Worms, flies and humans... how we are related

Paris - Biologists on Wednesday said the genetic machinery of humans, fruit flies and roundworms was similar in many surprising ways, a discovery that could help basic research into disease.

A consortium of more than 200 scientists compared the genome of modern man with that of two creatures widely studied in the lab - the fruitfly (Drosophila melanogaster) and a tiny creature called roundworm (Caenorhabditis elegans).

Even though the three species are obviously different, evolution used "remarkably similar molecular toolkits" to shape them, the scientists said.

The three share many genes that code for proteins and much of the switchgear for turning these genes on and off, according to their papers published in the journal Nature.

"When we look at flies or worms, it is difficult to believe that humans have anything in common with them," said Mark Gerstein, a professor of biomedical informatics at Yale University.

"But now we believe we can see deep similarities in them that better help us interpret the human genome."

Over half of the genes associated with cancers and other inherited diseases in humans also exist in the genome of the fruitfly, said Sarah Elgin, a professor of biology at Washington University in St Louis, Missouri.

The discovery could be used to fine-tune research into so-called epigenetic therapy, she added.

Epigenes are switches which determine whether a gene is silent or functions. They are influenced by old age and environmental stress, such as exposure to tobacco smoke or alcohol.

Pharmaceutical companies are hugely interested in drugs that can "fix" malfunctioning epigenes - more than 78 epigenetic therapy drugs are being devised for cancer alone. Other big disease targets are diabetes and Alzheimer's.

Elgin said drug designers had to take care these novel therapies did not perturb epigenetic machinery across the human genetic code, inflicting a knock-on effect in a way similar to chemotherapy.

Testing theories on model organisms like the humble fruitfly first could be a big help, she said.