FIG. 2.

Effects of introns and codon modification on hygromycin B mRNA accumulation. The recipient S. commune ΔSC3 strain (r, lane 16) was transformed with the modified hygromycin B gene (lanes 1 to 15) or the unmodified hygromycin B gene (lanes 17 to 20). Shown are hygromycin B constructs without introns (A and E), constructs containing the third intron of SC6 directly upstream of the start codon (B and F), constructs containing an artificial intron directly downstream of the stop codon (C and G), and constructs containing both the third intron of SC6 and the artificial intron (D and H). The mRNA was hybridized with a ³²P-labeled hygromycin B probe (A to D) or a ³²P-labeled ribosomal probe (E to H). The software used was Corel PhotoPaint 8.0 and CorelDRAW 8.0.