NEW YORK, Aug. 24 – Researchers at two California-based labs contested the widely cited size of the human genome, suggesting in a letter to a scientific journal on Friday that the actual number of human genes may be significantly greater than the estimated 30,000 sequenced and published by Celera Genomics and the Human Genome Project.
Writing in a letter to the editor of Cell , scientists led by Michael Cooke and John Bogenesch at the Genomics Institute of the Novartis Research Foundation together with researchers at the Scripps Research Institute said that a comparison of the two published versions of the human genome illustrated the little known fact that they have only 15,000 genes in common. Thus, if the two teams of researchers each accurately identified an additional 10,000-15,000 genes, the total number of genes should equal at least 40,000.
The discrepancy highlights the uncertainty inherent in the computer models used to find the locations of genes in the human genome, as well as the limits of scientists’ understanding of the human genome itself.
Before the Human Genome Project, many scientists assumed that the complexity of human life could be explained only by the existence of at least 100,000 human genes. Even today, many scientists insist the total number must be greater than 30,000.
The letter in Cell , however, did not address the accuracy of the existing total. If both teams have predicted genes to exist where they do not, the total number may still not exceed the 30,000 estimate.
It was not immediately clear what methods the authors of the letter used to arrive at their conclusion, or whether they intend to publish their findings.