A developmentally regulated glycoprotein implicated in adhesion of Dictyostelium slugs in predominantly in prespore cells

Prestalk and prespore cells were isolated from Dictyostelium discoideum slugs after [1‐ 14 C]acetate labelling and the distribution of developmentally regulated plasma membrane proteins between the two cells types determined. A glycoprotein ( M r 95 000) involved in slug cell adhesion, and all the developmentally regulated plasma membrane proteins synthesized during the latter half of development, were predominantly associated with prespore cells. Sorting‐out patterns in slugs indicated that cell adhesion is greater between prespore than prestalk cells. The M r 95 000 glycoprotein may be part of the cell recognition and sorting mechanisms involved in fruiting body formation. Actin and myosin synthesis ceased in prespore but not prestalk cells. When slugs were disaggregated, synthesis of these two proteins was reactivated in prespore cells, but synthesis of developmentally regulated plasma membrane proteins was not induced in prestalk cells. Actin and myosin synthesis was activated in prespore cells following disaggregation.