title: Ultrastructure of oocyte maturation, fertilization, and early embryo development in vitro in the Siberian tiger (Panthera tigris altaica).
abstract: The application of assisted reproduction techniques to wild cats has been stalled by a lack of basic knowledge of the reproductive biology in these species. In this study, the ultrastructure of Siberian tiger (Panthera tigris altaica) cumulus-oocyte-complexes (COCs), as well as in vitro produced (IVP) zygotes and embryos were investigated, to estimate the normality of the manipulated reproduction processes. Adult female tigers were subjected to a purified porcine pFSH/pLH stimulation treatment followed by oocyte aspiration. According to morphological appearance at the stereomicroscopical level, COCs were classified as mature, immature, or degenerated, and then allocated into the following groups: presumptively immature COCs, which were in vitro matured (IVM-group) before fixation; presumptively mature COCs, which were either fixed after retrieval (pre-IVF-group), following in vitro insemination (IVF-group) or following in vitro insemination and subsequent in vitro culture (IVC-group). All specimens were processed for light and transmission electron microscopy (TEM). Both the IVM- and pre-IVF-group included oocytes in meiotic stages ranging from prophase I to metaphase II, and some prophase I oocytes in the IVM-group were apparently in their growth phase. The IVF-group presented features of presumptive normal fertilization, but aberrations such as polynucleation were also noted. The IVC-group included cleavage stage embryos of which, however, many were polynucleated. In conclusion, the procedures used for stimulation, aspiration, and classification of COCs resulted in retrieval of a heterogeneous population of oocytes which, following IVF and IVC, displayed a high rate of developmental deviations.
authors.affiliation: Department of Anatomy and Physiology, The Royal Veterinary and Agricultural University, Frederiksberg C, Denmark. jog@kvl.dk
authors.forename: J O
authors.initials: JO
authors.lastname: Gjørret
authors.forename: E G
authors.initials: EG
authors.lastname: Crichton
authors.forename: N M
authors.initials: NM
authors.lastname: Loskutoff
authors.forename: D L
authors.initials: DL
authors.lastname: Armstrong
authors.forename: P
authors.initials: P
authors.lastname: Hyttel
mesh_terms: D000818:Animals; D002335:Carnivora / Q000196:embryology / Q000502:physiology*; D002467:Cell Nucleus / Q000648:ultrastructure; D002970:Cleavage Stage, Ovum / Q000166:cytology; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D008540:Meiosis; D009865:Oocytes / Q000166:cytology*; D009866:Oogenesis / Q000502:physiology*; D009924:Organ Culture Techniques; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary; D013045:Species Specificity; D013552:Swine / Q000502:physiology
chemical_list: D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone