Is Snuppy the Puppy for Real?
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, Human Pass Inc, to verify that assertion. The verdict: Human Pass 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 Human Pass is in essence working for Hwang, that s hardly good enough for the investigative panel at Seoul National University, which is carrying out independent tests, or for the editors of Nature, who have ordered an investigation.
If 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.
Even with the controversy raging over his stem-cell paper, Hwang could have forestalled some of the questions about Snuppy if he had offered one additional bit of confirming proof in his original paper in Nature. That piece of critical evidence comes from the animals mitochondria, tiny energy-producing structures within each cell. While most of a mammal s DNA resides in the nucleus, there s also some in the mitochondria.
Mitochondrial DNA is passed down from the mother as gart 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 the university and Nature will find as well. Final, ironclad proof of Snuppys provenance would involve showing that the dog s mitochondrial DNA matches that of his egg donor .It s not clear, however, whether that test is being done.
开心学英语四下《Unit 2 Are you dancing》word教案(2)
上海本地版英语三上《Unit 11 Small animals》教案
开心学英语四下《Unit 5 Where are you going》word教案(1)
开心学英语四上《Unit 1 Hi, Gogo!》word教案(1)
外研版英语四上《Module 3 Activities》(unit1)word教案
开心学英语四下《Unit 7 I like eating》word教案(1)
开心学英语四上《Unit 7 Where are my glasses》word教案之一
2014秋湘少版英语三上《Unit 2 Good morning》word第3课时教案
外研版(一起)第七册Module 3《Unit 2 I didn’t play football》word教案
外研版英语四下《Module 2 London》(unit2)word教案
[2013秋]人教版(PEP)四上《Unit 2 My Schoolbag》word教案
外研版英语四下《Module 4 Robots》(unit1)word教案
[2013秋]人教版(PEP)四上《Unit 6 Meet My Family》(第1课时)word教案
北师大版四年级下册英语教案
外研版英语四上《Module 7 Travel》(unit1)word教案2篇
开心学英语四上《Unit 3 Can I have a balloon》word教案之一
深港版英语四下《Unit 3 Seasons》word学案
外研版英语四上《Module 9 Happy Birthday》(unit1)word教案
2015秋人教版小学英语四年级上册第三单元表格式导学案
开心学英语四上《Unit 6 What do they want》word教案
开心学英语四下《Unit 11 I’m a doctor》word教案(2)
人教版新课标小学英语四年级教案(Unit 4 My home)
小学PEP新教材四年级下册英语教案
上海本地版英语三上《Unit 3 How old are you》教案
外研版英语四上《Module 8 Sports Day》(unit2)word教案
外研版英语四上《Module 2 Directions》(unit2)word教案
人教(新版)英语四下《Fun Time 1 Part 1》word教案
外研版英语四下《Module 1 Friends》(unit1)word教案
小学PEP新教材四年级下册英语教学计划
开心学英语四下《Unit 5 Where are you going》word教案(3)
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |