South Korea's pioneering stem cell scientist has cloned a dog, smashing another biological barrier and reigniting a fierce ethical debate - while producing a perky, lovable puppy.
The researchers, led by Hwang Woo-suk, insist they cloned an Afghan hound, a resplendent supermodel in a world of mutts, only to help investigate human disease, including the possibility of cloning stem cells for treatment purposes.
But others immediately renewed calls for a global ban on human reproductive cloning before the technology moves any farther.
"Successful cloning of an increasing number of species confirms the general impression that it would be possible to clone any mammalian species, including humans," said Ian Wilmut, a reproductive biologist at the University of Edinburgh who produced the first cloned mammal, Dolly the sheep, from an adult cell nearly a decade ago.
Researchers have since cloned cats, goats, cows, mice, pigs, rabbits, horses, deer, mules and gaur, a large wild ox of Southeast Asia. So far, efforts to clone a monkey or another primate with the same techniques have failed.
Uncertainties about the health and life span of cloned animals persist; Dolly died prematurely in 2003 after developing cancer and arthritis.
Wilmut and others complimented Hwang's achievement, reported Wednesday in the journal Nature. But they said politicians and scientists must face the larger and more delicate issue - how to extend research without crossing the moral boundary of duplicating human life in the lab.
"The ability to use the underlying technology in developing research models and eventually therapies is incredibly promising," said Robert Schenken, president of the American Society for Reproductive Medicine. "However, the paper also points out that in dogs as in most species, cloning for reproductive purposes is unsafe."
The cloned puppy was the lone success from more than 100 dogs implanted with more than 1,000 cloned embryos.
In a news conference in Seoul, the cloning team also condemned the reproductive cloning of humans as "unsafe and inefficient." Human reproductive cloning already is banned in South Korea. Other nations, including the United States, are split over whether to ban just human cloning or cloning of all kinds, including the production of stem cells.
韓國倡導干細胞研究的科學家們成功克隆了一只狗，這只活潑可愛的小狗的克隆成功不僅突破了生物學上的又一座壁壘，也再次引發(fā)了一場有關倫理道德觀念的激烈爭論。
以黃禹錫為首的研究員們堅持認為，他們克隆這只阿富汗獵犬（世界上非常有名的雜交犬種），僅僅是為了為研究人類疾病提供幫助，出于治療的目的，他們可能會克隆干細胞。
不過立刻有人再次呼吁，在科技水平尚未成熟之前，全世界應禁止克隆人。
愛丁堡大學再生生物學家伊恩·維爾莫特稱：“成功克隆越來越多的物種證明所有哺乳動物都是可能被克隆的，包括人類本身?！本S爾莫特是第一個克隆哺乳動物的科學家，10年前他成功利用成體細胞克隆了綿羊多莉。
此后研究人員還克隆了貓、山羊、牛、老鼠、豬、兔子、馬、鹿、騾及白肢野牛（東南亞地區(qū)一種大野牛）。迄今為止，用同樣方法克隆猴子或其他靈長類動物的嘗試均以失敗告終。
有關克隆動物的健康狀況及生命周期仍存在不確定性；綿羊多莉2003年就曾因癌癥及關節(jié)炎過早死去。
本周三出版的世界科學雜志《自然》報道稱，維爾莫特和其他一些科學家都稱贊黃禹錫取得的成功，不過他們也表示，政治家和科學家必須面對一個更棘手的問題：如何才能在實驗室中不跨越克隆人的道德邊界去拓展現(xiàn)在的研究。
美國再生醫(yī)藥學會總裁羅伯特·沈肯指出，利用潛在的科學技術去發(fā)展研究模式，并將其最終用于治療，這肯定很有希望的，不過，論文中也指出了狗是一種太常見的物種，用它來進行克隆再生不太安全。"
研究人員曾把1000多個克隆胚胎植入100多只狗體內，但只有一只獲得成功。
在首爾舉行的記者招待會上，克隆團隊還受到了指責，人類進行再生克隆是"不安全的，低效的"。韓國已經明令禁止人類再生克隆。其他一些國家，包括美國，則在是否要禁止克隆人還是禁止克隆所有物種，包括克隆干細胞上，存在分歧。
The researchers, led by Hwang Woo-suk, insist they cloned an Afghan hound, a resplendent supermodel in a world of mutts, only to help investigate human disease, including the possibility of cloning stem cells for treatment purposes.
But others immediately renewed calls for a global ban on human reproductive cloning before the technology moves any farther.
"Successful cloning of an increasing number of species confirms the general impression that it would be possible to clone any mammalian species, including humans," said Ian Wilmut, a reproductive biologist at the University of Edinburgh who produced the first cloned mammal, Dolly the sheep, from an adult cell nearly a decade ago.
Researchers have since cloned cats, goats, cows, mice, pigs, rabbits, horses, deer, mules and gaur, a large wild ox of Southeast Asia. So far, efforts to clone a monkey or another primate with the same techniques have failed.
Uncertainties about the health and life span of cloned animals persist; Dolly died prematurely in 2003 after developing cancer and arthritis.
Wilmut and others complimented Hwang's achievement, reported Wednesday in the journal Nature. But they said politicians and scientists must face the larger and more delicate issue - how to extend research without crossing the moral boundary of duplicating human life in the lab.
"The ability to use the underlying technology in developing research models and eventually therapies is incredibly promising," said Robert Schenken, president of the American Society for Reproductive Medicine. "However, the paper also points out that in dogs as in most species, cloning for reproductive purposes is unsafe."
The cloned puppy was the lone success from more than 100 dogs implanted with more than 1,000 cloned embryos.
In a news conference in Seoul, the cloning team also condemned the reproductive cloning of humans as "unsafe and inefficient." Human reproductive cloning already is banned in South Korea. Other nations, including the United States, are split over whether to ban just human cloning or cloning of all kinds, including the production of stem cells.
韓國倡導干細胞研究的科學家們成功克隆了一只狗，這只活潑可愛的小狗的克隆成功不僅突破了生物學上的又一座壁壘，也再次引發(fā)了一場有關倫理道德觀念的激烈爭論。
以黃禹錫為首的研究員們堅持認為，他們克隆這只阿富汗獵犬（世界上非常有名的雜交犬種），僅僅是為了為研究人類疾病提供幫助，出于治療的目的，他們可能會克隆干細胞。
不過立刻有人再次呼吁，在科技水平尚未成熟之前，全世界應禁止克隆人。
愛丁堡大學再生生物學家伊恩·維爾莫特稱：“成功克隆越來越多的物種證明所有哺乳動物都是可能被克隆的，包括人類本身?！本S爾莫特是第一個克隆哺乳動物的科學家，10年前他成功利用成體細胞克隆了綿羊多莉。
此后研究人員還克隆了貓、山羊、牛、老鼠、豬、兔子、馬、鹿、騾及白肢野牛（東南亞地區(qū)一種大野牛）。迄今為止，用同樣方法克隆猴子或其他靈長類動物的嘗試均以失敗告終。
有關克隆動物的健康狀況及生命周期仍存在不確定性；綿羊多莉2003年就曾因癌癥及關節(jié)炎過早死去。
本周三出版的世界科學雜志《自然》報道稱，維爾莫特和其他一些科學家都稱贊黃禹錫取得的成功，不過他們也表示，政治家和科學家必須面對一個更棘手的問題：如何才能在實驗室中不跨越克隆人的道德邊界去拓展現(xiàn)在的研究。
美國再生醫(yī)藥學會總裁羅伯特·沈肯指出，利用潛在的科學技術去發(fā)展研究模式，并將其最終用于治療，這肯定很有希望的，不過，論文中也指出了狗是一種太常見的物種，用它來進行克隆再生不太安全。"
研究人員曾把1000多個克隆胚胎植入100多只狗體內，但只有一只獲得成功。
在首爾舉行的記者招待會上，克隆團隊還受到了指責，人類進行再生克隆是"不安全的，低效的"。韓國已經明令禁止人類再生克隆。其他一些國家，包括美國，則在是否要禁止克隆人還是禁止克隆所有物種，包括克隆干細胞上，存在分歧。