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Bringing the human genome home to Africa
by Dr Valerie Corfield
University of Stellenbosch Medical Research Council Centre for Molecular and Cellular Biology, University of Stellenbosch Medical School,
South Africa
The Human Genome Project comes of age
The Human Genome Project (HGP), a massive 15-year undertaking to capture the total nucleotide sequence of the 24 different human chromosomes, was conceived in the United States in the late 1980s. It took its first official "baby" steps in 1990, but, since then, the child has grown into an international giant. Its adolescence has been anxiously nurtured by an international team of academic scientists, while entrepreneurial "talent scouts" have attempted to adopt it and to develop its commercial potential.
As befits its status, this prodigy has enjoyed not one, but two, coming-of-age parties. The first, on 26 June 2000, was attended by the then-president of the United States, Bill Clinton, as well as the British Prime Minister, Tony Blair. Furthermore, Dr Francis Collins, representing the academic parents, and Dr Craig Venter, the founder and managing director of the rival commercial company, Celera Genomics, kissed and made up in front of the bright lights and cameras for "appearance's sake".
"Science by press release"
In a move that has been described as "science by press release", the world was told that the first step of the HGP was essentially complete. Nearly 90% of the total human genetic sequence had been captured in draft form, and the academic consortium's data, at least, lay in publicly accessible databases. However, this preliminary announcement was really an attempt to patch up the bitter wrangles that had developed between the two main role players, the HGP and Celera, and to declare the race to finish the first draft of human genomic sequence an honourable draw.
The actual publication of the data was preceded by a second coming-of-age party, in the form of a press conference, on 12 February 2001. There it was announced that the academic consortium and Celera had completed about 94% of the draft sequence and would publish their findings within the coming week's editions of the leading British journal Nature and in the leading US competitive journal Science, respectively. The rumblings caused by these events have not yet subsided, for while the Nature data is freely accessible through the Web, Celera's comes with restrictions on its use. This has raised issues about Science's decision to publish under such circumstances and accusations that Celera's success has been built on "the shoulders of giants", in that it has always had access to the HGP public domain data, while the reverse has not been true.
Nevertheless, it has been the competition between the two main players that accelerated the race to the finish line and saw the completion of the first draft sequence far ahead of schedule. Undoubtedly, the deluge of raw data it contains will keep academics and commercial concerns busy for decades. However, this monumental achievement represents not the end, but the beginning, of our attempt to unravel the mysteries of "what maketh man". The implications of this research can be projected into the fundamental biology of all organisms, into evolution, medicine, agriculture, industrial processes, environmental biotechnology, forensics and more.
Size doesn't count, it's the way that you use it
One of the most dramatic and humbling predictions in the February releases in Nature and Science is that humans may only have 27 000 to 40 000 genes. In fact, we may only have a few hundred more than mice and maybe only twice as many as the tiny fruit fly that hovers over ripe bananas. Yet, less than one year ago, published gene predictions ranged as high as 153 478, while a gene sweepstakes allows anyone to place their bets on how many genes will have been identified by 2003
(www.ensembl.org/sweepstake.html).
Current thinking is that it is not the number of genes that humans possess that determines the species, but the subtle and ingenious ways in which they are processed. The next stage of the research is to devise surer ways to identify, catalogue and confirm the true number of genes present, by studying the products that they produce. It is the proteins that the genes encode which ultimately are responsible for the assembly and functioning of the organism.
Bringing the human genome home to Africa
Many independent lines of research support the theory that the origins of man lie in Africa and the latest data from the HGP lends further support to this notion, in that there is more sequence variation within people in Africa than outside. This suggests that it was a small group of related people of African origin that left this continent and populated the rest of the world.
Interestingly, the new sequence data further dispels the notion of race, and shows that humans are 99.99% the same, with there often being more variation within sub-population groups than between groups. Yet, this variation is of considerable interest, as it is likely to be the basis of individual susceptibility and resistance to disease.
Genome research in South Africa
Although South Africa has not played an official role in the HGP, many different research groups in this country have contributed results that form part of the complex layers of data imposed on the draft and polished versions of the human genome nucleotide sequence. Undoubtedly, this is also true for groups working in other research centres in Africa, and it must also be remembered that the Human Genome is not just about humans, several hundred other genomes, animal, plant and bacteria are also being catalogued and data-enriched (annotated) by interest groups worldwide.
Dr Corfield is actively engaged in genetics research. Enter here to read
about her "Personal Safaris into the Genome" 
Dr Corfield will be speaking at this year's Sasol Scifest.
To find out more on the human genome go to her talk: "Alone at home with
your own Genome", Sunday 1st April at 12h00.
Pictures on this page courtesy of the DOE Human Genome Program Web-site
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