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Vertebrate reproductive science and technology
RESEARCH ARTICLE

Oocyte cryopreservation: oocyte assessment and strategies for improving survival

Sergio Ledda A B D , Luisa Bogliolo B , Sara Succu A , Federica Ariu B , Daniela Bebbere A , Giovanni Giuseppe Leoni C and Salvatore Naitana A
+ Author Affiliations
- Author Affiliations

A Department of Animal Biology, Veterinary Faculty, University of Sassari, 07100 Sassari, Italy.

B Institute of Animal Pathology, Pathological Anatomy and Obstetric and Surgery Clinics, Veterinary Faculty, University of Sassari, 07100 Sassari, Italy.

C Department of Physiological, Biochemical and Cellular Sciences, Veterinary Faculty, University of Sassari, 07100 Sassari, Italy.

D Corresponding author. Email: giodi@uniss.it

Reproduction, Fertility and Development 19(1) 13-23 https://doi.org/10.1071/RD06126
Published: 12 December 2006

Abstract

Despite significant progress in cryopreservation of mammalian oocytes and embryos, many of the molecular and biochemical events that underlie this technology are poorly understood. In recent years, researchers have focused on obtaining viable oocytes that are developmentally competent. Even under the most favourable conditions, experimental approaches have achieved only limited success compared with fresh oocytes used in routine in vitro embryo production. Chilling injuries and toxic effects of the cryoprotectants are the major adverse consequences following cryoprocedures. To overcome these problems, different strategies have been developed for improving cryopreservation results. These strategies include reducing container volumes, increasing the thermal gradient, changing the cell surface/volume ratio, enhancing cryotolerance by supplementation with various additives or modifying the lipid composition of the oocyte membrane. In order to develop new strategies for reducing the various forms of stress associated with oocyte cryopreservation, it is fundamental to gain a better understanding of the major changes responsible for poor post-thaw survival. With this knowledge, we hope that oocyte cryostorage will become a fully reliable reproductive technique in the near future.


Acknowledgments

Work from the authors’ laboratories was supported by FIRB 2001 Project by the Italian Minister of Research and University (RBNE01HPMX_003). The authors thank Paola Melis for assistance during the preparation of the manuscript.


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