TABLE 2.

Frequency of recombination of S. meliloti megaplasmid deletions into wild-type strains carrying the empty plasmid vector pTH1931 or pTH1931 containing TA genes^a

^aThe diagram above the table illustrates the two homologous recombination events (dashed lines) that occur in transduction of deletion ΔCDET::Gm^r Nm^r from a donor strain into a wild-type recipient. The structure of the resulting Gm^r Nm^r transductant (recombinant) is shown. Similarly, the Gm^r Nm^r-marked ΔA257, ΔA131, ΔA132, and ΔB139 deletions (Fig. 2 and 3) were transduced using phage ΦM12 into RmP110 wild-type (WT) recipient strains carrying the empty Sp^r plasmid vector pTH1931 or pTH1931 carrying the TA gene regions as indicated.

^bNumbers of transductant colonies per plate as well as transductional frequency per recipient for each transduction are indicated. Results are representative of three independent experiments.