TABLE 1.

Telomere abnormalities in TRF1-depleted human foreskin fibroblasts^a

Parameter	Value
	Control shRNA	TRF1 shRNA 1	TRF1 shRNA 2
No. of telomeres analyzed	1,048	1,136	1,084
No. (%) of samples with phenotype
Doublet and broken telomere signals	3 (0.29)	6 (0.53)	27 (2.49)
Loss of telomere signals	14 (1.34)	26 (2.29)	30 (2.77)
End-to-end fusion of telomeres	0 (0)	0 (0)	0 (0)

^aCells were treated with 0.125 μg/ml colcemid for 16 h, and the metaphase spreads were analyzed by telomere FISH.