Dolly exposed as fake clone
Steve Connor is the Science Editor of The Independent. He has won many awards for his journalism, including five-times winner of the prestigious British science writers’ award; the David Perlman Award of the American Geophysical Union; twice commended as specialist journalist of the year in the UK Press Awards; UK health journalist of the year and a special merit award of the European School of Oncology for his investigative journalism. He has a degree in zoology from the University of Oxford and has a special interest in genetics and medical science, human evolution and origins, climate change and the environment.
Tuesday 31 August 1999
Genetic analysis of Dolly's DNA has revealed she is an amalgam of two animals and is therefore a "chimera" with two genetic "mothers" rather than a pure clone.
The explanation lies in the way Dolly was created, by transferring the nucleus of an udder cell from one sheep and inserting it into another ewe's egg cell that had its own nucleus removed. Scientists have found that although all of Dolly's genes within the nucleus of her cells comes from the ewe who supplied the udder cell, the second ewe has contributed the genes of the cell cytoplasm, the part of the cell outside the nucleus.
About 0.02 per cent of a mammal's genes - including humans - exist outside the nucleus in cellular structures called mitochondria, the power-producing parts of the cell which have their own genes.
Analysis of Dolly's mitochondria by Eric Schon, of Columbia University College of Physicians and Surgeons, and Ian Wilmut, of the Roslin Institute near Edinburgh, has confirmed Dolly has two genetic mothers.
The scientists found all of the mitochondria from Dolly and nine other cloned sheep produced by the nuclear-transfer method are derived from the egg cells that received the donated nuclei. In Nature Genetics they say the results are "surprising" because some of the udder cell's cytoplasm and mitochrondrial genes must have been transferred into the enucleated egg cell.
International Women's Day 2014: The shocking statistics that show why it is still so important
Oscar Pistorius trial: The week he went from a hero of his nation and the world, to a gun-loving hothead
International Women’s Day: 'When a man gives his opinion, he's a man. When a woman gives her opinion, she's a bitch' - feminist quotes from female icons to inspire you
Malaysia Airlines plane: Oil slick is first sign that missing flight crashed into sea killing up to 239 on board
International Women's Day 2014: Cherie Blair - ‘Today is a chance to see how far we still have to go’
Britain's top vet sparks controversy with call for ban on slashing animals' throats in 'ritual' slaughters for halal and kosher meat products
Ukraine crisis: Russia dismisses '3am ultimatum' as 'total nonsense'
If you're horrified by a flame-roasted dog, you should be shocked at a hog roast
Poor 'live like animals' says Boris's privately educated sister after going on 'poverty safari'
White people become less racist just by moving to more diverse areas, study finds
Exclusive: Impact of immigrants on British workers ‘negligible’
- 1 To those who can’t see the point of International Women’s Day: you are the very reason it exists
- 2 International Women's Day 2014: The shocking statistics that show why it is still so important
- 3 Orgasm machine to deliver climax at the push of a button
- 4 Singapore sting: Sky-high prices are pushing locals to the edge of affordability
- 5 Liam Neeson turned down James Bond role because late wife Natasha Richardson said she wouldn't marry him if he took it
£12000 per annum: Inspiring Interns: A small but growing chain of boutique hot...
£12000 per annum: Inspiring Interns: The company works with Tier 1 FTSE 100 Ba...
£45 - 60k Per Annum: Charter Selection: Highly profitable leisure brand, marke...
£30000 - £50000 per annum + Highly Competitive Salary: Austen Lloyd: Residenti...