PRAGUE Czech Republic (Xinhua) --
An international team of scientists and
zoologists from Germany, Italy and the Czech Republic managed to
artificially develop an embryo of the northern white rhinos,
virtually extinct mammals with no living male existent, a Czech
zoo said Wednesday in a statement.
At the moment, there
are only two known rhinos of this subspecies left alive. Both of
them are females, which makes the northern white rhinoceros
animals—named Najin and her daugther Fatu—live in the Ol Pejeta
Conservancy in Kenya and belong to the Dvur Kralove Zoo in the
a hybrid embryo by combining the sperm of the northern white
rhino and the egg of the southern white rhino, which population
is currently estimated at around 21,000 individuals, according
to the zoo statement.
this is the first case when the blastocyst, the early stage of
embryo development, has been achieved at the laboratory.
Director of the Dvur
Kralove Zoo Premysl Rabas said it was a real breakthrough to
rescue the critically endangered animal.
methods of reproduction is a major step towards the birth of the
first northern white rhino baby. In fact, half of the genetic
information of this hybrid embryo comes from the white northern
rhinoceros, which is an amazing success,” Rabas was quoted as
head of the Department of Reproduction Management at the
Berlin-based Leibniz Institute for Zoo and Wildlife Research (IZW),
said that the progress could be a great chance that after
embryos are inserted into the womb of the surrogate mother, this
female will be pregnant.
In order to create a
hybrid embryo, the team of scientists used an adapted technique
of artificial insemination of horses.
Frozen samples of
sperm from the last male species of the northern white rhino in
the world, named Sudan who died in March this year in Kenya at
old age, were used to produce the embryo.
As for the female
eggs, they were taken from the southern white rhinoceros from
several European zoo parks, including the Dvur Kralove Zoo. For
safe collection of female bio-material, the zoologists used a
recently patented instrument with a length of nearly two meters.
The female eggs
ended in the laboratory of Avantea in Italy, the world’s leader
in artificial reproduction for large animals.
“In our laboratory,
we have developed methods in order to mature the eggs and its
fertilization [...] using a microneedle inserted into the
cytoplasm of the egg,” said a representative Cesare Galli from
“As for the cattle
or horses, these methods have been applied for a long time, but
it has been the first time with rhinos, when the blastocyst was
successfully created,” said the representative.
Several embryos are
now frozen and preserved for future insertion into surrogate
Now scientists face
another challenge of getting female eggs from the last two
females living in Kenya in order to create a clean embryo.
Zoologist say that
due to the fact that the number of genuine reproduction material
of northern white rhinos is limited to four individual donors,
this dramatically narrows down the base required to create a
viable population for maintaining sufficient genetic diversity.
That is why
scientists, alongside with artificial reproduction methods, also
work on stem cells development derived from the stem cells
obtained from the northern white rhinoceros that have been
preserved in the past.
“We are now able to
acquire embryonic stem cells related to southern white
rhinoceroses that contain all the properties of an
undifferentiated cell with a high ability to differentiate,”
The combination of
stem cell research with newly developed artificial insemination
technology provides scientists with a way to save critically
endangered mammalian species.