Influence of the Sperm Velocity on Fertilization Capacity in the Oscillatory Model of Mouse Zona Pellucida

Abstract

Considering the fertilization process as an oscillatory phenomenon, based on mechanotransduction theory of sperm–oocyte interaction, influence of sperm velocity and their specific arrangement on outer surface of oocyte- Zona pellucida (ZP) relative to the oscillatory behavior of ZP was studied using discrete continuum oscillatory spherical net model of mouse ZP. For the calculated favorable impact angles of spermatozoa by using generalized Lissajous curves, a parametric frequency analysis of oscillatory behavior of the knot molecules in the mouse ZP spherical net model is conducted. In order to mimic successful fertilization in physiological conditions in this numerical experiment, velocities of the progressive and hyperactivated spermatozoa were used. The resultant trajectories of knot molecules in mouse ZP (mZP) spherical net model, in the form of generalized Lissajous curves, are presented. Influences of the sperm velocity and its arrangement on the resultant trajectory of the corresponding knot molecules are discussed. Component displacements in the meridian and circular directions of the knot molecules of ZP are in the form of multi-frequency oscillations. Symmetrical arrangements of spermatozoa having effective velocities are more favorable for achieving a favorable oscillatory multi-frequency state of mZP for a successful fertilization. Determining the optimal parameters of spermatozoa impact that will induce a ZP favorable oscillatory state opens the possibilities for more complete explanation of the fertilization process.