Oocyte quality determines bovine embryo development after fertilisation with hydrogen peroxide-stressed spermatozoa

Reprod Fertil Dev. 2012;24(4):608-18. doi: 10.1071/RD11237.

Abstract

Exposure of gametes to specific stressors at sublethal levels can enhance the gametes' subsequent performance in processes such as cryopreservation. In the present study, bull spermatozoa were subjected to H₂O₂ for 4 h at 100-, 200- and 500-μM levels; computer-assisted sperm analysis (CASA) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay were used for evaluation of subsequent sperm motility and DNA integrity, respectively. Exposure of spermatozoa to H₂O₂ did not affect sperm motility but DNA integrity was negatively affected by 500 μM H₂O₂ compared with mock-exposed spermatozoa, whereas both motility and DNA integrity were affected compared with untreated spermatozoa. Nevertheless, insemination of oocytes with spermatozoa exposed to 200 μM H₂O₂ increased fertilisation, cleavage and blastocyst rates (P < 0.05). Furthermore, the higher blastocyst yield after fertilisation of oocytes with spermatozoa exposed to 200 μM H₂O₂ was related to oocyte diameter, with large-medium oocytes yielding higher blastocyst rates, while small-diameter oocytes consistently failed to develop into blastocysts. In conclusion, the results indicate that exposure of spermatozoa to 200 μM H₂O₂ before sperm-oocyte interaction may enhance in vitro embryo production in cattle. However, this increased embryo production is largely dependent on the intrinsic quality of the oocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Blastocyst / cytology
  • Blastocyst / drug effects
  • Blastocyst / physiology
  • Cattle / physiology*
  • Cell Size
  • DNA Fragmentation / drug effects
  • Ectogenesis*
  • Female
  • Fertilization in Vitro / veterinary
  • Hydrogen Peroxide / adverse effects
  • Hydrogen Peroxide / pharmacology*
  • Image Processing, Computer-Assisted
  • Male
  • Oocytes / cytology
  • Oocytes / physiology*
  • Oogenesis*
  • Osmolar Concentration
  • Oxidants / adverse effects
  • Oxidants / pharmacology
  • Oxidative Stress / drug effects*
  • Sperm Motility / drug effects
  • Sperm-Ovum Interactions / drug effects
  • Spermatozoa / drug effects*
  • Spermatozoa / physiology

Substances

  • Oxidants
  • Hydrogen Peroxide