FIG. 4.

Expression of relA in wild-type cells and nla18 mutant cells. QPCR was used to examine developmental expression of relA in the wild-type and nla18 mutant backgrounds as described in Materials and Methods. Expression of the relA gene was determined by the absolute method of quantification, and the expression levels were normalized to levels in wild-type cells at time zero (vegetative growth). Expression of relA in wild-type strain DK1622 (black squares) and nla18 mutant strain AG318 (empty squares) was determined with primers relAfwd and relArev (Table 1). The values shown are means derived from four replicates. Error bars are standard deviations of the means.