The University of Pretoria (UP) is working with international partners to perform in vitro fertilisation (IVF) to support dwindling rhinoceros populations.
The In Vitro Fertility Laboratory, which is part of UP’s Department of Production Animal Studies in the Faculty of Veterinary Science, is a major role player in this effort.
Professor Leith Meyer, Director of the Centre for Veterinary Wildlife Studies, said the focus of this laboratory is to develop artificial reproduction techniques that can be used to help with the conservation of threatened and endangered rhino species, and to help with the breeding of domesticated species where artificial methods are needed.
Rhino oocytes (ovaries and/or eggs).
One of the main areas of research being conducted in the lab is related to finding the best way to preserve and use harvested eggs and sperm from white rhino to ensure that viable embryos can be produced using IVF techniques.
“We would like to develop robust and repeatable methods and techniques that can be used to do artificial reproduction to bolster populations of threatened and endangered species or help domesticated animals reproduce more effectively,” Prof Meyer said. “These artificial reproduction technologies will also be used to help advance the genetic potential and diversity of certain species that require it.”
The International Rhino Reproduction Collaborative (IRRC) was established as a result of a joint initiative between UP and the San Diego Zoo Global, a non-profit organisation committed to saving species around the world, to unite experts in animal care and conservation science. Earlier this year, a team from San Diego Zoo Global and other members of the IRRC – which included veterinary scientists from UP, Embryo Plus, SANParks, the Institute of Rhino Cryogenetics, Geolife and Buffalo Dream Ranch – visited the IVF Laboratory. These experts shared scientific expertise about rhino physiology and artificial reproduction technologies to investigate and promote methods to optimise rhino gamete (eggs and sperm) retrieval.
“Artificial reproduction attempts in rhinos involve the harvesting of sperm samples from rhino bulls, and the successful freezing and storage of the samples in straws or vials in liquid nitrogen for future use,” explains Mario Smuts, veterinary technologist at the Department of Production Animal Studies. “Ovaries and/or eggs (oocytes) are also harvested from either rhino cows that are anaesthetised or from post-mortem material collected from rhinos that either died from natural causes or were poached. We are developing protocols to optimally transport ovaries and/or eggs from remote locations to the laboratories in a timely manner so that the eggs are still alive (viable) for fertilisation.
“Eggs that are successfully fertilised are then grown in incubators to form embryos (called blastocysts) that are stored in liquid nitrogen for future use. Each step in the in vitro fertilisation process is meticulously researched and tweaked for optimising oocyte survival, successful fertilisation, embryo growth and safe storage of embryos for later transfer to surrogate rhino cows.”
“Further research on how to best preserve and store these embryos will be done, and then we will do research on how to implant these embryos in surrogate rhino mothers to produce rhino calves,” adds Prof Meyer. “The ultimate research goal is to develop these techniques so that they can be used on stored genetic material to hopefully bring back the northern white rhino from the brink of extinction, though this research will also be used to help with the conservation of all rhino species. What we learn from this work should also help us to develop similar techniques for other endangered and domesticated animal species.”