Navigation Links
Mate or hibernate? That's the question worm pheromones answer
Date:7/24/2008

GAINESVILLE, Fla. If worms could talk, they might tell potential suitors, "I like the way you wriggle," complete with that telltale come slither look. But worms send their valentines via signals known as pheromones, a complex chemical code researchers are now cracking, according to a study published Wednesday (July 23) in the journal Nature.

Scientists from the University of Florida, Cornell University, the California Institute of Technology and the U.S. Department of Agriculture have discovered the first mating pheromone in one of science's most well-studied research subjects, the tiny worm Caenorhabditis elegans. But perhaps even more interesting is what the newly discovered pheromone also directs worms to do hibernate.

At lower levels, the pheromone signals the male C. elegans to mate with its partner. But when the worm population grows and the food supply dwindles, the chemical signal increases and the cue changes from mate to hibernate. This discovery could help researchers find ways to combat more harmful worms that destroy crops and provide clues for scientists studying similar parasite worms, said Arthur Edison, Ph.D., a UF associate professor of biochemistry and molecular biology in the College of Medicine and one of the study's senior authors.

"Even though it's the same compound, it affects different behaviors," said Fatma Kaplan, Ph.D., a postdoctoral associate in Edison's lab and one of the study's lead authors. "It's two different life traits converging."

In 2002, Cal Tech researcher Paul Sternberg, Ph.D., discovered that male C. elegans were attracted to a signal the opposite sex was sending out, but scientists weren't sure exactly what it was.

"C. elegans is one of the best-studied organisms on earth," Edison said. "The entire cell lineage of the animal is known from fertilized egg to adult animal. Every single cell division had been mapped out. But until now, its small-molecule signaling has been poorly understood. We wanted to understand how C. elegans talk to each other, basically."

About four out of every five animals on the planet is the same type of organism as C. elegans a nematode, said Edison. Although the C. elegans worm, which is about 1 millimeter in length, is harmless to humans, many nematodes destroy crops or act as parasites in humans and animals, such as the large human intestinal parasite Ascaris lumbricoides. Because it is easy to grow and manipulate in the laboratory, C. elegans is a model for understanding the basic biology of humans, animals and other worms that threaten human health.

C. elegans worms are either male or hermaphrodite meaning they feature both male and female reproductive organs and to pinpoint how they communicate, UF researchers and their collaborators isolated the chemicals the hermaphrodites secrete and tested them on male worms.

Initial tests proved the males were attracted to the secretions when the hermaphrodites were fertile. Using mass spectroscopy and nuclear magnetic resonance spectroscopy including a UF- and National High Magnetic Field Laboratory-developed NMR probe that allows researchers to test extremely small amounts researchers isolated the three chemicals in these secretions that are responsible for the mating signal.

When tested individually, the chemicals produced little to no response. But the chemicals strongly attracted male worms when they worked in synergy with each other, said Edison, who also serves as director of the McKnight Brain Institute's Advanced Magnetic Resonance Imaging and Spectroscopy facility and co-principal investigator of the National High Magnetic Field Laboratory.

But it was a chance collaboration with Cornell researcher Frank Schroeder, Ph.D., that led to the paper's biggest finding, Edison said. Schroeder had recently discovered what's known as a dauer pheromone. These chemicals signal worms to enter a hibernation phase when the food supply is low. Schroeder's hibernation pheromone and the UF-discovered mating pheromone were almost identical. Tests in worms revealed that mating pheromones also act as a dauer pheromones at high concentrations.

"It's like a bell-shaped curve," Edison said. "If (the pheromone level is) too low, it doesn't work. If you add more, you get a nice mating response. If it gets high, the mating response stops and they go into hibernation mode.

"It makes nice ecological sense that (one compound) could be doing both jobs," he added.

"But before this work, nobody in the whole history of C. elegans research had associated dauer formation with mating. Now these small molecules link the two behaviors."

Researchers have been trying to find C. elegans mating pheromones for a long time, said Piali Sengupta, Ph.D., a professor of biology at Brandeis University, who agreed that it makes sense that the mating pheromone has a dual role in causing hibernation.

"This opens up the field," Sengupta said. "This is just the beginning. There is going to be a lot more (research) coming out related to this."


'/>"/>

Contact: April Frawley Birdwell
afrawley@ufl.edu
352-273-5810
University of Florida
Source:Eurekalert

Related biology news :

1. National Science Foundation funds research addressing enduring questions of life
2. How to stop regaining weight? Thats the real question
3. Answer to troublesome question of why some genetic assoc. studies have failed replication attempts
4. A fossilized giant rhino bone questions the isolation of Anatolia, 25 million years ago
5. Simple screening questionnaire for kidney disease outperforms current clinical practice guidelines
6. Cold Spring Harbor Laboratory to play central role addressing key questions in plant biology
7. UA-led research team awarded $50 million to solve plant biologys grand challenge questions
8. Computer-based tool aids research, helps thwart questionable publication practices
9. Sticky questions tackled in gecko research
10. New research on structure of bones raises questions for treatment of osteoporosis
11. TAU scientists probe deep questions aboard EcoOceans environmental research ship
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2016)... YORK , Feb. 2, 2016 ... of the bioinformatic market by reviewing the recent ... enabled tools that drive the field forward. Includes ... to: Identify the challenges and opportunities that ... providers and software solution developers, as well as ...
(Date:2/2/2016)... Feb. 2, 2016  Based on its recent ... Sullivan recognizes US-based Intelligent Retinal Imaging Systems (IRIS) ... Award for New Product Innovation. IRIS, a prominent ... North America , is poised to set ... diabetic retinopathy market. The IRIS technology presents superior ...
(Date:1/28/2016)... Synaptics (NASDAQ: SYNA ), a leading developer of ... ended December 31, 2015. --> ... increased 2 percent compared to the comparable quarter last year to ... was $35.0 million, or $0.93 per diluted share. ... first quarter of fiscal 2016 grew 9 percent over the prior ...
Breaking Biology News(10 mins):
(Date:2/4/2016)... , February 4, 2016 - New FDA action ... - New FDA action date of July 22, ... July 22, 2016   - ... in the past decade indicated for the treatment of signs and symptoms of ... has the potential to be the only product approved in the U.S. in ...
(Date:2/4/2016)... -- Beike Biotechnology, the Shenzhen ... in late 2015 to mark their successful combined efforts ... --> --> The signing, ... Therapy" was hosted by the Shenzhen Cell Bank and ... Beike Biotechnology Co., Ltd. Shenzhen,s ...
(Date:2/4/2016)... 2016 ContraVir Pharmaceuticals, Inc. (NASDAQ: CTRV ... commercialization of targeted antiviral therapies, announced today that it ... to be held February 8-9, 2016, at the Waldorf ... Growth & Healthcare Conference, taking place in ... James Sapirstein , Chief Executive Officer of ContraVir, ...
(Date:2/4/2016)... 2016 Strasbourg, France , ... --> Strasbourg, France , to the US ... is pleased to announce that it acted as an advisor ... in Strasbourg, France , to the US ... --> Transgene (Euronext: TNG), a member of ...
Breaking Biology Technology: