FIG. 2.

Northern blot analysis of ectABC-ask operon and ectR1 gene mRNAs. Total RNA was prepared either from M. alcaliphilum 20Z cells grown with 1% NaCl (lanes 1) or 6% NaCl (lanes 3) or with cells exposed for 1 h to an osmotic upshift from 1% NaCl to a final salt concentration of 6% NaCl (lanes 2). Increasing amounts of total RNA were resolved on a denaturing agarose gel, blotted onto a Hybond-N⁺ membrane, and hybridized with [α³²P]dATP-labeled ask (A) or ectR1 (B) gene-specific probes. RNA ladders are indicated by arrows. rRNA (lower panels) was detected by ethidium bromide staining.