BOR - Papers in Press, published online ahead of print
October 4, 2002.
Biol Reprod 2002, 10.1095/biolreprod.102.004770
Biology of Reproduction 67, 1790-1795 (2002)
DOI: 10.1095/biolreprod.102.004770
© 2002 Society for the Study of Reproduction, Inc.
Serial Pronuclear Transfer Increases the Developmental Potential of In Vitro-Matured Oocytes in Mouse Cloning1
Björn Heindryckx2,a,
Andreï Rybouchkina,
Josiane Van der Elsta, and
Marc Dhonta
a Infertility Center, Department of Obstetrics and Gynaecology, Ghent University Hospital, 9000 Ghent, Belgium
In vitro-matured germinal vesicle oocytes are an interesting source of cytoplast recipients in both animal and human nuclear transfer (NT) experiments. We investigated two technical aspects that might improve the developmental potential of nuclear transfer mouse embryos constructed from in vitro-matured germinal vesicle oocytes. In a first step, the effect of two maturation media on the embryonic development of NT embryos originating from in vitro-matured oocytes was compared. Supplementation of the oocyte maturation medium with serum and gonadotrophins improved the developmental rate of NT embryos constructed from in vitro-matured oocytes, but it was still inferior to that obtained with in vivo-matured metaphase II (MII) oocytes. Second, we investigated the effect of serial pronuclear transfer from NT zygotes originating from both in vitro- and in vivo-matured oocytes to in vivo-fertilized zygotic cytoplasts. Blastocyst quality was evaluated by counting nuclei from trophectoderm and inner cell mass cells using a differential staining. Sequential pronuclear transfer significantly improved the blastocyst formation rate of NT embryos originating from in vitro-matured oocytes up to the rate obtained with in vivo-matured MII oocytes. We conclude that the developmental potential of NT embryos constructed from in vitro-matured oocytes can be optimized by serial pronuclear transfer to in vivo-produced zygotic cytoplasts.
1 Supported by a research grant from the Bijzonder Onderzoeksfonds of the Ghent University, Belgium (grant BOF 01110301).
2 Correspondence: Björn Heindryckx, Infertility Center, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. FAX: 32 9 240 4972; bjorn.heindryckx{at}rug.ac.be
Copyright © 2002 by the Society for the Study of Reproduction.