Cortical Actin Cytoskeleton in Human Oocytes: a Comparison with Mouse Oocytes

The arrangement of the cortical actin cytoskeleton was studied, using fluorescence microscopy, in human and mouse oocytes. The study was focused on the distribution of filamentous actin (Factin) in the cortex region because our previous experiments have shown that the actin cytoskeleton has a high sensitivity to mechanical deformation of the cell during micromanipulation treatment. We found several similarities in morphology between the human and the mouse actin cytoskeleton, namely, a fine meshwork composed of short, thin actin fibres organised in clusters of varying density, formation of protrusions on the cell surface, etc. The participation of actin structures in the processes of oocyte maturation, known to exist in non-mammalian organisms, was also demonstrated. The observations presented in this study are preliminary results of a detail investigation into the actin cytoskeleton response to micromanipulation treatment which is related to assisted reproduction.