Featured Research

from universities, journals, and other organizations

Elusive prey: Selection pressures imposed by predator fungi have shaped escape behavior in microscopic worms

Date:
September 3, 2011
Source:
University of Massachusetts Medical School
Summary:
New research offers evidence that for the first time illuminates a biological and ecological path that links genes to molecule to neural circuit to behavior to environment.

Escape responses are some of the most studied behaviors by neurobiologists who want to understand how the brain processes sensory information. The ability to evade predators plays a vital role in the process of natural selection. Animals explore their environment to find food, find mates and locate new habitats, and have developed distinct escape responses to avoid predators, thereby increasing their chances for survival. Yet there are few examples that illustrate a complete understanding of the basic biological mechanisms of behavior with its ecological relevance.

New research by scientists at the University of Massachusetts Medical School (UMMS) published this week in Current Biology offers evidence that for the first time illuminates a biological and ecological path that links genes to molecule to neural circuit to behavior to environment. "We're studying how the nervous system generates behavior and translates sensory information into a coordinated motor output," said Mark Alkema, PhD, assistant professor of neurobiology at UMMS and lead author of the study. "For example, when you try to swat a fly, it has to coordinate its leg lift and wing flapping in order to escape being crushed. We believe that the small roundworm C. elegans does something similar in its own escape-response."

A gentle touch to the head of the C. elegans causes the microscopic nematode to cease normal exploratory head movements and quickly reverse direction. This response is one of the rare examples where the complete path from sensory neuron to coordinated motor output is understood by scientists. What wasn't known, however, is why C. elegans would suppress exploratory head movements when touched on the head but not when touched on the nose or tail. While the C. elegans is commonly grown in petri dishes in laboratories, its normal habitat is in the soil. Dr. Alkema and his colleagues at UMMS hypothesized that the nematode adapted this singular behavior in response to predacious fungi found in its natural environment that use constricting rings to trap its prey.

"Predacious fungi and soil nematodes have a long predator-prey relationship that goes back more than 100 million years," said Alkema. "Predacious fungi have developed very sophisticated strategies to catch and devour nematodes. The most ingenious of these fungi use constricting rings that ensnare the nematode when it passes through the ring. But in the evolutionary arms race between the two organisms, the nematodes have found a way to escape these fungal nooses."

Though the fungi's ensnaring rings react quickly once the trap is triggered, there is a small delay that occurs during which the worm can carefully backup and escape the trap. Alkema suspected the suppression of head movements in response to touch would increase the microscopic worm's chances to escape from the deadly fungal noose.

To test the contribution of the head suppression gene in this predator-prey interaction, Sean Maguire, a research assistant, and Chris Clark, a PhD student, in Alkema's lab, performed competition experiments between mutant and normal nematodes. "What we found was that worms that couldn't suppress their head movements were caught much more efficiently than worms that could," said Clark. "This indicates that suppression of head movements provide a selective advantage to surviving fungal encounters in the natural environment for nematodes."

"This study raises the intriguing possibility that maybe this behavior has evolved as a result of selective pressures imposed by predacious fungi as part of an evolutionary arms race," said Alkema. "There is wide variety of nematodes with different escape behaviors. Since we know the neurotransmitters and receptors that control this behavior in C. elegans, we can start to understand how the environment has shaped the evolution of their behavior."


Story Source:

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


Journal Reference:

  1. Sean M. Maguire, Christopher M. Clark, John Nunnari, Jennifer K. Pirri, Mark J. Alkema. The C. elegans Touch Response Facilitates Escape from Predacious Fungi. Current Biology, 28 July 2011 DOI: 10.1016/j.cub.2011.06.063

Cite This Page:

University of Massachusetts Medical School. "Elusive prey: Selection pressures imposed by predator fungi have shaped escape behavior in microscopic worms." ScienceDaily. ScienceDaily, 3 September 2011. <www.sciencedaily.com/releases/2011/07/110728144948.htm>.
University of Massachusetts Medical School. (2011, September 3). Elusive prey: Selection pressures imposed by predator fungi have shaped escape behavior in microscopic worms. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2011/07/110728144948.htm
University of Massachusetts Medical School. "Elusive prey: Selection pressures imposed by predator fungi have shaped escape behavior in microscopic worms." ScienceDaily. www.sciencedaily.com/releases/2011/07/110728144948.htm (accessed August 22, 2014).

Share This




More Plants & Animals News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) According to a new study, spiders that live in cities are bigger, fatter and multiply faster. 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:
from the past week

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