FIG. 6.

Genes expressed in prestalk cells only during culmination. We found 23 genes which gave very little in situ signal at the slug stage. SSE634 is a representative of 14 of these genes that were subsequently expressed at high levels in PstO cells (a to d). Another nine genes, exemplified by SSG721, failed to show cell type specificity at the slug stage but were expressed in cells within the top of the stalk tube during culmination. Their mRNAs could be seen in vacuolized cells near the top of the stalk tube (e to h). (a and e) Slug stage; (b and f) Mexican hat stage; (c and g) early culmination stage; (d and h) late culmination stage.