Europe South Asia Asia Pacific Americas Middle East Africa BBC Homepage World Service Education



Front Page

World

UK

UK Politics

Business

Sci/Tech

Health

Education

Sport

Entertainment

Talking Point

In Depth

On Air

Archive
Feedback
Low Graphics
Help

Monday, October 4, 1999 Published at 18:02 GMT 19:02 UK


Sci/Tech

Gene mappers near historic goal

Drosophila: Studied by thousands of biologists

By BBC News Online Science Editor Dr David Whitehouse

Gene mappers have announced that they have nearly finished decoding the genetic blueprint of the fruit fly. It is an important step that will also help scientists understand human genes.

Fruit flies or Drosophila are used extensively in biology. Thousands of scientists around the world use them to study genetics and developmental biology.

They are ideal organisms. They are easy to grow, not too small and live only two weeks. They are considered so important that the scientists who established their significance won a Nobel prize in 1995. Importantly, they share most of their genes with humans.

United States company Celera Genomics has announced that it has determined the genetic code of the fruit fly but still has to assemble the genes into the correct order.

'Shotgun' method

"Over 1.8 billion base pairs, letters of genetic code, were sequenced," the company said.

Remarkably the company said it only started the work on the tiny fly, known to scientists as Drosophila melanogaster, in May.


[ image: Drosophila chromosomes]
Drosophila chromosomes
To get the blueprint, Celera scientists have used a controversial "shotgun" method to map genes. Rival scientists say that technique can miss important bits of the sequence. But Celera says the method catches everything that matters.

"The completion of Drosophila will validate the effectiveness of Celera's whole genome shotgun approach in deciphering complex genomes," J. Craig Venter, president of the company, said.

"By comparison, the first genome of a free-living organism, the bacterium Haemophilus influenzae, consisting of two million letters of genetic code, took one year to complete, and other early genomes not using Celera's whole genome shotgun strategy took over a decade to complete," a statement from the company said.

There is still work to be done on the fruit fly, Venter points out, "What's done is the sequencing phase, akin to gathering all the pieces of a jigsaw puzzle. Now they have to put them together. We have to close the gaps."

More complex

It is estimated that the fruit fly will have anywhere between 12,000 and 20,000 genes - humans have between 80,000 and 100,000 genes. Until now, the most complex organism that has been sequenced is the flatworm, C. Elegans. Drosophila is a much more complex animal, having a central nervous system.

Although insects are clearly very different from humans, on a genetic level we have a great many things in common.

After sequencing Drosophila, Celera has said it will now turn its full attention to the human genome.

"On the Tuesday after Labour Day, we switched everything 100 percent to sequencing the human genome," said Venter.

"Between now and the end of the year we will have covered at least 70 percent of the human genome and by early spring, by February or March, we should have 90 percent of it covered."





Advanced options | Search tips




Back to top | BBC News Home | BBC Homepage | ©


Sci/Tech Contents


Relevant Stories

04 Oct 99 | Sci/Tech
Similarity in diversity

04 Oct 99 | Sci/Tech
'Working draft' of human genome by 2000

10 Dec 98 | Sci/Tech
Small worm makes history

10 Dec 98 | Sci/Tech
A great landmark in science

11 Nov 98 | Sci/Tech
Scientists complete typhus gene map





Internet Links


Celera Genomics Corp

Drosophila Virtual Library

Drosophila Interactive

Edward Lewis, Christiane Nüsslein-Volhard and Eric Wieschaus (Nobel Prize Winners)


The BBC is not responsible for the content of external internet sites.




In this section

World's smallest transistor

Scientists join forces to study Arctic ozone

Mathematicians crack big puzzle

From Business
The growing threat of internet fraud

Who watches the pilots?

From Health
Cold 'cure' comes one step closer