FIGURE 4: Hypoxic treatment boosts HAC1-mRNA splicing even in ρ^o mutant cells.(A) and (B) Wild-type BY4742 cells and the congenic ρ^o mutant were cultured (or ER-stressed by the indicated concentrations of DTT for 30 min) under the aerobically shaken condition at 30°C in YPD, and were checked for optical culture density and HAC1-mRNA splicing. (C) The ρ^o mutant cells used in panels A and B were cultured and ER-stressed as shown in Fig. 2A, and were checked for HAC1-mRNA splicing. n.s. (not significant): p > 0.05, *: p < 0.05, **: p < 0.01.