Successful IVF Breakthrough Could Save Northern White Rhino

In a major breakthrough, the first successful southern white rhino in vitro fertilization has been carried out by scientists. It could mean hope in the quest to save the northern white rhino, whose last remaining members — cousins of the southern rhino — are both female.

Neither of the two northern white rhinos, Najin and Fatu, are able to carry a pregnancy to term, AFP reported. They live under around-the-clock protection from poachers at the Ol Pejeta Conservancy in Kenya.

Since there are no remaining male northern white rhinos, the species is functionally extinct. Scientists from the BioRescue consortium have been trying to implant a lab-grown embryo from a northern white rhino into a southern white rhino surrogate.

While the recent IVF pregnancy was successful — after 13 attempts — it ended when the surrogate, bull and fetus were all killed by an unrelated bacterial infection in their enclosure, reported AFP and BBC News.

“We achieved something that was not believed to be possible,” said leader of the project Thomas Hildebrandt at a Berlin press conference, as AFP reported.

The pregnancy period is 16 months, and while the fetus was just 70 days old, the scientists said they believed it could have lived to term.

They will now try to replicate their success with embryos from other eggs harvested from Najin and Fatu, coupled with sperm preserved from two male northern white rhinos who died long ago.

Cesare Galli from Avantea, the lab in Italy where the eggs were in vitro fertilized, said the quality of the remaining northern white rhino sperm is “very poor.”

The process of placing the embryo — which takes a little under an hour — is carried out while the surrogate is under anesthesia, reported AFP.

“The sperm injection, the fertilisation, the liquid nitrogen, the thawing – this was never done before for rhinos. All of it could have failed,” Hildebrandt told The Guardian.

Sundan, the last male northern white rhino, died at Ol Pejeta in 2018.

Hildebrandt said the team hopes to “produce northern white rhino calves in the next two to two-and-a-half years,” AFP reported.

BioRescue collected eggs from Najin and Fatu from 2019 to 2021, when they were retired from the breeding program. According to Susanne Holtze, a scientist with Germany’s Leibniz Institute for Zoo and Wildlife Research, the team has preserved 30 frozen, fertilized eggs.

“To achieve the first successful embryo transfer in a rhino is a huge step,” Holtze said, as reported by BBC News. “But now I think with this achievement, we are very confident that we will be able to create northern white rhinos in the same manner and that we will be able to save the species.”