Analysis of the cell adhesion mechanism using somatic cell hybrids. I. Aggregation of hybrid cells between adhesive V79 and non-adhesive Ehrlich's ascites tumour cells.

V79 Chinese hamster cells dissociated with 1 nm EDTA retain 2 kinds of cell adhesion mechanisms, one dependent on Ca2+ and the other independent of Ca2+. Ehrlich's ascites tumour (EAT) cells are provided with neither Ca2+-dependent nor CA2+-independent mechanisms. Studies on the aggregation of cells of 25 different hybrid clones obtained by fusing these 2 lined cells revealed the following points with regard to adhesive properties of hybrid cells. (1) The activity of the Ca2+-independent mechanism was lower in most hybrid clones than in parental V79 cells. (2) There were a few hybrid clones whose Ca2+-dependent mechanism activity was lower than in V79 cells. In these clones, the Ca2+-independent mechanism was also less active than the parental cells. (3) A hybrid clone with reduced Ca2+-dependent mechanism activity only was not found. (4) All the hybrid clones have at least one set of chromosomes derived from V79. (5) The number of chromosomes derived from EAT cells tended to be less in hybrid clones with lower aggregative ability. These results can be explained by assuming that the activity of the Ca2+-independent and Ca2+-dependent mechanisms of V79 cells may be differently inhibited by genes contained in EAT cells.