Figure 1.

a- and b-Dependent Expression of clp1.

(A) and (B) Analysis of clp1 expression after induction of compatible (strain AB31) and incompatible (strain AB32) combinations of bE and bW. Samples were taken before and 2, 5, and 12 h after induction with arabinose.

(A) Real-time quantitative RT PCR analysis. clp1 expression was measured relative to the constitutively expressed gene for peptidylprolyl isomerase (ppi; um03726). Shown are the mean values and standard deviation of four technical replicates.

(B) RNA gel blot analysis; 10 μg of total RNA was loaded per lane. As a loading control, the filter was stained with methylene blue to visualize blotted rRNA.

(C) Wild-type strains FB1, FB2, FB6a, and FB6b and the diploid strains FBD11 and FBD12-3 were grown for 48 h on complete medium containing charcoal as indicated, prior to RNA isolation. FB1 was treated with pheromone a2 for 75 min. The probe used for hybridization covered 744 bp of the 5′-region of the clp1 ORF. Note that only in combinations with an active b1/b2 combination is the 1.6-kb clp1 transcript visible; the smaller 0.6-kb transcript is formed in combinations with an active a1/a2 combination.