Attempted in Vitro Maturation and Fertilization of Postmortem Sumatran Rhinoceros (Dicerorhinus sumatrensis) Oocytes

• Published in: Journal of zoo and wildlife medicine Vol. 42; no. 4; pp. 723 - 726
• Main Authors: Stoops, Monica A, Bateman, Helen L, Campbell, Mark K, Roth, Terri L
• Format: Journal Article
• Language: English
• Published: United States American Association of Zoo Veterinarians 01-12-2011
• Subjects: Animals; BRIEF COMMUNICATIONS; Cell Culture Techniques - veterinary; Cryopreservation; Dicerorhinus sumatrensis; Endangered Species; Female; Fertilization; Fertilization in Vitro - veterinary; Follicles; In vitro fertilization; in vitro maturation; Metaphase; oocyte; Oocytes; Oocytes - cytology; Oocytes - physiology; Ovaries; Perissodactyla; Spermatozoa; Sumatran rhinoceros; Zona pellucida; Zoos
• ISSN: 1042-7260; 1937-2825
• DOI: 10.1638/2010-0186.1

A study was conducted opportunistically to evaluate the potential of rescuing immature oocytes from the ovaries of the Sumatran rhinoceros postmortem. Recovered oocytes (n = 30) were placed in maturation culture for 36 hr and inseminated with frozen-thawed homologous spermatozoa. After culture, evaluation of nuclear maturation status revealed that a large number of oocytes were degenerated (n = 21), but nine oocytes were assessed at the germinal vesicle (n = 3), metaphase I (n = 3), and metaphase II (n = 3) stages. Frozen-thawed Sumatran rhinoceros spermatozoa were capable of binding to the zona pellucida of in vitro matured oocytes, but no fertilization or cleavage resulted. In conclusion, relatively large numbers of oocytes can be obtained by ovarian follicular aspiration postmortem in the Sumatran rhinoceros, and some of these oocytes are capable of achieving nuclear maturation in vitro. However, additional studies are required to improve maturation success and achieve fertilization in culture.