| hers Present Archaea Genome Sequence | | | | (TIGR) in just over a year. Researchers applied a |
| In a major scientific breakthrough, a team of | | | | whole-genome random approach, using both a |
| DOE-funded researchers reported in the August | | | | small-insert (2.5-kb average) plasmid library and a |
| 23 issue of Science (273, 1058-73) that they had | | | | larger-insert (16-kb average) lambda library. All |
| sequenced the first complete genome of a | | | | clones were sequenced from both ends, with the |
| microorganism that confirms the existence of the | | | | lambda library used to verify contigs built from |
| third major branch of life on earth. For the first | | | | assembled plasmid sequences. Data, including |
| time, researchers can trek boldly across | | | | double the number of genes and proteins |
| uncharted terrain to make large-scale comparisons | | | | previously known for Archaea, are available on |
| among the three domains of life at the genomic | | | | the Web. |
| level. Researchers from The Institute for Genomic | | | | Fulfilling a DOE Mandate |
| Research (TIGR); University of Illinois, Urbana | | | | DOE and its predecessor agencies have a long |
| (UIU); and Johns Hopkins University presented the | | | | history of support for genetic research growing |
| sequence for Methanococcus jannaschii, a | | | | out of their legislative mandate to understand the |
| member of the Archaea domain of life. The other | | | | health effects of nuclear energy and radiation and |
| two major life groups are prokaryotes (bacteria) | | | | the byproducts of other forms of energy |
| and the more complex eukaryotes, which include | | | | production. DOE funded the Archaea research as |
| plants, animals, and humans. | | | | part of its Microbial Genome Program (MGP), a |
| "This brings to closure the question of whether | | | | complementary project to the Human Genome |
| Archaea are separate and distinct life forms," said | | | | Program. MGP is headed by Jay Grimes of the |
| Craig Venter (TIGR). "In decoding the genetic | | | | DOE Office of Health and Environmental Research |
| structure of Archaea, we were astounded to find | | | | (darrell..gov). |
| that two-thirds of the genes do not look like | | | | Begun in 1994, MGP's goal is to sequence |
| anything we've ever seen in biology before." | | | | microorganisms of interest to DOE's energy and |
| According to the Science paper, only about 38% | | | | environmental cleanup programs. M. jannaschii is |
| of M. jannaschii genes match a gene with a | | | | the second genome completed in MGP. The first, |
| known cellular function already entered in | | | | M. genitalium, is a bacterium thought to be the |
| sequence databases. Comparisons also were | | | | simplest known self-replicating and free-living life |
| made with genes found in the genomes of the | | | | form. |
| other two complete microbial genomes sequenced | | | | With a genome of just 580 kb, it provides |
| by TIGR, those of Mycoplasma genitalium and | | | | researchers with a model for the minimum |
| Haemophilus influenzae. | | | | number of genes and protein products necessary |
| More extensive gene comparisons will help | | | | for independent existence. |
| scientists better understand the evolution of all | | | | MGP Research Providing Clues to Understanding |
| three branches of life. Early analysis points to a | | | | Genetics |
| closer shared evolutionary heritage for the | | | | Private companies, universities, and DOE |
| Archaea and eukaryotes. This is particularly | | | | laboratories are now sequencing an additional ten |
| evident in the genes controlling information | | | | microbial genomes for MGP, including that of the |
| processing: transcription, translation, and DNA | | | | most radiation-resistant life form ever found. This |
| replication. Features shared with bacteria include | | | | organism, Deinococcus radiodurans, was first |
| the lack of a nucleus and strongly similar metabolic | | | | discovered in spoiled beef thought to have been |
| genes. "We can look at the Archaea as the living | | | | sterilized by radiation. The microbe is potentially |
| fossils of our prokaryotic [bacterial] ancestors," | | | | useful for cleanup of radioactive wastes as well as |
| observed Carl Woese (UIU). | | | | for adding to the understanding of sensitive |
| Random Sequencing Strategy | | | | enzymes - responsible for monitoring and repairing |
| Sequencing of the 1.7-Mb M. jannaschii genome, | | | | damage to DNA caused by radiation and other |
| which consists of three distinct genetic elements, | | | | environmental agents. |
| was completed by a team led by Carol Bult | | | | |