Word: cloned
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Dates: during 2000-2009
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...Hwang's claims create such excitement? In a 2004 paper, Hwang reported that his team was the first to clone human embryos and extract lines of embryonic stem cells (ESCs) from them, harvesting a single line of ESCs from experiments involving 248 human eggs. ESCs can potentially grow into any type of body tissue, and lines created through cloning might one day help treat conditions like Alzheimer's or diabetes without the risk of immune rejection. In 2005, Hwang claimed to improve his process, using an average of 17 eggs to create an ESC line...
With Hwang's scientific credibility in shambles, the status of the world's most famous dog hangs in the balance. The embattled scientist maintains that Snuppy is the world's first canine clone, and he even hired an independent Korean DNA lab, HumanPass Inc., to verify that assertion. The verdict: HumanPass CEO Seung Jae Rhee told TIME last week, "There is no dispute about these results, and so I am 100% certain on Snuppy's authenticity." But since HumanPass is in essence working for Hwang, that's hardly good enough for the investigative panel at Seoul National University, which...
...Snuppy really was cloned from the ear cell of a 3-year-old male Afghan named Tai, it shouldn't be tough to prove, even to those outside investigators. As long as they have tissue samples from both the clone and the parent, they should be able to determine whether DNA in the nuclei of both animals' cells is identical--the first hallmark of a true clone. Ian Wilmut, the Scottish scientist who created Dolly the sheep in 1996, had to provide such samples to prove to skeptics that he had created history's first mammalian clone...
Mitochondrial DNA is passed down from the mother as part of the egg's genetic contribution. Identical twins, for example, have the same nuclear and mitochondrial DNA, since they're produced when a single egg is fertilized and the resulting embryo splits in two. With a clone, the situation is different. Because the cloning process that Hwang says he used to create Snuppy involves two dogs--one for the nucleus and another for the egg--Snuppy's mitochondrial DNA should not match Tai's. That's what Rhee's scientists say they've found and what Hwang undoubtedly hopes...
Evidently, the risk-taking began in 2004, with Hwang's first major scientific paper on therapeutic cloning. In order to clone an adult, you need to put one of its cells into a human egg cell from which the nucleus has been removed. After electrical fusion and chemical activation, the egg can then start dividing, creating embryonic stem cells. (If left to mature, the embryo could eventually grow into a clone of the original adult--something no reputable scientist would let happen...