Figure 3.

Identification of sigma factor cDNAs obtained by SCOTS. cDNA probes normalized by three rounds of SCOTS obtained from broth cultures grown to an OD (A₆₀₀) of 0.15 (B) or 0.54 (C) or from infected macrophages 18 h (D) or 48 h (E) after phagocytosis were used in Southern hybridization assays with previously described (22) agarose gel-purified, PCR-amplified DNA fragments (A) containing sigA (160 bp), sigB (106 bp), sigC (85 bp), sigD (113 bp), sigE (115 bp), sigF (92 bp), sigG (91 bp), sigH (81 bp), or rpoB (418 bp). mig (150 bp) is an M. avium DNA fragment not present in H37Rv.