Flies are first cloned insects

Canadian scientists have managed to clone fruit flies, an achievement that could help to improve the cloning process in other animals. Using current techniques, most clones die before birth, probably because their genetic information is not properly 'reprogrammed'. Experiments with fruit flies might reveal the genes that are important in this process, and lead to the identification of their counterparts in other species. As team leader Vett Lloyd told BBC News Online, 'that's pretty much the only reason why you want to do this', adding 'there are more than enough fruit flies in the world'.

The team, based at Dalhousie University in Halifax, Canada, used a variation of the method used to create Dolly the cloned sheep. They removed the genetic material from a fertilised egg, and replaced it with that from an embryo cell. It took the team about 800 attempts to produce five fly clones, the team reported in the journal Genetics. The scientists are now attempting to create clones using genetic material taken from adult fly body cells.

As well as flies and sheep, scientists have managed to clone, among others, rats, mice, cats, pigs, cows and horses, but in all species the success rate of the procedure is very low, and the rate of abnormalities seen is very high. These problems are thought to be due to a failure of the cloned embryo's genes to 'reprogramme' themselves so that they can control normal development. The Dalhousie team now plan to look for mutations that make some flies more 'clonable', and to identify genes crucial to the reprogramming process in other species.

Another study reported last week revealed that the immune systems of cloned pigs are not as efficient as the immune systems of normal pigs. Scientists at the University of Missouri gave a naturally occurring bacterial toxin to seven young cloned pigs and 11 genetically similar non-cloned pigs. The cloned pig's immune response did not match that of the non-cloned animals, confirming earlier studies which suggest that cloned animals are more likely to die from infections.