The latest attempt to save the northern white rhino from extinction
Sudan – the world’s last male northern white rhino was put to sleep in March this year. Only two females of this subspecies are left alive. Scientists have made a last-ditch attempt to save these animals using modern in vitro fertilization techniques and stem cells.
White rhinos pórhinos once roamed the vast areas of Chad, Sudan, Uganda, Congo and the Central African Republic. Their population was dramatically depleted as a result of the conflictóin the armed forces, whichóre have swept through the region in recent decades.
GwóThe coffin was nailed by poachers. Massive hunting of rhinos for horn, który are believed by folklore to have healing properties, have brought rhinos to the brink of extinction. As recently as 2000, 32 individuals of the subspecies were walking around the world.
White rhinoceros póThe northern elk has no natural enemiesóin addition to human. Currently, only two females of this subspecies are still alive – córka and granddaughter of Sudan. They are 17-year-old Fatu and 27-year-old Najin. They are staying in the reserveów and are protected from poachers 24 hours a day by armed men.
Although Sudan is gone, the possibility of saving the rhino still existsóin white póNorthern white rhinos before extinction. This can be done through modern in vitro techniques and the use of stored rhino semenów. The technique of induced pluripotent cellsóThe mother shark also carries some hope.
Próto save the rhinoów was undertaken by an international team ofół researchers. To begin with, they created hybrid rhino embryosów. Their efforts have been described and published on „Nature Communications”.
Veterinarians had already successfully used in vitro fertilization in horses, cattle and other livestock, but never in animals as large as white rhinos. The technique was first used to create rhino embryosów. Researchers have used rhino eggsóin southern whites, a closely related subspecies to white rhinos póNorth. Their population is about 20,000 individualsów.
Rhino genetic materialóIn white póThe North was collected for several years. In banks of comórek stored semen or próbki skóry. Collection of sperm or skóry is a relatively easy task. Egg retrieval from a female rhinoceros proved to be a problem.
Researchers have designed, made and also patented a special instrument thatóry inserted through the anesthetized female’s anus, managed to retrieve eggs. The technique has been tested on female rhinocerosesóin the southern white. Any anesthesia has risks, so the researchers preferred not to test the technique on the last twoóch female white rhinoceros pónorthern. In addition, both females have fertility problems.
From 13 eggs, whichórym injected with white rhino sperm pónnight, four developed into blastocysts – early embryos. In this wayób hybrid embryos containing genes from both subspecies were createdów. They have been frozen for future implantation. It will be possible to transfer these embryosóin to female rhinocerosóin the southern whites.
– This is a very ambitious and bold project to save someóre of the genóin this spectacular animal – said Stuart Pimm of Duke University, whoóry was not involved in the research work. Other researchers also acknowledge that this is currently the only way to preserve at least part of the genome of this subspecies.
But scientists are not giving up. They now want to take eggs from Najin and Fatu and fertilize them with white rhino semen póNorth. The next step will be to implant an embryo of a female southern white rhino. Researchers want to achieve this within three years.
This, however, does not change the fact that rhinos will miss rógenetic diversity to maintain a healthy population of. Another possibility is provided by the technique of induced puripotent cellsóstem (iPS) records, that is, those from which theórych any other cell can be formedórka of the body.
Work in this direction was initiated even before the death of the Sudanese. In 2011, Jeanne Loring and a team of researchers at the Scripps Research Institute in California, created such comórki with skóry Fatu. Since then, Loring and her teamół have created 4 more lines of comóiPS records from the tissue of 12 rhinosóin white pórhinoceros sperm stored at the San Diego Zoo.
In May, scientists showed that this tissue contains enough rógenetic diversity to helpóc save these giant animals. It may be possible to save the subspecies, but the reason for this remains unsolved.
– We still live in a world in whichórym poachers have culled huge numbers of rhinoów. We have a chance to restoreóck the offspring of the rhinoóin white pórhinos into the wild, but we will have to prevent their deaths – admitted Pimm.