Ultrastructure of oocyte maturation, fertilization, and early embryo development in vitro in the Siberian tiger (Panthera tigris altaica)

• Published in: Molecular reproduction and development Vol. 63; no. 1; pp. 79 - 88
• Main Authors: GjØrret, J.O., Crichton, E.G., Loskutoff, N.M., Armstrong, D.L., Hyttel, P.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.09.2002; Wiley-Liss
• Subjects: Animals; assisted reproduction; Biological and medical sciences; Carnivora - embryology; Carnivora - physiology; Cell Nucleus - ultrastructure; Cleavage Stage, Ovum - cytology; embryo; Embryonic and Fetal Development; Female; Fertilization in Vitro - methods; Fertilization in Vitro - veterinary; Follicle Stimulating Hormone - pharmacology; Fundamental and applied biological sciences. Psychology; Luteinizing Hormone - pharmacology; Male; Mammalian female genital system; Meiosis; Morphology. Physiology; oocyte; Oocytes - cytology; Oogenesis - physiology; Organ Culture Techniques; Ovulation Induction - methods; Ovulation Induction - veterinary; Species Specificity; Swine - physiology; ultrastructure; Vertebrates: reproduction; wild cats; Fissipedia; Embryonic development; Carnivora; Embryo; Panthera tigris; Assisted procreation; Germinal cell; Fecundation; Vertebrata; Mammalia; Ultrastructure; Oocyte; Oocyte maturation
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.10133

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. Mol. Reprod. Dev. 63: 79–88, 2002. © 2002 Wiley‐Liss, Inc.