Table II.

Gene expression measured by qRT-PCR

	Hsp70_5
	CTRL		HS
	Endogenous	Transgene	Endogenous	Transgene
aRelative	1	0.63 ± 0.11	140 ± 23	200 ± 56
bNormalized	1	0.14 ± 0.02	140 ± 23	45 ± 12

		MT1_1_4		DHFR D10
	CTRL	Zn		Log phase	G1 block
		2 h	16 h	(CTRL)
cRelative	1	3.9 ± 0.14	51 ± 8.3	1	0.31 ± 0.046

^aExpression levels relative to endogenous HSPA1A expression level at control temperature—human specific primers were used for BAC transgene, a 100% rat/mouse conserved sequence (specific for the CHO endogenous HSPA1A copy) was used for the endogenous gene.

^bExpression levels normalized for copy number estimated by mean of qPCR data (Table I).

^cExpression levels relative to control.

qRT-PCR was performed on four independent experiments for the Hsp70_5 cell line and three independent experiments for the DHFR D10 and MT1_1_4 cell lines. The comparative 2^−ΔΔCt method was used for relative expression level measurements. The β-actin gene was used as the endogenous control to normalize RNA loading. Numbers shown are the mean ± SE. PCR primers are listed in Table S2.