Featured Research

from universities, journals, and other organizations

Worms Control Lifespan At High Temperatures

Date:
April 17, 2009
Source:
University of California - San Francisco
Summary:
The common research worm, C. elegans, is able to use heat-sensing nerve cells to not only regulate its response to hotter environments, but also to control the pace of its aging as a result of that heat, according to new research.

Magnified image of C. elegans worms moving in a liquid medium.
Credit: NASA

The common research worm, C. elegans, is able to use heat-sensing nerve cells to not only regulate its response to hotter environments, but also to control the pace of its aging as a result of that heat, according to new research at the University of California, San Francisco.

Related Articles


The new findings have turned upside down a widespread assumption about how cold-blooded animals respond to and regulate heat, the researchers say. The study is reported in the online early edition of the journal Current Biology.

Researchers have known for years that cold-blooded animals, or ectotherms, go through life more quickly at high temperatures than at low temperatures, according to UCSF Professor Cynthia Kenyon, PhD, who was senior researcher on the paper.

At temperatures of 25 degrees Celsius and above, worms move, eat and digest food faster, mature faster and age faster than their counterparts at a more normal 20 degrees. The common assumption, she said, is that the accelerated aging process at higher temperatures occurred passively, in much the same way that a chemical reaction speeds up at higher temperatures.

"We've shown it's not so simple," said Kenyon, a professor in the UCSF Department of Biochemistry and Biophysics and director of the Larry L. Hillblom Center for the Biology of Aging at UCSF. She is renowned for her ongoing research on C. elegans (Caenorhabditis elegans) and aging.

Humans and other warm-blooded animals have a mechanism that enables us to maintain a constant temperature as our environment heats up or cools. Kenyon said most textbooks explain that worms and other ectotherms cannot do that.

"It's true that worms don't regulate their body temperature, but they do regulate their response to high temperature, slowing down processes that would otherwise go much faster. In fact, they even use steroid hormones to do this, just as we do to regulate our temperature," she said, noting that this might have been a very early evolutionary link between cold- and warm-blooded animals.

C. elegans has been known to have thermosensory or heat-sensing neurons, which allow the worms to move towards temperatures they associate with food. If the "chemical reaction" theory were accurate, worms at a constant hotter temperature would age at the same fast rate, whether their thermosensory neurons perceived the heat or not.

The researchers found that when they either killed the heat-sensing neurons or deactivated the worm's genes that produce steroids, the worms had an even greater response to the heat, and as a result aged and died much faster than their counterparts with active neurons. The authors conclude that these heat-sensing neurons actually help the worm regulate its response to increasing heat.

The data suggest that these thermosensory neurons affect lifespan at warm temperature by changing the activity of a steroid signaling pathway, which in turn affects longevity, according to the paper. Specifically, the authors suggest that at high temperature, the worm's thermosensory neurons produce a signal that stimulates expression of the daf-9 gene, which produces a steroid hormone that extends lifespan.

The researchers propose that this thermosensory system allows C. elegans to reduce the effect that warm temperature would otherwise have on the processes that affect aging, which is something that warm-blooded animals do by controlling the temperature itself.

This system may allow the animal to maintain a more normal rate of aging even if the temperature rises, Kenyon said.

Previous research also has linked the rate of aging in mammals with temperature. If mice are tricked into thinking that they are in a hot climate, they lower their body temperature and live longer.

While similar steroid hormone pathways exist in humans, Kenyon stressed that, at least for now, this research is more relevant to our general understanding of biology than to any human biomedical connection.

"These findings probably won't result in a new cure for cancer or Alzheimer's," she said. "But they may force us to rewrite the section on cold-blooded animals in high school biology textbooks."

The lead investigator on the paper and sole other author was Seung-Jae Lee, who is now with the Department of Biological Science, School of Interdisciplinary Bioscience and Bioengineering, World Class University Information Technology Conversions Engineering Program, POSTECH, Korea.


Story Source:

The above story is based on materials provided by University of California - San Francisco. Note: Materials may be edited for content and length.


Journal Reference:

  1. Seung-Jae Lee, Cynthia Kenyon. Regulation of the Longevity Response to Temperature by Thermosensory Neurons in Caenorhabditis elegans. Current Biology, 2009; DOI: 10.1016/j.cub.2009.03.041

Cite This Page:

University of California - San Francisco. "Worms Control Lifespan At High Temperatures." ScienceDaily. ScienceDaily, 17 April 2009. <www.sciencedaily.com/releases/2009/04/090416144646.htm>.
University of California - San Francisco. (2009, April 17). Worms Control Lifespan At High Temperatures. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2009/04/090416144646.htm
University of California - San Francisco. "Worms Control Lifespan At High Temperatures." ScienceDaily. www.sciencedaily.com/releases/2009/04/090416144646.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) — Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) — Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) — One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) — Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. 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