TABLE 2.

Quantitation of the relative transcript levels of ABC transporter Atr genes^a

Drug	Relative transcript level
	AtrA	AtrB	AtrC	AtrD
None (control)	1.00	1.00	1.00	1.00
Camptothecin	0.09	ND	0.52	4.25
Imazalil	0.04	30.06	13.68	9.83
Itraconazole	0.05	39.05	5.45	23.31
Hygromycin	2.81	ND	62.77	279.04
4-NQO	14.21	4,760.57	2.30	3.94

^aQuantitation of the relative transcript levels of Atr genes from the A. nidulans wild-type strain grown in the presence of several unrelated drugs compared to the wild type grown in the absence of any drug. The measured quantity of each ABC transporter gene mRNA in each of the treated samples was normalized using the C_ts obtained for the tubC RNA amplifications run on the same plate. The relative levels of ABC transporter and tubulin transcripts were determined by a standard curve (i.e., C_ts plotted against logarithm of the DNA copy number). The results are averages of three repetitions. The values represent the number of times the genes are expressed compared to the wild-type control grown without any drug (set at 1.00). ND, not determined.