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Author Spotlight: Understanding DNA Damage Response in Mammalian Oocytes and Preimplantation Embryos
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Author Spotlight: Understanding DNA Damage Response in Mammalian Oocytes and Preimplantation Embryos

Published on: June 23, 2023

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DNA damage repair is suppressed in porcine aged oocytes

Tao Lin1,2, Ling Sun1,2, Jae Eun Lee2

  • 1School of Life Sciences and Food Engineering, Hebei University of Engineering, Handan 056038, China.

Journal of Animal Science and Technology
|November 19, 2021
PubMed

Insights

Aging porcine oocytes accumulate DNA damage and show reduced DNA repair capacity. This is linked to decreased homologous recombination and nonhomologous end-joining pathway gene expression, impacting embryo quality.

Area of Science:

  • Reproductive Biology
  • Molecular Biology
  • Genetics

Background:

  • Oocyte aging is a significant factor affecting female fertility.
  • Understanding the molecular mechanisms underlying oocyte aging is crucial for reproductive health.

Purpose of the Study:

  • To investigate DNA damage and repair mechanisms in postovulatory aged porcine oocytes.
  • To elucidate the impact of aging on DNA repair pathways and subsequent oocyte quality.

Main Methods:

  • Assessed DNA damage via H2A.X expression.
  • Evaluated DNA repair capacity by measuring RAD51 expression.
  • Analyzed gene expression in homologous recombination (HR) and nonhomologous end-joining (NHEJ) pathways.
  • Quantified cell cycle checkpoint gene expression (CHEK1, CHEK2).
  • Measured H3K79me2 levels using immunofluorescence.
  • Assessed embryo quality by cell proliferation capacity.

Main Results:

  • Increased DNA damage response (H2A.X expression) in aged porcine oocytes.
  • Decreased DNA damage repair capacity (RAD51 expression) in aged oocytes.
  • Downregulation of HR and NHEJ pathway genes, suppressing DNA repair.
  • Upregulation of cell cycle checkpoint genes (CHEK1, CHEK2) in response to DNA damage.
  • Reduced H3K79me2 levels in aged oocytes.
  • Significantly reduced embryo quality in aged oocytes.

Conclusions:

  • Postovulatory aging in porcine oocytes leads to increased DNA damage.
  • DNA repair ability is suppressed in aged oocytes due to impaired HR and NHEJ pathways.
  • Oocyte aging negatively impacts embryo development and quality.
Keywords:
DNA damageDNA repairH3K79me2Oocyte agingPig

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