‘Extinct’ rhino may be brought back to life
They may look like meaningless blobs, but tiny sacs of cells hold the embryo of a northern white rhino – and the future of an entire subspecies.
The northern white rhino has been effectively extinct since 2018, when the last male, 45-year-old Sudan, died in Kenya.
Since the 1960s, the population has fallen from 2000 to just two remaining females today – mother Najin and daughter Fatu – who are protected at Ol Pejeta Conservancy near Mount Kenya.
But now scientists have taken nine eggs from the females and fertilised them with sperm from a dead male, successfully creating three viable embryos which they are hoping to implant into a surrogate later this year.
All three embryos are being stored in liquid nitrogen while conservationists hunt for a suitable female to carry the precious calves.
The team is hoping to implant the embryos into young, fertile southern white rhinos, as it is too risky to carry out the procedure on the last remaining northerns.
The gestation period for rhinos is up to 18 months, meaning the first calf could be born by 2022.
Najib Balala, Kenya’s secretary for tourism, said: ‘‘The Kenyan government is delighted that the Northern White Rhino IVF project has been able to successfully produce three pure northern white rhino embryos ready for implantation into the southern white rhino as surrogate in the coming months.
‘‘This is a big win for Kenya and the northern white rhino, which is faced with imminent extinction, where only two of them are left in the world.
‘‘It is a delicate process, and we thank the concerned parties for putting in all their efforts to ensure that a critically endangered species does not disappear from the planet under our watch. It is amazing to see that we will be able to reverse the tragic loss of this subspecies through science.’’
Northern white rhinos are the most endangered mammal on Earth. Until now, all efforts to save them have been thwarted by poaching, civil war and habitat loss. The project to revive the population has been ongoing for several years.
The task of taking egg cells from a rhino had never been attempted before, and scientists had to invent a special two-metre device to stimulate the female’s ovaries and collect the oocytes.
Researchers say the creation of three pure northern embryos is a ‘‘hugely encouraging milestone’’ for the species, and was accomplished using a safe procedure which can be performed on a regular basis until the animals get too old.
Following fertilisation, the embryos were monitored in a special incubator, dubbed Geri, supplied by German pharmaceutical company Merck.
The scientists are also trying to create rhino sperm and eggs directly from stem cells.
Because there are only two females left and all the available semen comes from only four males, IVF alone would not be able to create a self-sustaining population of northern white rhinos with the necessary genetic diversity.
To get around this, scientists are working on producing artificial gametes – egg and sperm – from the preserved ear tissue of 12 dead white rhinos.
The scientists say the work creates a blueprint for how to save endangered species – even those which are already extinct. Once they have a viable population, the rhinos will be taken back to central Africa. – Telegraph Group