Figure 5.

Distribution of mef2A^-mutant cells, expressing prestalk or prespore markers, in developmental structures formed in combination with wild-type cells. Wild-type (AX4) or mef2A^- mutant (mef2A^-) cells were mixed in a 4:1 proportion with pools of cells transfected with reporter vectors (AX4::lacZ, mef2A::lacZ) expressing lacZ under the control of the prestalk-specific ecmB promoter (ecmB::lacZ) or the prespore-specific pspA promoter (pspA::lacZ). Cell mixtures were allowed to develop on nitrocellulose filters, slugs or culminant structures were collected and lacZ expression was determined by Xgal hydrolysis. The two upper rows of pictures show the distribution of cells expressing the prestalk ecmB promoter, and the two lower rows show those expressing the pspA prespore promoter. The structures were stained with eosin and observed under a stereomicroscope. Scale bar: 0.2 mm.