Figure 3.

Effect of the hairpin secondary structure in noncoding region of M segment on the stability and homogeneity of the virus. Photograph of plaques from bacteriophage isolates where lacH is inserted in the noncoding region of the M segment and bordered with poly-G and poly-C homopolymer arms (B) or lacking one of the arms (A). Plaques lacking the one of the homopolymer arms are stable and form uniform blue plaques on LB X-Gal substrate (A). The lacH gene bordered by homopolymer arms is unstable, producing the white and blue mixed plaque population (B). Reproduced from Onodera et al. (1993).