FIG. 1.

Effect of cold shock on the levels of mRNAs. Total RNA was extracted by the hot phenol method as described in the text, and Northern blot analysis was carried out with deoxyoligonucleotides corresponding to cspA, malT, dps, mopB, rbsD, and fecA. Lanes 1 and 2 in each case except fecA represent mRNAs isolated from control (37°C) and cold-shocked (1 h) wild-type cells, respectively. In the case of fecA, lanes 1 and 2 represent mRNAs isolated from cold-shocked (1 h) wild-type and quadruple-deletion cells, respectively. The positions of the transcripts were determined using as reference ribosomal RNAs. Bands corresponding to 23S and 16S rRNAs were visualized by ethidium bromide staining of the gel.