Science 'rescues' rhinos: frozen embryos to save them from extinction

The last hope for saving the northern white rhino from extinction, an almost inexorable process for which humans bear specific responsibility, starting with poaching, now comes from surrogacy.
Barely two specimens of the subspecies remain alive: so an international team of scientists and conservationists, including theUniversity of Padua, has worked to achieve the world's first pregnancy in a rhinoceros as a result of embryo transfer.
The southern white rhino embryo was produced in vitro from collected oocytes and sperm and was transferred into a surrogate southern white rhino mother, a subspecies very close to the northern white rhino, at the Ol Pejeta Conservancy in Kenya on Sept. 24, 2023.
The "BioRescue" team - that is the name of the international project - thus confirmed a 70-day pregnancy with a well-developed male embryo 6.4 cm in length. Although the pregnancy was not carried to term, due to the death of the animal from the consequences of a bacterial infection, the successful embryo transfer and initiation of the pregnancy itself represent - according to the researchers - a proof of concept and allow them to safely move on to northern white rhino embryo transfer, a milestone in the mission to save the northern white rhino from extinction.
And so hope is kindled for the world's last two northern white rhinos, the female Najin and her daughter Fatu, kept in an ad hoc area in Kenya. Live cells from 12 different northern white rhino individuals, preserved in liquid nitrogen, could soon give their subspecies a new lease on life.