Fig. 1.

The MAR2xT7 transposon is TraSH-compatible. (A) Schematic of MAR2xT7 showing the gentamicin resistance cassette, two outwardly directed T7 promoter sites at both ends of the tranposon, and short, 28-bp inverted repeats. The top strand of MAR2xT7 as it is pictured represents Strand A, and the bottom strand represents Strand B. Primers that anneal to Strand B were used for sequencing and identification of mutants. (B) T7 polymerase-generated RNA created from five different MAR2xT7 mutants. Genomic DNA from each mutant was HinP1-digested, and Y-linkers were ligated to the ends as described in ref. 25. PCR-amplified DNA products were used as template for T7 RNA polymerase. The average size of the RNA products is ≈500 bp.