Figure 3.

A. SWI5 is required for PCL9 transcription. Densitometric quantitation of a Northern blot analysis using mRNA from exponentially growing wild-type (DTY7), swi5Δ (DTY87), ace2Δ (DTY91), and swi5Δace2Δ (DTY92) strains. Blots were hybridized with probes from PCL2 and SIC1 and normalized to ACT1 as a loading control. (B) Effect of deletion of SWI5 on the cell cycle regulation of PCL2 and PCL9 transcription. Cultures of swi5Δ strains containing either the plasmid YIpSWI5 or control plasmid YIplac211 were synchronized using α-factor, and samples were taken for Northern blot analysis (Toyn et al., 1997). The Northern blot was quantitated by densitometry and normalized to the level of actin mRNA detected on the same blot. The first sample on the autoradiograph is from log-phase cells before addition of α-factor and is not shown in the quantitations. Quantitations of transcript levels from the SWI5 (solid circles) and the swi5Δ experiment (open circles) are compared. The data points relating to the percentage buds and divided chromatin were described by Toyn et al. (1997).