Scientists on Monday announced the successful fertilisation of Northern white rhino eggs to perpetuate the almost extinct species.
Only two Northern subspecies rhinos were in existence last year. Both (Fatu, 18 and Najin, 29) are females and in captivity.
Sudan, the world's last known male Northern white rhinoceros, died in Kenya on March 19, last year.
Scientists successfully harvested 10 eggs from Najin and Fatu on August 22 in Kenya.
On Monday, the International Consortium of Scientists and Conservationists announced that seven out of the 10 eggs (four from Fatu and three from Najin) have successfully matured and are artificially inseminated.
This was achieved through Intra Cytoplasm Sperm Injection (ICSI) on August 25 with frozen sperm from two different Northern white rhino bulls; Suni and Saut.
"This is the next critical step in hopefully creating viable embryos that can be frozen and then later on transferred to Southern white rhino surrogate mothers," the scientists said in a statement.
The high rate of the maturation recorded was miraculous, they said, "as we do not get such levels (comparable to what we get with horse oocytes) with Southern white rhino females in European zoos".
They reported that Saut's semen was difficult to work with, hence they had to thaw two batches of semen to find three live sperm needed for the eggs of Najin.
Next move
"We need to wait to see if any viable embryo develops to the stage where it can be cryopreserved for later transfer," Cesare Galli said.
The results of possible embryo development are set to be known on September 10.
The research programme known as BioRescue is funded by the German Federal Ministry of Education and Research.
Edited by R.Wamochie
