Fig. 4. The global pattern of gene expression during sporulation.
(A) The genes that showed the most significant induction or
repression during sporulation (a total of 1,116) were ordered so that genes
with similar expression patterns were grouped together and so that the order
roughly reflected the time of first induction or repression. Changes
in mRNA concentrations for each gene, relative to those in cells immediately
prior to transfer to sporulation medium, are graphically displayed with a
color to represent the quantitative changes as described in Figure 3. Time
after transfer to sporulation medium is shown on the horizontal axis.
(B) A set of representative genes was chosen from each of these seven expression
patterns, and average expression profiles for each set were calculated.