AURORA, Colo. (Jan. 14, 2010) – Showing how all organisms on Earth are related to each other has been a major goal of biologists since the time of Darwin.  The “Tree of Life” illustration is critical to understanding when and how key traits— like the ability to cause or transmit harmful diseases—evolved. Progress has been slow, because the methods available for analyzing genes are costly, labor intensive and error-prone.  Because of this, the goal of constructing a complete Tree of Life (1) for the millions of species on our planet has seemed practically out of reach.

Now researchers at the University of Colorado School of Medicine have shown how assembly of the Tree of Life can be greatly sped up. Writing in the Proceedings of the National Academy of Sciences of the USA, postdoctoral fellow Chris Todd Hittinger and Professor Mark Johnston and their collaborators at Vanderbilt University report their use of new and very high throughput DNA sequencing technologies to identify hundreds of genes from 10 different species of mosquitoes.  By comparing these genes they were able to determine the relationships of these mosquitoes, which are responsible for spreading malaria, yellow fever, and dengue hemorrhagic fever.  The researchers describe how application of their approach will bring a complete Tree of Life on our planet within reach.

“There are thousands of mosquito species and more than 2 million species on our planet.  Determining how they are all related is a massive undertaking, and we have provided a roadmap for how to achieve the dramatic cost and labor reductions that will be required to reach this important goal,” says Mark Johnston, chairman of the Department of Biochemistry & Molecular Genetics at the University of Colorado Denver, School of Medicine.

“We developed an experimental and computational approach that promises to greatly speed the process.  We employed state-of-the-art “next-generation” DNA sequencing technology to sample hundreds of genes from 10 mosquito species.  This tremendous quantity of data allowed us to accurately determine their evolutionary relationships with unprecedented efficiency and at such a low cost that it will soon bring Darwin’s dream of the Tree of Life within reach” added Hittinger.

(1) The concept of a tree of life as a many-branched tree illustrates how all life on earth is related.

Faculty at the University of Colorado Denver’s School of Medicine work to advance science and improve care. These faculty members include physicians, educators and scientists at University of Colorado Hospital, The Children’s Hospital, Denver Health, National Jewish Health, and the Denver Veterans Affairs Medical Center. Degrees offered by the UC Denver School of Medicine include doctor of medicine, doctor of physical therapy, and masters of physician assistant studies.  The School is located on the University of Colorado’s Anschutz Medical Campus, one of four campuses in the University of Colorado system. For additional news and information, please visit the UC Denver newsroom online.


Contact: Jackie Brinkman, 303-724-1525, [email protected]

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