Table 1. Binding of Sin3 to the CLN2 promoter in swi4 and swi6 mutants: p-values.

Strain	WT	swi4	swi6	Negative Control
WT		0.5	0.004	0.0003
swi4			0.0008	0.00001
swi6				0.1

p-Values for a test of a difference of means for ChIP analysis of the CLN2 promoter fragment containing the SBF sites in strains containing tagged Sin3. The strains are wild-type (WT), swi4, and swi6 strains all carrying tagged SIN3, and an untagged SIN3 strain as a control. The experiment was done ten independent times in each strain. For each experiment, PCR-amplified DNA from ChIP was placed in a tube with a coded label by one investigator (HYW), and given to a second investigator (LBC). PCR fragments were separated by gel electrophoresis, and the ratio of the “sbf” band to the mean of the “up” and “dyn” bands (see Figures 4 and 5) was determined using image analysis software. Once ratios were determined, the label code was broken, and ratios were assigned to their genotypes. One-tailed t-tests were done to calculate p-values of the differences of the means of the logarithms of the ratios (Log ratios were used so as to produce a normal distribution). These p-values are shown above. For example, Sin3 does not appear to ChIP to the CLN2 promoter in a swi6 mutant, and the difference between the swi6 mutant and the wild-type in this regard has a p-value of 4×10⁻³. Two typical (median) experiments were chosen from each of the ten sets of experiments and shown in Figure 5.