Download The accompanying Excel spread sheet contains four columns of

The accompanying Excel spread sheet contains four columns of data, presented as
expression ratios.
The first is a control with the Cy3-labeled wild-type (CU1065) cDNA cohybridized with
Cy5-labeled wild-type cDNA. The following three slides are cohybridization of cDNA
prepared from wild-type (CU1065) versus cDNA prepared from the isogenic sigW
mutant strain. The data are sorted in terms of increasing ratios based on the first
experimental data set. The genes near the top in this arrangement are those most
decreased in expression in the sigW mutant, and therefore most likely to be targets for
sigW-dependent transcription. Genes near the bottom of the spreadsheet, for which valid
ratios were obtained, are those that are up-regulated in the sigW mutant. Many of these
genes belong to the sigma-B-dependent general stress response.
Blanks indicate that no ratio was calculated as the signals detected for that gene were at
or near background. Ratios calculated when one signal (either the Cy3 or the Cy5
channel) was near background are flagged in the columns labeled “Fluor. w/in 1SD of
Background.” These ratios should be considered approximate and are not included when
computing average ratios of induction. Note that these arrays contain ~90% of the
annotated B. subtilis ORFs as described in Methods and Materials.
Note that individual gene values can be obtained using the “Find” function of Microsoft
Excel and the data can easily be re-sorted to generatean alphabetic list if desired.
J. Helmann
1-21-02