Northern White Rhino is resurrecting
There are only two females left today, but fortunately, scientists have found the parade. The death of the last male specimen seemed to condemn the African species. However, a boost from genetics may well save it.
Last March, Sudan, the last male representative of the northern white rhinos, once widespread in Congo, Uganda, Chad, and Sudan, died of old age on the Ol Pejeta Reserve at the foot of Mount Kenya.
His death almost condemns this subspecies of rhinos to extinction, since only two females are still alive, the daughter and granddaughter of Sudan.
The survival of northern white rhinos is not unthinkable. One of the causes of the rarefaction of this animal is its difficulty to reproduce. So far, in vitro fertilization attempts have been unsuccessful.
However, as Nature magazine has just revealed, a team of German scientists from the Berlin Zoological and Animal Research Institute Leibniz, led by Thomas Hildebrandt, succeeded in fertilizing an oocyte of a southern female rhinoceros with sperm. Frozen northern rhino, creating the first in vitro embryo of white rhinoceros. Southern ones are less rare and are mainly found in south Africa.
To collect oocytes, scientists had to develop a special tool. Once the southern female reproductive cells were extracted, they were sent to the Italian laboratory Avantea, which performed the first in vitro fertilization of rhinoceros. The embryos thus created, which have been frozen, are therefore hybrids of both subspecies.
“Our goal is to see, within three years, the birth of the first white rhinoceros in the North,” says Thomas Hildebrandt. The embryo would be implanted in a female of the southern subspecies, the two females of the North cannot carry the fertilized eggs directly, because of health problems.
On the other hand, at the end of the sixteen months of gestation, the scientists hope to entrust the possible small rhinoceros to the guard of the two females of the North so that they can “teach them the social life of this subspecies”, specifies the scientist.
Source : Stockunlimited
Stem cells to the rescue
The next step in this process will be to collect oocytes directly from the two surviving females in the North to create embryos that are not hybrids, but only from individuals in the Northern subspecies. However, such a mode of reproduction would not make it possible to revive a species in a viable way.
Since individuals are limited in number, the genetic diversity of “produced” beings would also be reduced. The solution envisaged? Use stem cells to improve genetic wealth. These cells are pluripotent, that is, they are not yet specialized, and can become any type of cell.
It would be a question of programming stem cells taken from Northern white rhinoceroses to make them embryonic cells. The eggs thus created would be fertilized by sperm preserved by the team of Thomas Hildebrandt. What, in theory, produce viable and fertile descendants.
However, the rebirth of the species will not be enough to ensure its survival. Despite large numbers of wild animals in the 1960s, in the order of 1,000 individuals, wars and poaching quickly decimated the white rhinoceros population in the north.
The subspecies of the South, at the beginning of the century, after coming close to extinction, benefited from great preservation efforts, which made it possible to ensure its preservation. There are about 20,000 individuals in the wild, the vast majority of them in South Africa.
Contrary to what one might think, the conservation project for northern white rhinoceros does not benefit from significant institutional support.
To finance themselves, the scientists of the project have set up a call for donations on the site of the Leibniz Institute for Zoological and Animal Research.
As he told Britain’s Guardian shortly after the death of Sudan, Thomas Hildebrandt believes that the survival of these rhinos is crucial: “We do not know what the long-term effect on the ecosystem will be, but we certainly upset him by removing such an animal.”