Monday, February 12, 2001 Home > Page One > Article News Page One National World Features/Arts Entertainment Column 8 Editorial Text Index -------------------------------------------------------------------------------- Sport Sports News SportsToday Rugby Heaven League HQ The Pavilion RealFooty -------------------------------------------------------------------------------- Biz/Tech Business News Biz.com Money Manager Trading Room I.T. News Icon -------------------------------------------------------------------------------- Extra Letters News Review Spectrum Travel -------------------------------------------------------------------------------- Sydney Weather TV Guide Visiting Weekends Away -------------------------------------------------------------------------------- Market Shopping Jobs Property Cars Auctions I.T. Jobs Classifieds -------------------------------------------------------------------------------- Services Advertise - print - online Delivery - paper - e-mail - handheld -------------------------------------------------------------------------------- Help Audio/video - PAGE ONE Human genes tally gives us just two flies' worth By Deborah Smith, Science writer It takes far fewer genes than thought to make a human - about 30,000, just twice as many as needed for a fly or a worm. As well, more than 200 of our genes have come directly from bacteria. These are the two main surprises in analyses of the human genome published this week by rival teams of scientists. Related story · History helps break the human genetic code -------------------------------------------------------------------------------- The researchers found that most of our genes are ancient. Those controlling basic functions, such as the way our cells work, evolved just once - in simple organisms like yeast and bacteria - and have remained relatively unchanged over millions of years. What sets us apart from the flies and worms is the complexity of our proteins. Our extra genes do not make lots of new kinds of proteins. Rather, they reshuffle the different bits of old proteins in novel ways, like making more complex new cars out of old parts. What also makes us human is our intricate mechanism for switching genes on and off at various stages of life. The publicly funded International Human Genome Sequencing Consortium, involving 20 global laboratories, has outlined its draft sequence and analysis in Nature, to be published on Thursday. It estimates that humans have 31,000 protein-making genes, of which it can list 22,000. Dr Craig Venter's company, Celera Genomics, will publish its findings on Friday in Science, identifying 26,500 genes and another 12,000 possibles. Earlier estimates had centred around 100,000 genes. Fruit flies have 13,000 genes, nematode worms have 18,000 and the cress plant has 26,000. Professor David Baltimore, a Nobel laureate of the California Institute of Technology, said the Nature paper had chilled him. "It is a seminal paper, launching the era of post-genomic science." He said the discovery that we have so few genes made it unlikely that a direct comparison of human and chimpanzee genomes would easily reveal the subtle changes that led to speech or abstract reasoning. The presence of bacterial genes in humans meant that organisms with genes from different species could arise naturally, not just by genetic engineering, Professor Baltimore said. Human DNA is made up of 3.2 billion "letters". The public team identified 1.4 million variations in single letters, known as single nucleotide polymorphisms. These are the key to understanding an individual's susceptibility to conditions such as heart disease and diabetes, and their mental and physical capabilities. [go to top] In this section One Nation's knockout blow How the woman in the party frock changed the ground rules Hobson's choice for Libs: Hanson or her revenge Next time, it could be John Howard Allure of One Nation pivotal for Qld voters Anderson's advisers take fall for roads fiasco Survey reveals BAS burden as PM relents Wahid visit on again Human genes tally gives us just two flies' worth -------------------------------------------------------------------------------- Site Guide | Archive | Feedback | Privacy Policy Copyright © 2001. All rights reserved.