FIG. 3.

RT-PCR analysis of constitutively produced genes. RT-PCR was performed using DNase-treated total RNA from B. abortus transformed with pMC22Tac. Transcription was done in the presence (lanes 2, 4, 6, and 8) or absence (lanes 3, 5, 7, and 9) of reverse transcriptase and IF-1 primers (lanes 4 and 5), hypothetical protein primers (lane 6 and 7), or ohr primers (lanes 8, 9). GFP primers (lanes 2 and 3) were included as a positive control. Gene Ruler 50bp DNA Ladder was used as the molecular mass standard (lane 1).