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Isolation and Characterization of Mouse Antral Oocytes Based on Nucleolar Chromatin Organization
07:16

Isolation and Characterization of Mouse Antral Oocytes Based on Nucleolar Chromatin Organization

Published on: January 7, 2016

How long do parthenogenetically activated mouse oocytes maintain the ability to accept sperm nuclei as a genetic

Hiroyuki Tateno1, Yujiroh Kamiguchi

  • 1Department of Biological Sciences, Asahikawa Medical College, Asahikawa 078-8510, Japan. htateno@asahikawa-med.ac.jp

Journal of Assisted Reproduction and Genetics
|April 23, 2005
PubMed
Abstract

Insights

Intracytoplasmic sperm injection (ICSI) into mouse oocytes within one hour of artificial activation resulted in normal embryo development. Delaying ICSI beyond one hour increased risks of abnormal male pronucleus formation and chromosome aberrations.

Area of Science:

  • Reproductive Biology
  • Developmental Biology
  • Genetics

Background:

  • Artificial oocyte activation is crucial for assisted reproductive technologies.
  • Understanding the timing of intracytoplasmic sperm injection (ICSI) post-activation is vital for embryo development.
  • Cytogenetic integrity is a primary concern in ICSI procedures.

Purpose of the Study:

  • To evaluate the cytogenetic risks associated with ICSI performed after artificial oocyte activation in a mouse model.
  • To determine the optimal time window for ICSI following parthenogenetic activation to ensure embryo viability.

Main Methods:

  • Mouse oocytes were artificially activated using strontium (Sr).
  • Intracytoplasmic sperm injection (ICSI) was performed at varying intervals after activation.
  • Male pronucleus formation and chromosomal constitution of resulting zygotes were analyzed.

Main Results:

  • Normal male pronucleus formation and no significant increase in chromosome aberrations were observed when ICSI was performed within 1 hour of activation.
  • Delayed ICSI (beyond 1 hour) led to reduced male pronucleus formation rates.
  • The incidence of chromosome aberrations increased with longer intervals between oocyte activation and ICSI.

Conclusions:

  • Performing ICSI within one hour of artificial oocyte activation in mice yields cytogenetically competent embryos.
  • This timing is critical for minimizing risks of developmental abnormalities in post-activation ICSI.
  • The findings provide essential guidance for optimizing ICSI protocols in assisted reproduction.

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