IVF may bring northern white rhinos back from the brink of extinction

SUDAN, the last male northern white rhinoceros on Earth, died in March. He is survived by two females, Najin and her daughter Fatu, who live in a conservancy in Kenya. This pair (pictured) are thus the only remaining members of the world’s most endangered subspecies of mammal. But all might not yet be lost. Thomas Hildebrandt of the Leibniz Institute for Zoo and Wildlife Research, in Berlin, in collaboration with Avantea, a biotechnology company in Cremona, Italy, is proposing heroic measures to keep the subspecies alive. In a paper just published in Nature, he and his colleagues say that they have created, by in vitro fertilisation (IVF), apparently viable hybrid embryos of northern white rhinos and their cousins from the south. This, they hope, will pave the way for the creation of pure northern-white embryos.

IVF seems the last hope for the northern white rhino. Though stored sperm from Sudan and several other males are available, both Najin and Fatu now seem unable to conceive. This means, if the subspecies is to be preserved, that one or both of them will have to have some eggs removed from their ovaries and combined with stored sperm in a Petri dish.