TABLE 2.

MPEV exhibits a mosaic expression pattern in ES cells

ES cell line and clone	Cloning efficiency (%) (% LacZ+ colonies)a		Neor colonies/ total colonies	LacZ+ colonies/ total colonies
	Without G418	With G418		Without G418	With G418
CCE	33.0 (0)	0.0 (0)	NAb	NA	NA
CCE-MPEVlacZneoR
6	18.2 (5.2)	6.5 (2.2)	0.36	0.35	0.36
9	27.3 (2.4)	5.1 (0.6)	0.19	0.09	0.12
13	30.6 (8.5)	14.6 (3.9)	0.48	0.28	0.27

^aCells were plated on inactivated feeder cells in either the absence or presence of G418. Results are averages from two independent experiments. 

^bNA, not applicable.