Featured Research

from universities, journals, and other organizations

Newly discovered gene enables fish to 'disappear'

Date:
October 29, 2010
Source:
Vanderbilt University Medical Center
Summary:
Researchers have discovered a new member of a gene family that has powerful influences on pigmentation and the regulation of body weight. The new gene, an agouti family gene called agrp2, has been found exclusively in bony fish, including zebrafish, trout and salmon. The protein it encodes enables fish to change color dramatically to match their surroundings, the researchers report.

Like other bony fish, the peacock flounder can change the color and pattern of its skin to blend into the sea floor. Roger Cone, Ph.D., and colleagues have discovered a gene that enables this color change.
Credit: Photo by Jimmie Mack

Researchers led by Vanderbilt's Roger Cone, Ph.D., have discovered a new member of a gene family that has powerful influences on pigmentation and the regulation of body weight.

Related Articles


The gene is the third member of the agouti family. Two agouti genes have been identified previously in humans. One helps determine skin and hair color, and the other may play an important role in obesity and diabetes.

The new gene, called agrp2, has been found exclusively in bony fish, including zebrafish, trout and salmon. The protein it encodes enables fish to change color dramatically to match their surroundings, the researchers report this week in the early edition of the Proceedings of the National Academy of Sciences (PNAS).

"When my graduate student, Youngsup Song, discovered a third agouti protein in the fish pineal gland, an organ that regulates daily rhythms in response to light, we initially thought we had found the pathway that regulates hunger diurnally," said Cone, chair of the Department of Molecular Physiology & Biophysics and director of the Vanderbilt Institute for Obesity and Metabolism.

"That is the mechanism that makes you hungry during the day, but not at night," he continued. "However, Chao Zhang, a graduate student who followed up the study, ultimately discovered that this agouti protein … is involved in the rapid pigment changes that allow fish to adapt to their environment."

This phenomenon, called background adaptation, also has been observed in mammals. The coat of the arctic hare, for example, turns from brown in summer to white camouflage against the winter snow.

In contrast to mammals that have to grow a new coat to adapt to a changing environment, fish, amphibians and reptiles can change their skin color in a matter of minutes.

The first agouti gene, which produces the striped "agouti" pattern in many mammals, was discovered in 1993. The same year, Cone and his colleagues at Oregon Health Sciences University in Portland reported the discovery of the gene that encoded the melanocortin-1 receptor, a key player in the pigmentation story.

They demonstrated that the agouti protein prevented the melanocortin-1 receptor in melanocytes (pigment cells) in the skin from switching on production of black-brown pigment, and instead shifted the pigment to yellow-red hues.

The second agouti gene encodes agouti-related protein (AgRP), which blocks a melanocortin receptor in the brain. It prevents the melanocortin-4 receptor from inhibiting food intake, and thus stimulates eating.

In the current paper, Cone's group reports that the newly discovered protein, AgRP2, regulates expression of the prohormone genes pmch and pmchl, precursors to melanin-concentrating hormone, which has a pigment-lightening effect.

"Together, the versatile agouti proteins and melanocortin receptors are responsible for regulation of body weight, the banded patterns of mammalian coats, and even red hair in most people," Cone said. The current work shows that agouti proteins are also involved in the camouflage mechanisms used in thousands of fish species.

Cone, who came to Vanderbilt in 2008, has spent most of his career studying how the melanocortin receptors in the brain regulate body weight. He and his colleagues have published more than three dozen papers elucidating elements of this complex signaling system.

Zhang is the first author of the PNAS paper, a collaborative effort of scientists from the Salk Institute for Biological Sciences, the University of California at Santa Cruz, the University of Oregon, as well as Vanderbilt.

The study was supported by the National Institutes of Health and the Bristol-Myers Squibb Foundation.


Story Source:

The above story is based on materials provided by Vanderbilt University Medical Center. The original article was written by Bill Snyder. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Zhang, Y. Song, D. A. Thompson, M. A. Madonna, G. L. Millhauser, S. Toro, Z. Varga, M. Westerfield, J. Gamse, W. Chen, R. D. Cone. Inaugural Article: Pineal-specific agouti protein regulates teleost background adaptation. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1014941107

Cite This Page:

Vanderbilt University Medical Center. "Newly discovered gene enables fish to 'disappear'." ScienceDaily. ScienceDaily, 29 October 2010. <www.sciencedaily.com/releases/2010/10/101029132928.htm>.
Vanderbilt University Medical Center. (2010, October 29). Newly discovered gene enables fish to 'disappear'. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2010/10/101029132928.htm
Vanderbilt University Medical Center. "Newly discovered gene enables fish to 'disappear'." ScienceDaily. www.sciencedaily.com/releases/2010/10/101029132928.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) has the story. Video provided by Buzz60
Powered by NewsLook.com
Rover Finds More Clues About Possible Life On Mars

Rover Finds More Clues About Possible Life On Mars

Newsy (Dec. 17, 2014) NASA's Curiosity rover detected methane on Mars and organic compounds on the surface, but it doesn't quite prove there was life ... yet. Video provided by Newsy
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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