Location of a transduced Salmonella H2 (phase-2 flagellin gene) region in Escherichia coli K-12

Abstract

The location of the Salmonella phase-2 flagellin gene and its associated regulatory elements, vh2⁺ H2 rh1⁺ and vh2 H2 rh1⁺, transduced into Escherichia coli K-12 was determined by interrupted matings to be around 55min on the linkage map. In P1 transduction with vh2 H2 nalB^r as donor, tyrA⁺ or pheA⁺ was cotransduced with vh2 H2 at frequencies of 3-6% but was not with nalB^r, suggesting that the integrated H2 region interferes with cotransduction of pheA and nalB which are known as cotransducible, and also its likely location at the nalB side of pheA. On the other hand, the vh2⁺ H2 region was not cotransduced with any markers tested and not transduced at all even when used as selective marker. This was discussed with relation to the constitution of the transducing fragment involving vh2⁺ H2. The delayed expression of H2 in transductants selected for auxotrophic markers was also discussed.