Featured Research

from universities, journals, and other organizations

Early exposure to insecticides gives amphibians higher tolerance later

Date:
July 29, 2013
Source:
University of Pittsburgh
Summary:
Amphibians exposed to insecticides early in life -- even those not yet hatched -- have a higher tolerance to those same insecticides later in life, according to a recent study.

Amphibians exposed to insecticides early in life -- even those not yet hatched -- have a higher tolerance to those same insecticides later in life, according to a recent University of Pittsburgh study.

Published in Evolutionary Applications, the Pitt study found that wood frog populations residing farther from agricultural fields are not very tolerant to a particular type of insecticide, but they can become more tolerant with early exposure.

"This is the first study to show that tadpole tolerance to insecticides can be influenced by exposure to insecticides extremely early on in life -- in this case, as early as the embryonic stage," said study principal investigator Rick Relyea, Pitt professor of biological sciences within the Kenneth P. Dietrich School of Arts and Sciences and director of the University's Pymatuning Laboratory of Ecology.

"Amphibian populations are declining worldwide, and pesticides and insecticides are one hypothesized cause," said Jessica Hua, lead author of the paper and a PhD candidate studying biological sciences in Relyea's laboratory. "So this discovery has promising implications for the persistence of amphibian populations."

The Pitt team -- which also included Nathan Morehouse, Pitt assistant professor of biological sciences -- examined three potential factors that might allow larval wood frogs to have a high tolerance to the insecticide: the concentration of the initial insecticide exposure, the timing of the exposure, and the population's history of exposure. They chose to work with carbaryl, a popular household insecticide that also is used for malaria prevention.

The researchers conducted experiments with both embryos and hatchlings that were collected as newly laid eggs from four Pennsylvania ponds -- two near agricultural fields and two farther away. Both embryos and hatchlings from all four environs were first exposed to a low, nonlethal concentration of the insecticide. Later, they exposed the same individuals to a lethal concentration of the insecticide at the tadpole stage and measured the tadpoles' mortality rates over the course of several weeks.

Next, the team wanted to observe whether insecticide tolerance played a role in the frogs' acetylcholinesterase (AChE), a key enzyme in the nervous system of animals. Carbaryl is known to bind itself to this AChE enzyme in frogs, causing their nervous systems to slow. The Pitt team measured the concentration of total tadpole AChE in a sample of tadpole bodies, finding that low exposure levels of carbaryl stimulated the tadpoles to produce greater amounts of the enzyme -- making them more tolerant to the insecticide later in life.

The team is now examining whether exposure to an insecticide early in life can make amphibians more tolerant to other insecticides.

"In other words, we are asking if a tolerance to one insecticide can convey cross tolerance to other insecticides that affect the nervous system similarly," said Hua.

The paper, "Pesticide Tolerance in Amphibians: Induced Tolerance in Susceptible Populations, Constitutive Tolerance in Tolerant Populations," first appeared online in Evolutionary Applications. This work was funded by a National Science Foundation grant to Relyea and grants from the University of Pittsburgh's G. Murray McKinley Research Fund and Freshwater Science Endowment Fund to Hua.


Story Source:

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


Journal Reference:

  1. Jessica Hua, Nathan I. Morehouse, Rick Relyea. Pesticide tolerance in amphibians: induced tolerance in susceptible populations, constitutive tolerance in tolerant populations. Evolutionary Applications, 2013; DOI: 10.1111/eva.12083

Cite This Page:

University of Pittsburgh. "Early exposure to insecticides gives amphibians higher tolerance later." ScienceDaily. ScienceDaily, 29 July 2013. <www.sciencedaily.com/releases/2013/07/130729133124.htm>.
University of Pittsburgh. (2013, July 29). Early exposure to insecticides gives amphibians higher tolerance later. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2013/07/130729133124.htm
University of Pittsburgh. "Early exposure to insecticides gives amphibians higher tolerance later." ScienceDaily. www.sciencedaily.com/releases/2013/07/130729133124.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 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:
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