Fig. 1. During ampA– strain development, expression of the pspD reporter gene is induced prematurely and prespore reporter activity is observed in cells in regions normally occupied by prestalk cells. PspD reporter expression patterns are shown for wild-type (left) and ampA– structures (right) for the following developmental stages: (A,B) tight mounds (10 hours development), 4 hours staining; (C,D), tips (13.5 hours development), 2.5 hours staining; (E,F), early culminants (18 hours development), 2.5 hours staining. Arrows indicate regions of the structures where prestalk cells are usually found. (G) Quantitation of the number of cells expressing the pspD reporter in wild-type and ampA null structures harvested at 14 hours of development. Developing structures were dispersed to single cells, fixed, stained and counted as described in the Materials and Methods.
