Of Jaws and Man
Initial decoding of elephant shark genome helps uncover ancient DNA in human genome
SINGAPORE AND ROCKVILLE, MD, December 21, 2006 — A joint team of scientists from Singapore A*STAR's Institute of Molecular and Cell Biology (IMCB) and the United States-based J. Craig Venter Institute have completed an initial sequence of the elephant shark genome. By comparing this genome to the human genome they have discovered a large number of ancient DNA fragments in the human genome.
These ancient DNA fragments in the human genome do not make proteins; instead they regulate genes that make proteins involved in human development and physiology. Disruption in the regulation of these genes can lead to the development of many human diseases. The findings, published in the latest issue (22 nd December 2006) of the journal, Science, should help to better understand how human genes are regulated and the molecular basis of diseases.
A major challenge for researchers after the publication of the human genome sequence in 2001 has been the identification of elements that regulate the expression of genes. Unlike genes, regulatory elements do not have well-defined structures. While genes make up 1.5% of the human genome, regulatory elements account for 4% of the remaining noncoding sequences. Comparison between human and other genomes is known to be an effective approach for identifying regulatory elements.
The present findings are particularly significant because comparison with genome sequences of pufferfish and zebrafish, which are more closely related to humans than elephant shark (a member of the oldest living group of jawed vertebrates known as cartilaginous fishes'), have identified less than half of these human elements. These results highlight the importance of the elephant shark as a reference vertebrate genome for understanding the human genome.
The elephant shark, also known as the elephant fish or ghost shark, is native to the waters off New Zealand and Southern Australia. In the present study, sequences covering about 75% of the elephant shark genome were generated and compared with the human genome.
Associate Professor B. Venkatesh, a Principal Investigator at IMCB commented, "Although it was predicted that the elephant shark genome would provide valuable insights to the human genome, discovery of such a large number of potential regulatory elements was unexpected. We hope to learn much more about the human genome and the evolution of vertebrates when the additional genome sequence of the elephant shark is completed."
"This research, like our previous initial sequencing of the dog genome, shows the value of rapid, lower coverage whole genome shotgun sequencing to identify important characteristics of model organisms. This first analysis of elephant shark confirms our suspicions that it is a very important vertebrate that will lead to better understanding of humans and human disease," said Ewen Kirkness, Ph.D., lead researcher on the project from the J. Craig Venter Institute.
Prof. Sir David Lane , Executive Director, IMCB added: " I am delighted by this latest contribution from our genomics team. It is amazing how quickly the elephant shark genome has been analyzed and confirmed our hopes that it would represent another key genome. It will contribute greatly to our efforts to understand how genes are controlled in man. In some ways we may be closer to the shark than we thought."
About the Institute of Molecular and Cell Biology (IMCB)
http://www.imcb.a-star.edu.sg
The Institute of Molecular and Cell Biology (IMCB) is a member of Singapore's Agency for Science, Technology and Research (A*STAR) and is funded through A*STAR's Biomedical Research Council (BMRC). It is a world-class research institute in biomedical sciences with core strengths in cell cycle, cell signaling, cell death, cell motility, protein trafficking, developmental biology, structural biology, genomics and infectious diseases. Its achievements include leading an international consortium that successfully sequenced the pufferfish (Fugu) genome. The IMCB was awarded the Nikkei Prize 2000 for Technological Innovation in recognition of its growth into a leading international research centre and its collaboration with industry and research institutes worldwide. Established in 1987, the Institute currently has 40 independent research groups with more than 400 staff members.
About J. Craig Venter Institute
http://www.venterinstitute.org
The J. Craig Venter Institute (JCVI) is a not-for-profit research institute dedicated to the advancement of the science of genomics; the understanding of its implications for society; and the communication of those results to the scientific community, the public, and policymakers. Founded by J. Craig Venter, Ph.D., the Institute, through its two divisions — The Institute for Genomic Research (TIGR) and The Center for the Advancement of Genomics (TCAG) is home to more than 500 scientists and staff with expertise in human and evolutionary biology, genetics, bioinformatics/informatics, high-throughput DNA sequencing, information technology, functional genomics, and genomic and environmental policy research.
# # #
For more information, please contact:
Joshua WOO
Corporate Communications
Institute of Molecular and Cell Biology
Tel: 65-65869771
Email: woohk@imcb.a-star.edu.sg
Heather KOWALSKI
Kowalski Communications
J. Craig Venter Institute
Tel: 202-294-9206
Email: hkowalski@kowalskicommunications.com
# # #