FIG. 3.

Northern blot analysis of KHT1- and KHT2-specific transcription in wild-type (WT) and kht mutant cells. K. lactis strain JA6 and congenic kht disruption mutants were grown to the exponential phase in YNB minimal medium containing 2% glucose (glu) (lanes 1 to 4) or 3% glycerol (gly) (lanes 5 to 8), and poly(A)⁺ RNA was isolated. Five micrograms of poly(A)⁺ RNA samples was fractionated by electrophoresis on a 1.3% agarose gel in the presence of formaldehyde. Plasmid pJW10–23 carrying the entire KHT-KHT2 locus (38) (A) and a small KHT1 5′-specific probe (HpaI-XhoI fragment of pJW10-7 [38] [B]) were used as probes. An HHT1 (histone H3) probe was added as a loading control. Note that in panel A, a weak kht1::ura3 fusion transcript overlaps with the HHT1 signal in lanes 2 and 7. In panel B, the two probes were applied sequentially (top and middle panels). A longer exposure of the top panel is shown at the bottom to visualize the weak cross-hybridizing transcript X.