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)
