Intercellular adhesion and formation of aggregates in normal and Talpid-3 mutant chick limb mesenchyme

It is demonstrated, using the Couette viscometer method, that talpid-3 mutant chick wing mesenchyme cells are more adhesive to one another than are normal cells. The relation of this to differences in the size and shape, and the internal architecture, of aggregates produced in rotation cultures of these cells was investigated. Sequences of sections through aggregates in all stages of formation, from 2-cell aggregates up to those with large cell numbers, were prepared. These confirm the theoretically predicted relationships among adhering cells which would produce the observed small, spherical talpid-3 aggregates and the larger, unevenly shaped normal aggregates. The cell contacts are further analysed with electron micrographs.