprint ! ⬆️

#Cells seem to like to keep their proportions. All thru the process of spreading on a substrate, we find conserved ratios in size of #lamella (under which cell #FocalAdhesion patches grow) and cell body. We show that this requires the interplay of some global regulation (based on #mechanical interactions?) with local processes.