The third will be

The third viable embryo of the northern white rhinoceros was obtained

Elizaveta Ivtushok, N+1

European scientists have managed to obtain another viable embryo of the northern white rhinoceros: they fertilized with sperm cells of the male Suni, who died in 2014, the egg of the female Fatu, who is still alive. Now there are three embryos: they are contained in liquid nitrogen, and the first attempt at transplantation of a surrogate mother can be carried out this year. This is reported on the website Institute of Zoology and Wildlife of the Leibniz Association.

From the 1960s to the 1980s, the population of northern white rhinos decreased from several thousand individuals to only 15. Despite attempts to restore the population in nature reserves (no rhinos have been seen in the wild since 2007), by the early 2010s there were even fewer rhinos: in 2014 two of the three remaining males died, and in 2018 the last of them, Sudan, died.

Now there are only two northern white rhinos left in the world — the females Najin and Fatu. Scientists, however, are making attempts to restore the animal population using artificial insemination and to use the frozen spermatozoa of the last three males of the northern white rhinoceros for this purpose. Experiments to restore the population began last summer, and in the fall, scientists from the Institute of Zoology and Wildlife of the Leibniz Association and the Avantea Laboratory of Reproductive Technologies managed to obtain two viable embryos.

The survival rate of embryos, however, is not so high yet: two viable ones were obtained from ten extracted eggs. That is why scientists continue experiments on in vitro fertilization. 

Now it has become known that in December the same group of scientists managed to obtain another viable embryo. To do this, they extracted nine eggs from Najin and Fatu, and then fertilized them with the sperm of a male Suni, who died in 2014. One of Fatou's fertilized eggs developed into an embryo.

Now all three living embryos are contained in liquid nitrogen. To restore the population of northern white rhinos, scientists will have to rely on surrogate motherhood. Despite the fact that additional studies will need to be carried out before embryo transplantation, scientists plan to make the first attempts this year.

Most likely, the surrogates will be females of a close relative of the animal, the southern white rhinoceros. Last summer, one of them already managed to give birth to a cub after artificial insemination.

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