Navigation Links
Desert woodrats switch one dietary poison for another
Date:4/18/2009

As the U.S. Southwest grew warmer between 18,700 and 10,000 years ago, juniper trees vanished from what is now the Mojave Desert, robbing woodrats of their favorite food.

Now biologists have narrowed the hunt for detoxification genes that let the rodents eat the toxic creosote bushes that replaced junipers.

"It was either eat it or move out," says biologist Denise Dearing of the University of Utah, lead author of a paper detailing the results, published on-line on April 7, 2009, in the journal Molecular Ecology.

"This is an excellent example of research that bridges the fields of ecology and physiology," says Mary Chamberlin, acting deputy division director of the National Science Foundation (NSF)'s Division of Integrative Organismal Systems, which funded the research.

"It underscores the importance of studying organismal biology in order to understand how animals may or may not adapt to changes in their ecosystems."

During the study, eight woodrats were captured from each of two western regions: the Mojave Desert and the cooler Great Basin. Rats from both areas were fed rabbit chow mixed with either creosote or juniper.

The scientists then scanned the rodents' genetic blueprints to look for active genes known as "biotransformation genes" because they produce liver enzymes to detoxify the poisons in creosote and the less-toxic juniper.

"We found 24 genes in woodrats from the Mojave Desert that could be key in allowing them to consume leaves from creosote bushes," Dearing says. "The leaves are coated with a toxic resin that can comprise up to 24 percent of the dry weight of the plant."

She conducted the study because "we don't really know how herbivores can feed on toxic diets. If we can understand it, we may be able to learn how they will deal with climate change.

"For example, the toxins in creosote could respond to increases in atmospheric carbon dioxide," she says. "The plants may make more toxins under increased carbon dioxide conditions."

Even with detoxification genes, creosote bush is so toxic the woodrats can eat only so much. When they eat it exclusively, in winter, they lose weight. In spring, they gain weight when they also eat other plants.

Juniper is also toxic, but not as much as creosote bush.

Before creosote came to the Southwest from South America, woodrats ate juniper throughout what is now the Great Basin of Utah and Nevada and the Mojave Desert of southwestern Utah, southern Nevada and inland southeastern California.

But things changed as the last Ice Age waned.

As the glaciers receded, creosote bush invaded. The Southwestern deserts formed as the land became hotter and drier, and creosote bush replaced juniper trees in those areas.

Dearing says that as creosote invaded, some woodrats already had genes to let them eat creosote, or there was a mutation in existing detoxification genes that allowed for creosote consumption.

Over time, Mojave woodrats with those genes were more likely to survive on creosote, while those in the Great Basin stuck to juniper.


'/>"/>

Contact: Cheryl Dybas
cdybas@nsf.gov
703-292-7734
National Science Foundation
Source:Eurekalert  

Related biology news :

1. UNCCD recognizes importance of satellites for combating desertification
2. Tiny dust particles from Asian deserts common over western United States
3. Small desert beetle found to engineer ecosystems
4. Geology and biology meet in the history of US southwestern desert surface waters
5. Desert woodrats switch one dietary poison for another
6. Switching goals
7. Researchers find signal that switches on eye development -- could lead to eye in a dish
8. Researchers identify how to switch off cancer cell genes
9. Leading cause of death in preemies might be controlled by resetting a molecular switch
10. Why the switch stays on
11. Electronic switch opens doors in rheumatoid joints
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Desert woodrats switch one dietary poison for another
(Date:4/6/2017)... , April 6, 2017 ... RFID, ANPR, Document Readers, by End-Use (Transportation & Logistics, ... Facility, Oil, Gas & Fossil Generation Facility, Nuclear Power), ... Educational, Other) Are you looking for a ... sector? ...
(Date:4/5/2017)... LONDON , April 4, 2017 KEY ... is anticipated to expand at a CAGR of 25.76% ... neurodegenerative diseases is the primary factor for the growth ... full report: https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The ... of product, technology, application, and geography. The stem cell ...
(Date:3/30/2017)... LOS ANGELES , March 30, 2017  On ... Hack the Genome hackathon at ... This exciting two-day competition will focus on developing health ... experience. Hack the Genome is ... has been tremendous. The world,s largest companies in the ...
Breaking Biology News(10 mins):
(Date:5/24/2017)... -- As Ebola resurfaces in the Democratic Republic ... cases now reported, a new analysis of the Ebola gene ... between the 2014 and 2017 outbreaks of the disease.  ... which preceded the 2014 outbreak. An analysis of the latest ... in 2014-15, which again precedes the current outbreak in the ...
(Date:5/23/2017)... ... May 23, 2017 , ... ... cardiovascular cells for research and the development of cardiac regeneration therapies. The ... large numbers of cardiomyocytes (hPSC-CMs). Due to varying differentiation efficiencies, further enrichment ...
(Date:5/23/2017)... ... May 22, 2017 , ... A new ... San Diego, California, this August will feature high-level speakers on quantum devices, graphene ... SPIE Optics and Photonics, the largest multidisciplinary optical sciences meeting in North America, ...
(Date:5/23/2017)... PA. (PRWEB) , ... May 23, 2017 , ... ... Clinical Works as Vice President of Clinical Operations. She brings years of ... and Yaupon Therapeutics. From her professional foundation as a licensed occupational therapist, through ...
Breaking Biology Technology: