Related Experiment Video
Updated: Aug 8, 2026
Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes
Published on: November 11, 2022
Electrical activation of mouse oocytes
P Collas1, J J Balise, G A Hofmann
1Department of Veterinary and Animal Sciences University of Massachusetts Amherst, Massachusetts 01003 USA.
Abstract:
Activation of the oocyte is the least efficient step in nuclear transplantation in the rabbit. We report the influence of age of oocytes, field strength, pulse duration and number, and shape of field on the rate of activation of mouse oocytes by electrical pulses. Regardless of oocyte age, activation rates were similar over a wide range of field strengths and pulse durations. Aged oocytes activated at a higher rate than recently ovulated oocytes (32 vs 3%), which lysed more frequently (13 vs 2%). Fragmentation rate was also higher among aged oocytes (42 vs 6%). The rate of activation increased with the number of pulses, from 9% with a single pulse, to 61% with six pulses. It also increased with the interval between pulses. Comparison of activation chamber geometries showed that the rate of activation was higher in a nonuniform field than in a uniform field and, for a particular field strength, varied from one electrode gap to another. These observations indicate that the rate of activation can be greatly increased by multiple electrical pulses. The activation rate also varied with consistent field strength in chambers with different electrode configurations.
Insights
Multiple electrical pulses significantly increase mouse oocyte activation rates for nuclear transplantation. Aged oocytes show higher activation but also increased lysis and fragmentation compared to younger ones.
Area of Science:
- Reproductive Biology
- Developmental Biology
- Cellular Biology
Background:
- Oocyte activation is a critical and often inefficient step in nuclear transplantation.
- Optimizing oocyte activation is essential for improving the efficiency of reproductive technologies.
Purpose of the Study:
- To investigate the impact of various electrical pulse parameters on mouse oocyte activation rates.
- To determine the influence of oocyte age and electrical field characteristics on activation efficiency.
Main Methods:
- Electrical pulses were applied to mouse oocytes with varying field strengths, pulse durations, numbers, and intervals.
- Different electrode configurations and field geometries (uniform vs. nonuniform) were tested.
- Oocyte activation, lysis, and fragmentation rates were quantified.
Main Results:
- Oocyte activation rates were largely independent of field strength and pulse duration across a wide range.
- Aged oocytes exhibited higher activation rates (32%) but also increased lysis (13%) and fragmentation (42%) compared to recently ovulated oocytes (3% activation, 2% lysis, 6% fragmentation).
- Activation rates increased significantly with the number of pulses (9% for one pulse to 61% for six pulses) and pulse interval.
- Nonuniform electrical fields and specific electrode configurations resulted in higher activation rates.
Conclusions:
- Multiple electrical pulses are highly effective in enhancing mouse oocyte activation for nuclear transplantation.
- Oocyte age influences activation efficiency and viability, with aged oocytes being more prone to damage.
- Optimizing electrical pulse parameters and chamber geometry can significantly improve success rates in oocyte activation procedures.
More Related Videos
05:43Capturing Cytoskeleton-Based Agitation of the Mouse Oocyte Nucleus Across Spatial Scales
Published on: January 12, 2024
07:24Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments
Published on: December 31, 2016