New findings do not support a recent analysis of the rough draft of the human genome that suggests that bacterial genes have been laterally transferred into the human genome.
ROCKVILLE, MD -- Researchers at The Institute for Genomic Research (TIGR) have discovered a significant discrepancy in a section of the human genome paper, which was published in Nature (Feb. 15, 2001) by the International Human Genome Sequencing Consortium (IHGSC). Their findings will be published as part of the May 18 issue of the journal Science, online at the Science Express web site.
Steven L. Salzberg, Ph.D., Owen White, Ph.D., Jeremy Peterson, and Jonathan A. Eisen, Ph.D., report in "Microbial genes in the human genome: lateral transfer or gene loss?" on the results of a study conducted at TIGR that reexamined the claim made by the IHGSC that a significant number of bacterial genes were laterally transferred to the human genome. The original report identified a set of 223 proteins as having "significant similarity to proteins from bacteria, but no comparable similarity to proteins from yeast, worm, fly and mustard weed" Based on this evidence, the earlier study concluded that these genes were likely transferred directly from bacteria into an ancestral vertebrate species.
TIGR scientists reanalyzed the 31,780 genes that were the focus of the IHGSC report, and also analyzed the 26,544 genes reported in the human genome paper published in Science (Feb. 16, 2001). They compared these human genes to a larger sample of genes from other organisms, including thousands of genes from partially sequenced genomes. Conducting a more detailed analysis built a stronger case against the claim of lateral transfer: with each new piece of analysis, the number of genes found only in humans and bacteria grew smaller and smaller.
"Our results suggest that many of the shared genes were simply lost by other eukaryotes, with variations in different organisms' rates of evoluti
Contact: Sharon Dukes
The Institute for Genomic Research