Chinese scientists expect the world's first rabbit cloned by
using a biological process that takes cells from a fetus will be
able to reproduce in three months.
The genetically-modified cloned rabbit glows green under a
fluoroscope, a result of being injected with special genes.
Scientists hope this special trait will be transferred to the
rabbit's offspring.
The unnamed female rabbit, born in a hospital affiliated to
Shanghai Jiaotong University's medical school on September 14,
weighed 1.4 kilograms when three months old, the average age for
rabbits to enter puberty, said Chen Xuejin, an associated professor
with Jiaotong University's medical school.
For safety considerations, he said the rabbit would not start
mating until it was six months old.
The rabbit is the world's first to be cloned using "fibroblast"
cells from a fetal rabbit and will be used to research causes of
human diseases, said Chen, head of the research team.
The cloned rabbit (front)
is obviously larger than its peers. (photo: sina.com.cn)
Chen and his colleagues began the test by extracting glowing
protein genes from a jellyfish. The gene was transplanted into the
rabbit's fiber cells before the genetically-modified cell was
injected into a rabbit embryo.
They then placed the reconstructed embryo into the uterus of a
female rabbit. After 30 days of gestation, the cloned creation was
born through caesarean section.
Researchers found a rabbit which had just given birth and put
the cloned bunny in the same cage as her and the other newborns.
The cloned rabbit ate radish and green vegetables like its
peers.
Chen said his research team had produced other rabbits using the
same technology, but most of them had died shortly after being
born.
"Even the longest surviving cloned bunny didn't outlive the
weaning age, around the fifth week," he said.
As rabbits share similar genes with humans, the
genetically-modified cloned rabbit is expected to be used for
research into cardiovascular and eye diseases as well as some
genetic ailments, said Dr. Li Shangang with the Chinese Academy of
Agricultural Sciences.
Scientists have cloned mice, cattle and other animals since the
first cloned sheep, Dolly, was born in 1996. Malaysia is trying to
clone some of its threatened leatherback turtles to save them from
extinction.
But it was only in 2002 that French scientists produced the
world's first cloned rabbit using cells from an adult female
rabbit.
(Xinhua News Agency December 19, 2007)