FIG. 6.

Check of the FdBk mutant for WT copies of rcaE. (A) Autoradiogram of a Southern blot of genomic WT or FdBk DNA cut with BsaW1 and hybridized with an rcaE probe. The DNA insertion in rcaE in the FdBk mutant results in decreased mobility that is distinguishable from the mobility of the same region in WT. (B) PCR amplification and agarose gel electrophoresis were used to examine the size of the rcaE region in the genome of the WT and the FdBk mutant.