Many events in oocytes and embryos, such as polar body formation, nuclear migration, and mitotic cleavage, are dependent on normal distribution of actin filaments. Because the dynamics of the actin cyto-skeleton is affected by the environment, such as temperature, pH, and ion strength, the actin cytoskeleton organization of embryos produced in vitro may be different from those derived from in vivo. Recent studies in the hamster and rat indicate that distribution of actin filaments was affected by the composition of the culture medium, and the distribution of some organelles, such as mitochondria, was dependent upon normal microfilament distribution, which directly or indirectly affected cleavage of the embryos. buy ventolin inhalers
However, the relationship between actin cyto-skeleton distribution and embryo development in the pig is poorly understood. Moreover, systematic examination and comparison of morphology between in vitro-produced embryos and in vivo-derived embryos have not been reported. A detailed morphological examination of embryos at early stages may be helpful in investigating the reasons for failure of embryo development. In the present study, we evaluated the morphology of pig embryos produced in vivo and in vitro, with particular reference to relationship between actin filament distribution and embryo development.