Australian researchers have succeeded in inserting in the mouse a gene of an animal that no longer exists, thus discovering what information is contained in that fraction of genetic code. It was already possible to map the DNA of some extinct life forms, but this study will help to understand what the functions of individual genes are. (Susanna Trave, 12 June 2008)
Once the DNA is isolated, from a living being or even from an extinct animal, today it seems to be no longer a problem to map the genome. But, once the various sequences that make up the genes have been carefully placed, for many of them their real function is still unknown. To find out what information is written about genes, we need to find ways to "work" them, for example by inserting them into the genome of animal fetuses and observing their effects. And so did the group of zoologist Andrew Pask, at the University of Melbourne, Australia, with a gene (called Col2a1) from a Tasmanian tiger (Thylacinus cynocephalus). The choice of the animal makes the research doubly important, since this ferocious carnivorous marsupial is extinct: the last specimen died in captivity in 1936. The DNA used for the study was taken from specimens kept in a museum.
TO KNOW OUR ANCESTORS
After "marking" the Col2a1 with a substance that, under certain conditions, emits blue light, the gene was inserted in mouse fetuses which, growing, showed how the foreign sequence helped the development of the cartilage in their skeleton. The Pask technique will now probably also be used by other scholars, who, having isolated DNA from mammoths and even from Neanderthals, will try to deduce information on some former inhabitants of our planet. The objective of bringing extinct animals back to life …
Tiger, or even wolf, from Tasmania, the thylacine was a carnivorous marsupial widespread especially in Australia, from where it disappeared thousands of years ago following the introduction of dingoes by the first colonizers of the continent, while in Tasmania it resisted until beginning of the last century. The Tasmanian tiger was finally officially declared extinct in 1986. The Thylacine Museum is a section of the naturalworlds.org site entirely dedicated to this animal: there are, among other things, a series of black and white movies of captive thylacines, up to the last known specimen, who died in 1936. A good video summary of these films is instead online on YouTube.