title: The effects of blastomere biopsy and oxygen tension on bovine embryo development, rate of apoptosis and interferon-tau secretion.
abstract: A series of experiments was performed to examine the effects of blastomere biopsies on subsequent development of IVF-derived bovine embryos. The first experiment was designed to assess the optimal time for blastomere removal. One blastomere was removed either 48 or 72 h after IVF. Biopsy at 48 h resulted in 17.2% of embryos proceeding to the blastocyst stage, which was lower than when biopsies were performed at 72 h (37.5%, p < 0.05). In the second experiment, embryos were cultured either under atmospheric or 5% O(2) following blastomere removal. Biopsies had no effect on rate of blastocyst formation with 36% of controls and 33.7% of biopsied embryos proceeding to that stage. However, culture under 5% O(2) significantly increased the number of blastocysts from 29.9% to 40.3% (p < 0.05). This effect was significant in both biopsied and control embryos. In the final experiment, biopsied embryos were again cultured under different oxygen tension. Blastocysts were collected and cultured individually for 48 h in medium droplets in their respective O(2) concentration after which time the medium was assayed for concentration of interferon-tau (IFN-tau). Reduced O(2) concentration again significantly increased blastocyst formation from 24.9% to 41.9% (p < 0.05). IFN-tau secretion was not affected by biopsies, but culture under atmospheric O(2) resulted in significantly increased IFN-tau concentration in medium droplets (12274.0 +/- 2825.9 pM vs 5046.5 +/- 2562.2 pM; p < 0.05).
authors.affiliation: Unit of Reproductive Biology, Division of Veterinary Medicine, Tulane National Primate Research Center, Covington, LA 70433, USA. mkubisch@tulane.edu
authors.forename: H M
authors.initials: HM
authors.lastname: Kubisch
authors.forename: K M
authors.initials: KM
authors.lastname: Johnson
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001706:Biopsy / Q000662:veterinary; D001755:Blastocyst / Q000187:drug effects / Q000502:physiology*; D001757:Blastomeres / Q000473:pathology / Q000502:physiology; D002417:Cattle / Q000196:embryology* / Q000235:genetics; D002452:Cell Count / Q000662:veterinary; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D007370:Interferon Type I / Q000378:metabolism*; D008297:Male; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology*; D011257:Pregnancy Proteins / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007370:Interferon Type I; D011257:Pregnancy Proteins; C020947:interferon tau; D010100:Oxygen