Equine embryos at the compacted morula and blastocyst stage can be obtained by intracytoplasmic sperm injection (ICSI) of in vitro matured oocytes with frozen-thawed spermatozoa from semen of different fertilities

摘要

The technique of oocyte maturation has been recently investigated by several authors in the equine species [1-4]. Following maturation intracytoplasmic sperm injection (ICSI) has been successfully used to obtain high rate of pronuclei formation and cleavage. It has been shown that embryos produced by in vitro maturation and ICSI can be developed in the oviduct of sheep temporary recipients giving rise to compacted morulae and blastocysts capable of establishing pregnancies [5]. In all studies fertile stallions were used for ICSI except one study [6] in which, however, in vivo and not in vitro oocytes were injected. Since in humans ICSI is extensively used especially for those patients that produce ejaculates of poor quality, the aim of this work has been to investigate the efficiency of the ICSI procedure by using in vitro matured oocytes and frozen-thawed semen of stallions of high and low fertility and/or motility after thawing. A second objective has been to investigate whether ICSI of in vitro matured oocytes could be used as an in vitro test to predict the in vivo fertility of frozen-thawed stallion semen.