Researchers at San Diego Zoo Global successfully recovered eggs from a rhinoceros last week in the ambitious effort to genetically recover the nearly extinct northern white rhino subspecies.
Working with Dr. Morne de la Rey of Embryo Plus South Africa, the team performed an ovum pick-up procedure on Nikita, a 9-year-old female southern white rhinoceros at the Safari Park.
The procedure is a non-surgical method of collecting eggs from a live animal modeled on a common method used on cows and horses. Throughout the procedure, Nikita was anesthetized and carefully monitored by a team of more than 30 specialists.
“We are grateful to collaborate with Dr. Morne de la Ray and his team on this important step in our efforts to save the northern white rhino from the brink of extinction,” said Barbara Durrant, director of reproductive sciences at San Diego Zoo Global. “Having viable, fresh eggs is very important to our work. Before OPU, we have only been able to collect eggs after an older animal dies. Older eggs are not very viable; the best eggs come from a living animal.”
“Now, our next step is to learn how to mature these eggs in culture, and how to fertilize them and grow them to the stage needed for embryo transfer,” she said.
Ultimately, scientists hope to use frozen cells preserved from 12 northern white rhinos to create new stem cells that can develop into sperm and eggs. Fertilized embryos would then be transferred to female southern white rhinos as surrogate mothers.
There are many challenges ahead, but researchers say they are optimistic that a northern white rhino calf could be born from these processes within 10 to 15 years. This work also may be applied to other rhino species, including critically endangered Sumatran and Javan rhinos.