FIG. 3.

(A) PCR analysis of P. multocida mutants. Chromosomal DNA from hgbA (lane 3) and PM0298 (lane 6) mutants were subjected to PCR analysis with the Aad oligonucleotide (Table 2) as the upper primer and the HgbArp and HgbAintrp oligonucleotides (Fig. 1A), respectively, as the lower primers. PCRs performed with chromosomal DNA from the wild-type strain (lanes 2 and 5) and these primer pairs and PCRs performed with preparations lacking DNA template (lanes 4 and 7) were the negative controls. Lane 1 contained HindIII-digested λ DNA as the molecular size marker. (B) RT-PCR study of the P. multocida hgbA mutant. RNA from hgbA (lane 3) and wild-type (lane 4) cells were subjected to RT-PCR analysis with the RTHgbAup and RTHgbArp oligonucleotides (Table 2). The control for RNA integrity was an RT-PCR amplification performed with RNA from hgbA cells and oligonucleotides RecAup and RecAdw belonging to the internal sequence of the P. multocida recA gene (lane 2). PCR performed with chromosomal DNA from the wild-type strain and oligonucleotides RTHgbAup and RTHgbArp (lane 5) and RT-PCR amplification of preparations containing the same primers but lacking both DNA and RNA templates (lane 6) were the product size and negative controls, respectively. Lane 1 contained BstEII-digested λ DNA as the molecular size marker.