Table 1. Determination of telomerase activity in U. maydis strains.

Cell type	Cell extract treatment*
	None	Heated	RNase
HEK293	1.599	0.145	0.219
521 strain	0.870	0.180	0.307
trt1-1	0.261	0.206	0.118
trt1-2	0.249	N.D.	N.D.
Plant	0.081	N.D.	N.D.
Tumor (520×521)	0.182	N.D.	N.D.

The average absorbance values yielded by the telomerase activity in cell extracts are numerically expressed and shown in the chart. The absorbance for each sample was calculated according to the manufacturer's instructions and is shown. Heat- (85°C) and RNase-treated samples were used as negative controls. Telomerase activity was measured under the same conditions in the positive controls and tested samples. Telomerase activity was measured only in the mutant trt1-1; telomerase-negative samples (either from mutants, tumors, or plants) were not treated with heat or RNase, and their activity was not determined (N.D.). All of the experiments were performed at least three times.

* Media of at least three repetitions.