Figure 2.

(A) Structural changes at the Mbb1 locus of the 222E mutant. (Top) Growth test on acetate (Tris-acetate-medium) and minimal medium (high-salt) of wild type (WT), 222E (Left) and the four progeny A, B, C, and D from one of the three tetrads analyzed from the cross between wild type and 222E (Center). 222E⁺ refers to the 222E mutant strain rescued with the genomic Mbb1 DNA (Right). (Bottom) Southern blot analysis of DNA of the wild type, 222E, the progeny A, B, C, and D, and 222E⁺. The DNAs were digested with PstI and hybridized with the labeled cDNA. Fragment sizes of the marker are indicated in kilobases. (B) Mbb1 transcript. RNA blot with ≈2 μg of polyadenylated RNA from wild type and 222E hybridized with the Mbb1 cDNA and an RbcS probe. Sizes are indicated in kilobases.