Mutant flies give a buzz to research
THE NEXT TIME you take a rolled up magazine to the pesky fly hovering over your over-ripe fruit platter at a beach barbecue this summer, pause. Appearances are deceptive. Farmers and fruit stall holders might loath the bug-eyed fly for its aggressive eating habits, but it is, in fact, one the most valuable organisms in biological research.
To geneticists, the fruit fly, or drosophila to give its scientific name, is strikingly similar to human beings, despite its six legs and two wings. Due to its interesting mutations and the speed of its lifecycle, the fruit fly that has long been the focus of research, providing scientists with important insights into human biology.
'More than 60 per cent of human disease genes are found in the fruit fly genome, including genes that cause Alzheimer's, Parkinson's and Huntingdon's disease, and various cancer-causing genes,' said Dr Edwin Chan Ho-yin, assistant professor of biochemistry at the Chinese University of Hong Kong (CUHK).
Drosophila, which means 'dew-lover', also behaves in similar ways to humans. It falls over if it has too much alcohol (although it has been proven to be able to survive on a diet of alcohol fumes) and naps in the afternoons if it skips on sleep. Geneticists have exploited it to research alcoholism and insomnia.
Chan has been a fruit fly aficionado since his undergraduate days at CUHK more than ten years ago, and his enthusiasm helped create the 'Fruit Fly - Drosophila' exhibition currently running in the Science News Centre at the Hong Kong Science Museum.
He organised the display - including a case of fruit flies to be observed under the microscope - with the help of 10 biochemistry and biotechnology students from the CUHK Laboratory of Drosophila Research, a lab established in 2002 to research degenerative diseases such as Alzheimer's and Parkinson's disease.
The team is currently looking at Hsp70, a suppressor gene identified by Chan in 1999. The gene has the potential to freeze the progress of degenerative conditions.
His team is also investigating the 'dribble gene', so-called by Chan because it weaves between cells and cytoplasm like a basketball player. Dribble helps generate ribosome, part of the cell where protein is synthesized. A third area under investigation is the efficacy of materials used in Chinese medicine.
Fruit flies shot to scientific fame when the chance discovery in 1911 of a white-eyed fly in the midst of normal red-eyed ones led American scientist Tho-mas Hunt Morgan to unravel the secrets of genetic inheritance. In 1933, he was awarded the Nobel Prize in Physiology and Medicine for establishing the chromosome theory of heredity.
Another group of fruit fly researchers won the same Nobel Prize 60 years later for contributing to the understanding of the genetic control of embryonic development. 'Morgan was using fruit flies to study evolution,' said Chan. 'They have a short gestation period, just 12 days, and only live for two weeks. This means we can culture thousands of flies very easily in a very short space of time. This allows us to study genetic mutations across several generations and get results very quickly.'
The fruit fly has buzzed in and out of the news on a regular basis. In 1997, researchers in America were surprised to find that a single gene in the fly controlled the entire mating process, from courtship serenade to copulation, and infestations of the insects often threaten to destroy millions of dollars worth of fruit. Fruit fly studies have also fuelled the debate over evolution. Commentators questioning the theory of evolution point out that no new species of fruit fly has emerged in 100 years of research, despite the number of mutations.
The exhibition at the Science News Centre is the museum's attempt to keep up with changes in the scientific world. 'There's always a danger our exhibitions will go out-of-date,' said chief curator Yip Chee-kuen. 'The public wants the latest information, the latest breakthroughs. The News Centre is one way to keep up-to-date,' he said.
The centre features four zones of interest. SciTech Profile focuses on socially significant research being conducted in local and overseas universities. Hot Talk is where visitors can learn about biological pacemakers, earthquake warning technology, the human genome project and the latest on stem cell research.
Science Window, meanwhile, plays video documentaries, such as a chilling clip about the kissing bug, whose potentially lethal bite causes widespread misery in Central and South America. Science Web allows visitors to surf recommended Web sites for more information before returning home or to school.
Visitors to the museum and the Web site choose the centre topics, which are proposed by scientists at local universities. Over the last year, the Hong Kong public has voted for nanotechnology, plant and fungal biotechnology, and computer techniques for analysing facial features. Each exhibition lasts three months. Fruit flies will feature until the end of September.
'We were very excited when the fruit fly was chosen,' said Yip, who has twenty years experience working for Hong Kong's museums and has been chief curator since 1998. 'It has a surprise factor because most people have no idea it is such an important scientific resource. Most people just kill them when they see them at the market.'
The science museum opened in 1991 and it consistently sees more visitors pass the turnstiles than any other museum in Hong Kong. Last year it attracted more than 850,000 visitors, just 71,000 of whom were children on school visits.
'What we're trying to do is popularise science,' said Yip. 'We select exhibitions that are stimulating, imaginative, and that make visitors think.'
Some visitors agree. Charles Wong Kin-chiu, a computer technician, on a date with his girlfriend to visit the museum, said: 'You learn more about science here than in school. In science lessons, you can't see much and you just watch demonstrations.' Yip says he is not sure what will be the next Science News Centre feature. 'It's up to the museum visitors.'
