Table 2.

Examination of ES cell nuclei after transfer into enucleated oocytes, 6 h after oocyte activation by Sr²⁺

ES cells*	No. of oocytes examined	No. (%) of incoming nuclei transformed to one or more pseudo-pronuclei (pp) with or without extrusion of a pseudo-second polar body (ppb)
		Not transformed	1pp and ppb	1pp	2pp	3pp
Small	23	0	0	1  (4.3)	18  (78.3)	4  (17.4)
Large	22	1  (4.5)	15  (68.2)	3  (13.6)	3  (13.6)	0

^*Reconstructed oocytes were activated in the presence (small cells) or absence (large cells) of cytochalasin B as described in Materials and Methods. Cell sizes are as for Table 1.