Figure 4.

Distribution of prestalk and prespore cells in mef2A^-mutant developmental structures. Wild-type (AX4) and mef2A^- mutant cells (mef2A^-) were transfected with reporter vectors where lacZ was expressed under the control of the promoter region from the prestalk-specific genes ecmA (ecmA::lacZ) and ecmB (ecmB::lacZ) or the prespore-specific gene pspA (pspA::lacZ). Pools of transfected cells were placed on nitrocellulose filters to induce multicellular development. Structures were collected at the finger, slug and culminant stages of development, and lacZ expression was determined by histochemical Xgal staining. Pictures were taken using a Leica stereomicroscope, after counter-staining with eosin. Scale bar: 0.2 mm.