Aberrant spindle structures responsible for recurrent human metaphase I oocyte arrest with attempts to induce meiosis artificially

Your ADS Text

Skip Navigation

B. Heindryckx1,*, S. Lierman1, C.M. Combelles2, C.A. Cuvelier3, J. Gerris1 and P. De Sutter1

1Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium

2Biology Department, Middlebury College, Middlebury, VT, USA

3Department of Pathology, Ghent University Hospital, Ghent, Belgium *Correspondence address. Tel: +32-9-332-4748; Fax: +32-9-332-4972; E-mail: bjorn.heindryckx{at}ugent.beReceived September 7, 2010. Revision received November 22, 2010. Accepted December 20, 2010. BACKGROUND In some couples, not all retrieved oocytes mature, even after prolonged in vitro culture. The underlying mechanisms are not known, although ionophore treatment may alleviate metaphase I (MI) arrest in some mouse strains. We attempted to induce first polar body (PB) extrusion and fertilization using assisted oocyte activation (AOA) after ICSI in maturation-resistant human MI oocytes.

METHODS Four ICSI patients are described in this retrospective study. A pilot study tested the calcium ionophore ionomycin (10 µM) on donated MI oocytes from patients with a normal number of metaphase II (MII) oocytes. Subsequently, ionomycin was used to induce first PB extrusion in two patients showing maturation-resistant MI oocytes. AOA, by calcium injection and ionomycin exposure, was applied when mature oocytes were available. Oocytes were analysed by polarized microscopy and immunostaining.

RESULTS Ionomycin induced the first PB extrusion in MI oocytes from patients with a normal number of retrieved MII oocytes, while extended in vitro culture failed to achieve the MII stage. Similarly, ionomycin induced first PB extrusion in one of two patients with recurrent maturation-resistant MI oocytes. Use of ICSI combined with AOA on MII oocytes matured in vitro or in vivo resulted in failed or abnormal fertilization with no further embryo cleavage potential. Highly abnormal spindle and chromosome configurations were observed in MI maturation-resistant oocytes, in contrast to control MI oocytes.

CONCLUSIONS Ionophore induced first PB extrusion in MI oocytes from patients without maturation arrest but to a lower extent in maturation-resistant MI oocytes. Immunofluorescence staining and confocal analysis revealed, for the first time, highly abnormal spindle/chromosomal structures that may be responsible for this maturation arrest.

© The Author 2011. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com This ArticleHum. Reprod. (2011) 26 (4): 791-800. doi: 10.1093/humrep/deq400 First published online: January 17, 2011

Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.

View the original article here

Peliculas Online