title: Selection of pre- versus postpubertal pig oocytes for parthenogenetic activation and somatic cell nuclear transfer.
abstract: Pig oocytes have been used increasingly for in vitro production techniques in recent years. The slaughterhouse-derived oocytes that are often used are mostly of prepubertal origin. The aims of the present study were to compare the developmental competence between pre- and postpubertal pig oocytes, and to develop a simple and practical method for the selection of prepubertal pig oocytes for parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) based on oocyte morphology after IVM and oocyte inside zona pellucida (ZP) diameter ('small' ≤110µm; 'medium' >110µm; 'large' ≥120µm). Meiotic competence and blastocyst rates after PA and SCNT of prepubertal oocytes increased with oocyte size, with the large prepubertal oocytes reaching a level similar to postpubertal oocytes after SCNT. Blastocyst cell number was not related to oocyte inside ZP diameter and oocyte donor to the same extent as blastocyst rate. Very low blastocyst rates were obtained after PA of morphologically bad pre- and postpubertal oocytes. In conclusion, measurement of inside ZP diameter combined with morphological selection is useful to remove incompetent oocytes. Further studies are needed to clarify the relative importance of cytoplasmic volume and stage in oocyte growth phase.
authors.affiliation: Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: H S
authors.initials: HS
authors.lastname: Pedersen
authors.affiliation: Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Purup
authors.affiliation: Department of Molecular Biology and Genetics, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Løvendahl
authors.affiliation: Department of Veterinary Clinical and Animal Science, University of Copenhagen, DK-1870 Frederiksberg C, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Holm
authors.affiliation: Department of Veterinary Clinical and Animal Science, University of Copenhagen, DK-1870 Frederiksberg C, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Hyttel
authors.affiliation: Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Callesen
mesh_terms: D000367:Age Factors; D000818:Animals; D005260:Female; D008540:Meiosis / Q000502:physiology*; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000502:physiology*; D010312:Parthenogenesis / Q000502:physiology*; D013552:Swine; D015044:Zona Pellucida / Q000502:physiology