Figure 1.

Decline in Preimplantation Developmental Competence during Postovulatory Aging and Rescue after Genome Transfer at MII

(A) Strategy for oocyte retrieval and the timing of in vitro culture and oocyte activation.

(B) Genome exchange between 5-hr and 20-hr incubated oocytes. The genome of 5-hr incubated oocytes is transferred into enucleated, 20-hr incubated oocytes (5G20C). After manipulation, they are artificially activated and observed for preimplantation development. A reciprocal exchange is also conducted.

(C) Preimplantation development of activated oocytes. Arrowheads indicate fragmentation.

(D) Genome exchange rescues preimplantation development of 20-hr incubated oocytes. The number of oocytes and the number of experiments (in parentheses) is indicated above each column. The error bars show mean ± SEM. ^∗p < 0.05, ^∗∗∗∗p < 0.0001; ns, not significant.

(E) Cell numbers in blastocyst from genome exchanged oocytes. The total number of blastocysts and the number of experiments (in parentheses) is indicated above each column. The error bars show mean ± SEM. ^∗p < 0.05, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001; ns, not significant.

(F–H) Oct4 immunostaining at blastocyst stage (F), ESC derivation (G), and karyotype of ESCs (H). Scale bars represent 20 μm.