Modeling and Verification of the Oocyte Enucleation Process Based on the Material Point Method

The precise modeling of the oocyte enucleation process is the key to optimizing the efficiency of nuclear transfer. The process of oocyte enucleation involves complex mechanical behaviors such as cell deformation, displacement, and internal material flow. In view of the limitations of the existing modeling methods for oocyte enucleation in terms of computational accuracy, this study proposes an oocyte enucleation simulation model based on the Material Point Method (MPM). Firstly, we constructed a micrometer-scale oocyte enucleation model by introducing the intracellular pressure effect and the friction factor. This model enhanced the traditional MPM model's capability in characterizing cellular mechanical properties. Secondly, model parameters were calibrated and validated through comparative analysis of internal strain data which were obtained from both physical and simulated enucleation processes. Finally, this enucleation simulation model was used to predict changes in the position of the cytoplasm interface within the enucleation micropipette under different enucleation pressure trajectories. Experimental results showed that the model can effectively predict the dynamic changes in the cytoplasmic interface under different enucleation pressure trajectories, with the coefficient of determination (R²) between predicted and real data reaching 0.93. These results validate the effectiveness of this enucleation model, providing a reliable numerical analysis tool for oocyte enucleation procedures.