The creation of the first ever hybrid rhino embryo was achieved through the fusion of a southern white rhino egg with northern white rhino sperm that had been obtained from Sudan.
Researchers have successfully developed rhinoceros embryos to the blastocyst stage, which means they are ready for implantation in a surrogate.
Scientists developed a hybrid embryo by combining the sperm of the northern white rhino and the egg of the southern white rhino, which population is now estimated at around 21,000 individuals, according to the zoo statement.
A team of scientists designed a hybrid embryo with the DNA of the almost extinct northern white rhino.
"In the near future we are planning to go to Kenya to retrieve the eggs from the bodies of two female Northern white rhinos".
"It remains unlikely that a viable population of Northern white rhinos will be restored".
"We now see clearly, as ever more, our obligation to not only to help northern white rhinos but to help them to somehow survive in captivity or in human care but later to even help them get back to their original range and be wild again", he told reporters.
For example, in 2011 scientists from the SCRIPPS Institute in La JOLLA (USA) created the first stem cells of the extinct Northern white rhinos and endangered species of baboons-drylaw using samples of their frozen tissues.
They believe that the embryos could be transferred to female southern white rhinoceroses, who would give birth to hybrid calves. "They have a very high chance to establish a pregnancy once implanted into a surrogate mother", Hildebrandt said in a statement. "Meanwhile, we don't have enough funding to conserve the other four rhino species, all of which are more threatened with extinction than the white rhino", said Bob Smith, Director of the Durrell Institute of Conservation and Ecology at the University of Kent, England.
"They showed that oocytes can be repeatedly recovered from live females by this trans-rectal ovum pick-up, matured, fertilised by intracytoplasmic sperm injection (ICSI) and, for the first time, developed to the blastocyst stage in vitro".
According to Thomas Hildebrandt who led the work published in the journal Nature Communications, it's a race against time.
As for the female eggs, they were taken from the southern white rhinoceros from several European zoo parks, including the Dvur Kralove Zoo. The procedure was performed on a femalesouthern white rhino but while under a general anesthetic because the procedure is very risky.
"A single northern white rhino calf would be a wonderful scientific achievement, and a hope for the future, but that is not the end goal", Durrant said.
Because of the many biological and technological uncertainties that dot the leap from an embryo to a healthy rhino baby, scientists are looking into a years-long process and mulling different possibilities. They plan to use chemical and genetic techniques to transform these ordinary skin cells into more cells resembling embryonic stem cells.
ART was created by a team led by Cesare Galli, a veterinarian, and embryologist working at Avantea, a biotechnology laboratory in Italy. "We are quite confident with the technology we have developed".
Terri Roth and William Swanson of the Cincinnati Zoo and Botanical Garden, in a comment on the study, said ART alone can not save a species from extinction.