Figure 4.

Analysis of the progression of replication forks that are codirectional with transcription. (A) 2D-gel analysis of the ScaI restriction fragment covering the leu2 repeats in the GAL-OUT construct isolated from cells grown in glucose (Glu; transcription OFF) or galactose (Gal; transcription ON). (B) 2D-gel electrophoresis of the SalI–NdeI restriction fragment covering the leu2 repeats in the GAL-OUT and HHF-OUT constructs isolated from cells grown in galactose or glucose, respectively. An open arrow indicates a weak transcription-dependent RFP in the HHF-OUT construct. The asterisks indicate the expected position corresponding for the RFP at the leu2Δ3′ repeat as detected in the GAL-IN and HHF-IN constructs (Figure 3). Note that the signal accumulated in the inflection points of the Y-arcs in the GAL-OUT construct is the consequence of the overlapping left and right arcs, and does not correspond to a true RFP, since it does not change its position in the overlapping fragments.