NAIROBI – Scientists working to save the northern white rhinos from extinction announced on Wednesday that two eggs fertilized 10 days ago have transformed into embryos.
The world’s only remaining rhinos are both females, named Fatu and Najin.
The unprecedented procedure that took place in an Italian laboratory is the last hope in keeping the species from complete extinction.
“After 10 days of incubation, two of Fatu’s eggs have developed into viable embryos that have been cryopreserved for future transfer,” Kenya Wildlife Service (KWS) announced on Twitter.
“(The) entire team has been developing and planning these procedures for years, and this development marks an important breakthrough,” KWS added.
The eggs’ harvesting was carried out for the first time on August 23 in Kenya’s Ol Pejeta Conservancy.
A total of 10 oocytes – five from Najin and five from Fatu, were sent to Avantea laboratories in Cremona, Italy.
The mammals were placed under general anesthetic for an ultrasound-guided procedure which involved a probe to harvest the immature eggs cells from the animals’ ovaries.
Seven of these 10 ovules – four belong to Fatu and three to Najin – managed to be artificially inseminated with frozen sperm from two northern white rhino bulls, Suni and Saut on August 25.
However, only two eggs of Fatu have evolved to embryos.
“Najin’s eggs did not make it to a viable embryo despite the fact that one egg initiated segmentation,” KWS reported.
The embryos will be stored in liquid nitrogen until they are impregnated in a surrogate mother, according to the statement of German Leibniz-Institute for Zoo and Wildlife Research (IZW).
“Five years ago it seemed like the production of a northern white rhino embryo was almost unachievable goal – and today we have them,” said Jan Stejskal, director of Communication and International Projects from Dvur Kralove Zoo, where Najin and Fatu were born.
Meanwhile, Kenya’s Cabinet Secretary for Tourism and Wildlife, Najib Balala, said that the government is sparing no effort in trying to keep the northern white rhinos from becoming extinct, stating, “it has been decade of race against time and we are excited at the progress in reversing the hitherto bleak outlook for the northern white rhino.”
Najin and Fatu, the only two white rhinoceros alive in the world, were transferred in December 2009 from a Czech Zoo to Kenya along with two males, Suni and Sudan.
The relocation aimed to stimulate reproduction by placing the mammals in their natural environment; nonetheless while several attempts at mating were recorded, no pregnancies resulted.
Scientists concluded that the females were not capable of carrying a pregnancy.
Sudan, the father of Najin and grandfather of Fatu, died in 2018 but his sperm was frozen out of the hope that one day the sperm could be used with assisted reproduction techniques.