LIQUID PROPERTIES OF EMBRYONIC-TISSUES - MEASUREMENT OF INTERFACIAL-TENSIONS

The flow of embryonic tissues during morphogenesis has been ascribed t o tissue interfacial tensions arising from cell adhesion. Testing this explanation requires the demonstration that tissue interfacial tensio ns are measurable physical quantities. We describe a device that conti nuously records all parameters necessary to determine the tensions of living tissues at the interface with the surrounding medium. We monito r the relaxation of an imposed stress in two embryonic tissues, measur e their interfacial tensions, and demonstrate that these are consisten t with these tissues' mutual spreading behavior.