Genetics. In the article “Evolution of rhizobia by acquisition of a 500-kb symbiosis island that integrates into a phe-tRNA gene” by John T. Sullivan and Clive W. Ronson, which appeared in number 9, April 28, 1998, of Proc. Natl. Acad. Sci. USA (95, pp. 5145–5149), the authors wish to note that, in their article, the quality of reproduction of Fig. 1 was below standard. In particular, many of the hybridizing bands appeared diffuse and the background was blotchy, making interpretation of the banding patterns difficult. The figure and its legend are reproduced below.

Figure 1.

Southern blot analysis demonstrating transfer of the symbiotic element to three species of nonsymbiotic mesorhizobia. Genomic DNA from the donor strain ICMP3153 and pairings of nonsymbiotic and symbiotic strains was digested with EcoRI and hybridized (A) with three random genomic HindIII fragments of ICMP3153 (18) and (B) with pRLnodAC containing M. loti nodAC genes (18).