article: But is it possible dragons could ever exist beyond the pages of Celtic mythology or the celluloid of fantasy film? Academics have suggested in a recent essay the creation of large, winged dragons using cutting-edge genome editing is not beyond the realms of possibility. Is the seemingly far-fetched idea a flier or, like dragon's breath, just hot air? The BBC asked the authors. The essay in The American Journal of Bioethics said spectacular animals could be brought to life using a targeted gene-editing system known as CRISPR-CAS9. Co-authors Prof Hank T Greely, director of the Centre for Law and the Biosciences at Stanford Law School, and Prof R Alta Charo, Professor of Bioethics and Law at Wisconsin Law School, said their dragon suggestion was "somewhat tongue-in-cheek" but "not impossible". "There are the possibilities of spectacles," they wrote. "Animals and plants not created for personal use but to be exhibited. "Consider, for example, the dragon. Basic physics will almost certainly combine with biological constraints to prevent the creation of flying or fire-breathing dragons. "But a very large reptile that looks at least somewhat like the European or Asian dragon (perhaps with flappable if not flyable wings) could be someone's target of opportunity." And it may not be as improbable as it seems at first blush. CRISPR and other similar techniques involve DNA being inserted, replaced, or removed from a genome using artificially engineered nucleases. The method has been adopted by scientists around the world. CRISPRs (clustered regularly interspaced short palindromic repeats) are sections of DNA, while CAS-9 (CRISPR-associated protein 9) is an enzyme. They are found in bacteria, which use them to disable attacks from viruses. They have led to the creation of patented "GloFish" that shine under UV light, the eradication of horns from certain cattle species, manipulation of crops and attempts to produce hypo-allergenic cats. Artist Eduardo Kac even commissioned a French geneticist to create Alba, a genetically modified "glowing" rabbit. Debate has raged over whether CRISPR, which occurs as part of a bacterial process, could be safely and ethically used on humans since 2012. But professors Greely and Charo argue its potential to produce "CRISPR critters" is "likely to be overlooked" by legislators and regulators "because they are unexpected". The method is "cheaper and easier" than older forms of genetic engineering and can be done "outside the traditional laboratory setting". Their essay looks at the possible uses of CRISPR for de-extinction of wild species - such as 700,000-year-old horses - for domestic de-extinction - such as tomato species - and for making creatures of "personal whim". They point out that Harvard geneticist George Church is using CRISPR to edit Asian elephant cell lines to give them some woolly mammoth genes. Asked about the likelihood of dragons, the co-authors said: "We imagine it would be low although not impossible with respect to appearance (the fire-breathing and flying aspects are undoubtedly beyond any plausible genetic engineering). "In the US, the determining factor is usually cost as compared to return-on-investment, where cost can be substantial given the regulatory hurdles. "Does this mean some
summary: The mythical dragon has been associated with Wales for more than a millennium and famously graces the national flag.