Table 1. Development of embryos derived from fully-grown, growing, and rescued oocytes.

Group	No. of embryos cultured	Blastocysts (%)	Total cell number in blastocysts
Control	100	27 (27.0 ± 5.5) a	50.4 ± 5.0 a
GR	100	0 c	--
GVTR	100	3 (3.0 ± 1.9) bc	23.3 ± 6.9 b
CFR	100	12 (12.0 ± 4.3) b	36.3 ± 4.8 ab

Control: oocytes collected from fully-grown follicles (2–6 mm in diameter) were fertilized and then cultured in vitro. GR: growing oocytes collected from early antral follicles (smaller than 1 mm in diameter) were fertilized and then cultured in vitro. GVTR: growing oocytes, rescued by transferring germinal vesicles (GV) into enucleated cytoplasts of fully-grown oocytes, were fertilized and then cultured in vitro. CFR: growing oocytes, rescued by fusion with enucleated cytoplasts of fully-grown oocytes, were fertilized and then cultured in vitro. Four trials were performed. Different letters denote significant differences in the same column (P < 0.05).