Navigation Links
A frog's life is food for thought

Starvation, malnutrition and re-feeding can have deadly consequences for humans and most animals but not Australia's green-striped burrowing frog.

PhD student Rebecca Cramp from The University of Queensland has found that unlike most animals, which can't digest food after long periods of starvation, the green-striped burrowing frog is able to absorb nutrients 40 percent more effectively after 3 months without food, than frogs that had eaten regularly.

"They can take massive meals equivalent to 50 percent of their body mass and maximise their digestive capability from the outset," Ms Cramp said.

Little is known about the effects of prolonged food deprivation on the gut of animals that go without food for long periods. Ms Cramp's study is helping explain why animals such as the green-striped burrowing frog are able to gorge themselves on huge meals without overwhelming their digestive system.

"Nothing was known about their digestive physiology when I first started this project and for an animal that can starve for up to four years it is really interesting when you relate that back to human starvation," she said.

"There is no way a human could last for four years without food."

Green-striped burrowing frogs spend upwards of 10 months of the year in underground burrows in a hibernation-like state known as aestivation. During this time they do not feed and survive on fat reserves.

The frogs return to the surface after heavy rain, sometimes for as little as a week - to find food and build up fat reserves.

During the study Ms Cramp and her supervisor Professor Craig Franklin from the School of Integrative Biology collected frogs from areas west of the Great Dividing Range, including Dalby and Goondiwindi.

They brought the frogs back to the laboratory where one group was kept in aestivation while the other group were not allowed to aestivate and were fed regularly.

"I compared the various aspects of their gut biology and physiology," she said.

"We put animals into aestivation and woke them up and fed them to find out how quickly they got everything going again."

Ms Cramp's results show that animals can maintain the functional capacity of the gut during aestivation despite significant energetic cost, allowing them to digest food as soon as they resurface from aestivation.

"Despite the marked decrease in absorptive surface area of the gut of aestivating frogs, they appear to actually increase their absorptive capacity during aestivation," she said.

"Within 36 hours of the ingestion of the first meal the gut had all but returned to its pre-aestivation state, and by the completion of digestion of the first meal the gut was operating on par with that of non-aestivating frogs," she said.

"This rate of rectification of gut morphology is virtually unparalleled with the small intestine having increased in mass by 450 percent within just 36 hours."

The results of Ms Cramp's study could have important implications for human survival.

"Human survivors of starvation can endure the horrific and often fatal effects of re-feeding after starvation, including massive diarrhoea and gastric ulcers," she said.

"Science still understands very little about why that occurs and what can be done about it."

Ms Cramp said scientists originally thought that during aestivation frogs would shut down all non-essential energy consuming processes. Her results contradict this theory.

"It was really interesting to us that they do not appear to shut down the functional aspect of their gut biology," she said.

"It is important that they are able to eat and digest from the first meal because they are only up for as little as a week at a time before they have to go back down again."

The results of the study were featured in a recent edition of Science magazine and form the basis of Ms Cramp's PhD study, from which she hopes to graduate in July.


Source:Research Australia

Related biology news :

1. Different microarray systems more alike than previously thought
2. Atmosphere may cleanse itself better than previously thought
3. Lifes origins were easier than was thought
4. Alleged 40,000-year-old human footprints in Mexico much, much older than thought
5. Deep-rooted plants have much greater impact on climate than experts thought
6. Avian flu transmission to humans may be higher than thought
7. The diversity of marine life in the Gulf of Maine region is much greater than previously thought
8. Memory loss affects more of the brain than previously thought
9. Brain works more chaotically than previously thought
10. Liver regeneration may be simpler than previously thought
11. Anthrax attack posed greater potential threat than thought
Post Your Comments:

(Date:11/17/2015)... Paris from 17 th until 19 th ... from 17 th until 19 th November 2015.   ... the first combined scanner in the world which scans both ... two different scanners were required: one for passports and one ... same surface. This innovation is an ideal solution for electronic ...
(Date:11/12/2015)... Nov. 12, 2015  A golden retriever that stayed ... dystrophy (DMD) has provided a new lead for treating ... the Broad Institute of MIT and Harvard and the ... . Cell, pinpoints a protective ... the disease,s effects. The Boston Children,s lab of ...
(Date:11/10/2015)... 2015 About signature verification ... to identify and verify the identity of an ... the secure and accurate method of authentication and ... individual because each individual,s signature is highly unique. ... dynamic signature of an individual is compared and ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Malaysia , Nov. 24, 2015  Asia-Pacific ... contract research organisation (CRO) market. The trend of ... in lower margins but higher volume share for ... capacity and scale, however, margins in the CRO ... Organisation (CRO) Market ( ), finds ...
(Date:11/24/2015)... ... November 24, 2015 , ... Copper is an essential ... bound to proteins, copper is also toxic to cells. With a $1.3 million ... (WPI) will conduct a systematic study of copper in the bacteria Pseudomonas aeruginosa ...
(Date:11/24/2015)... PHILADELPIA, PA (PRWEB) , ... November 24, 2015 , ... ... young entrepreneurs at competitive events in five states to develop and pitch their BIG ... student projects from each state are competing for votes to win the title of ...
(Date:11/24/2015)... QUEBEC CITY , Nov. 24, 2015 /PRNewswire/ ... (the "Company") announced today that the remaining 11,000 ... Common Share Purchase Warrants (the "Series B Warrants") ... agreement were exercised on November 23, 2015, which ... Common Shares.  After giving effect to the issuance ...
Breaking Biology Technology: