Resurrecting extinct species
The movie Jurassic Park provided the fantasy, and Dolly the sheep gave us the reality, when after more than 200 attempts, a new individual was cloned using the nucleus of an udder cell. Since Dolly, mice, cattle and many other animals have also been successfully cloned.
But, what about those species which have already become extinct? Specimens of these animals (and their DNA) can sometimes be found in alcohol-filled preserving bottles in museum storerooms. Is cloning likely to help resurrect these species?
Cloning is a very inefficient process. Even in the Hawaiian laboratory of Professor Ryuzo Yanagimachi, where the best results have been achieved so far, only 3% of cloned mice embryos survive to birth.
This laboratory has the best possible conditions for mouse cloning and all the relevant knowledge available on the timing of reproduction. In addition, many females can be treated to receive the embryos at the appropriate time in their reproductive cycle.
The laboratory of Professor Yanagimachi now has a population of about 80 cloned mice. These have been cloned using nuclei from tissues including nerves, tail tips and the diffuse cloud of cells which surrounds recently ovulated eggs.
Extracting DNA from an insect trapped in amber, as in Jurassic Park, is a very long way from making a real dinosaur. Despite successful efforts extracting bacteria from insects preserved in amber, it is still only speculation that we could ever extract DNA from the blood sucked by mosquitoes from dinosaurs millions of years ago. Big leaps of technology and skill are still required before creating a dinosaur could be contemplated.
Explore this question with the Natural History Museum in London: http://www.nhm.ac.uk/nature-online/earth/fossils/fathom-dnainamber/the-search-for-dna-in-amber.html