Comparing chimp and human DNA

October 12, 2006

Scientists look to the chimpanzee genome to better understand what is uniquely human about our own. One goal is to find DNA elements that show evidence of rapid evolution in the human lineage. In a new study, published online in the open-access journal PLoS Genetics, Katherine Pollard, at the UC Davis Genome Center, and colleagues at UC Santa Cruz led by David Haussler used comparative genomics to investigate the properties of a set of 202 carefully screened "highly accelerated regions" (HARs).

The authors searched for stretches of DNA that were highly conserved between chimpanzees, mice, and rats, comparing those sequences to the human genome sequence in order to unravel the evolutionary forces at work behind the human genome's fastest evolving regions.

Pollard explains that "most of the differences between chimps and humans are not in our proteins, but in how we use them." Only three HARs lie in genes that are likely to encode proteins. The rest do not appear to code for genes at all; instead, many HARs are located close to genes involved in growth and development. The most dramatically accelerated region, HAR1, appears to make a piece of RNA that may have a function in brain development.

"They're not in genes, but they're near genes that do some very important stuff," Pollard said. Typically, non-coding regions of DNA evolve more rapidly than regions carrying genes because there is no selective pressure to stop mutations from accumulating. However, the human-accelerated regions are highly conserved across the other groups of animals that the researchers examined, suggesting that they have important functions that stop them from varying too much.
-end-
This study was funded by the National Institutes of Health and the Howard Hughes Medical Institute.

Please mention the open-access journal PLoS Genetics (http://www.plosgenetics.org) as the source for this article. Thank you!

PLEASE ADD THIS LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.doi.org/10.1371/journal.pgen.0020168 (link will go live on October 13)

Citation: Pollard KS, Salama SR, King B, Kern AD, Dreszer T, et al. (2006) Forces shaping the fastest evolving regions in the human genome. PLoS Genet 2(10): e168.

PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plge-02-10-pollard.pdf

RELATED IMAGE FOR PRESS USE: http://www.plos.org/press/plge-02-10-pollard.jpg

Caption: The chimpanzee and human genomes are more than 98% identical, but there are a few short DNA sequences that have changed significantly in humans since the two species diverged about 5 million years ago (see Pollard et al., http://dx.doi.org/10.1371/journal.pgen.0020168). These 'Human Accelerated Regions' (HARs) provide clues into our evolution. (Photograph: Image by Owen Booth.)

All works published in PLoS Genetics are open access. Everything is immediately available without cost to anyone, anywhere--to read, download, redistribute, include in databases, and otherwise use--subject only to the condition that the original authorship is properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

PLOS

Related DNA Articles from Brightsurf:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.

Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.

Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.

Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.

Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.

DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.

A new spin on DNA
For decades, researchers have chased ways to study biological machines.

From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.

Read More: DNA News and DNA Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.