Pex1 is not required for de novo formation of peroxisomal membranes. (A) Galactose-controllable PEX19 strains expressing Pex13-GFP and Pex11-mRFP from their endogenous promoters (on plasmids) were grown on raffinose (top) or galactose medium for the times indicated. The Pex11-mRFP signal was weak and was enhanced strongly to show localization. (B) WT, pex3Δ, and pex19Δ cells expressing Pex11-mRFP from its endogenous promoter on plasmid were grown to log phase and stained with MitoTracker green. (C) WT and pex19Δ cells expressing Pex13-GFP and Pex3-mCherry (Pex3-mCH) from endogenous promoters (on plasmids) were grown to log phase. Bars, 5 µm.