Figure 4.

Southern hybridization profiles of DNA from M. genitalium strains. G37, wild-type; JB20, mg218 mutant. StyI, SpeI, and SpeI+StyI represent the restriction enzymes used to cut genomic DNA. DNA fragments were resolved in 0.8% agarose gel, Southern transferred to nitrocellulose membrane, and probed with the following: a 2-kb mg218 gene fragment (A; probe I); or a 2.5-kb gentamycin gene fragment (B; probe II). There was no positive signal with 3.9-kb pCR2 plasmid DNA (probe III) with JB20 DNA. Arrows indicate the hybridization signals due to similar size fragments of 3.2 kb and 3.3 kb. The sizes of the DNA bands are indicated in kilobases (kb).