Featured Research

from universities, journals, and other organizations

Gene regulation differences between humans, chimpanzees very complex

Date:
October 17, 2013
Source:
University of Chicago Medical Center
Summary:
Changes in gene regulation have been used to study the evolutionary chasm that exists between humans and chimpanzees despite their largely identical DNA. However, scientists have discovered that mRNA expression levels, long considered a barometer for differences in gene regulation, often do not reflect differences in protein expression -- and, therefore, biological function -- between humans and chimpanzees.

The study raises questions over why mRNA expression levels differ between species if they do not necessarily cause protein differences. Although further study is needed, Gilad believes this study suggests that protein expression levels evolve under greater evolutionary constraint than mRNA levels, via a yet-uncharacterized compensation or buffering mechanism.
Credit: Kitch Bain / Fotolia

Changes in gene regulation have been used to study the evolutionary chasm that exists between humans and chimpanzees despite their largely identical DNA. However, scientists from the University of Chicago have discovered that mRNA expression levels, long considered a barometer for differences in gene regulation, often do not reflect differences in protein expression -- and, therefore, biological function -- between humans and chimpanzees. The work was published Oct. 17 in Science.

"We thought that we knew how to identify patterns of mRNA expression level differences between humans and chimpanzees that would be good candidates to be of functional importance," said Yoav Gilad, PhD, Professor of Human Genetics at the University of Chicago. "Now we see that even such mRNA patterns are not translated to the protein level. Which means that it is unlikely that they can affect a functional phenotypic difference."

For genes to be expressed, DNA must be transcribed into messenger RNA (mRNA), which then code for proteins, the biological building blocks and engines that drive cellular function. Although humans and chimpanzees share highly similar genomes, previous studies have shown that the species evolved major differences in mRNA expression levels. Many of these differences were thought to indicate areas of evolutionary divergence, thus pointing to genes important for human-specific traits.

To test this, Gilad, Jonathan Pritchard, PhD, currently at Stanford University, and their team, spearheaded by postdoctoral fellow Zia Khan, PhD, used high-resolution mass spectrometry to compare the expression levels of thousands of proteins with corresponding mRNA expression data in human and chimpanzee cell lines.

The team found 815 genes with differing mRNA expression levels but only 571 genes that differed in protein expression. In total, they identified an estimated 266 genes with mRNA differences that did not lead to changes in protein levels. They found similar results in rhesus macaque cell lines when compared to both chimpanzees and humans, confirming the trend.

"Some of these patterns of mRNA regulation have previously been thought of as evidence of natural selection for important genes in humans, but this can no longer be assumed," Gilad said.

The study raises questions over why mRNA expression levels differ between species if they do not necessarily cause protein differences. Although further study is needed, Gilad believes this study suggests that protein expression levels evolve under greater evolutionary constraint than mRNA levels, via a yet-uncharacterized compensation or buffering mechanism.

For now, research that uses mRNA expression levels as a measure of the functional importance of a gene requires reassessment, and not just in studies on evolution.

"We've gained insight into complex diseases by studying mRNA transcripts, but we also have a lot of gaping holes in our knowledge. Perhaps some of them are because of this disparity," Gilad said.


Story Source:

The above story is based on materials provided by University of Chicago Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zia Khan, Michael J. Ford, Darren A. Cusanovich, Amy Mitrano, Jonathan K. Pritchard, and Yoav Gilad. Primate Transcript and Protein Expression Levels Evolve under Compensatory Selection Pressures. Science, October 2013

Cite This Page:

University of Chicago Medical Center. "Gene regulation differences between humans, chimpanzees very complex." ScienceDaily. ScienceDaily, 17 October 2013. <www.sciencedaily.com/releases/2013/10/131017144632.htm>.
University of Chicago Medical Center. (2013, October 17). Gene regulation differences between humans, chimpanzees very complex. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2013/10/131017144632.htm
University of Chicago Medical Center. "Gene regulation differences between humans, chimpanzees very complex." ScienceDaily. www.sciencedaily.com/releases/2013/10/131017144632.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microneedle Patch Promises Painless Pricks

Microneedle Patch Promises Painless Pricks

Reuters - Innovations Video Online (Oct. 18, 2014) Researchers at The National University of Singapore have invented a new microneedle patch that could offer a faster and less painful delivery of drugs such as insulin and painkillers. Video provided by Reuters
Powered by NewsLook.com
Raw: Nurse Nina Pham Arrives in Maryland

Raw: Nurse Nina Pham Arrives in Maryland

AP (Oct. 17, 2014) The first nurse to be diagnosed with Ebola at a Dallas hospital walked down the stairs of an executive jet into an ambulance at an airport in Frederick, Maryland, on Thursday. Pham will be treated at the National Institutes of Health. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Raw: Cruise Ship Returns to US Over Ebola Fears

Raw: Cruise Ship Returns to US Over Ebola Fears

AP (Oct. 17, 2014) A Caribbean cruise ship carrying a Dallas health care worker who is being monitored for signs of the Ebola virus is heading back to Texas, US, after being refused permission to dock in Cozumel, Mexico. (Oct. 17) Video provided by AP
Powered by NewsLook.com
Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

AFP (Oct. 17, 2014) All four suspected Ebola cases admitted to hospitals in Spain on Thursday have tested negative for the deadly virus in a first round of tests, the government said Friday. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins