Navigation Links
Athletic frogs have faster-changing genomes
Date:4/12/2012

Durham, NC Physically fit frogs have faster-changing genomes, says a new study of poison frogs from Central and South America.

Stretches of DNA accumulate changes over time, but the rate at which those changes build up varies considerably between species, said author Juan C. Santos of the National Evolutionary Synthesis Center in Durham, North Carolina.

In the past, biologists trying to explain why some species have faster-changing genomes than others have focused on features such as body size, generation time, fecundity and lifespan. According to one theory, first proposed in the 1990s, species with higher resting metabolic rates are likely to accumulate DNA changes at a faster rate, especially among cold-blooded animals such as frogs, snakes, lizards and fishes. But subsequent studies failed to find support for the idea.

The problem with previous tests is that they based their measurements of metabolism on animals at rest, rather than during normal physical activity, Santos said.

"Animals rarely just sit there," Santos said. "If you go to the wild, you'll see animals hunting, reproducing, and running to avoid being eaten. The energetic cost of these activities is far beyond the minimum amount of energy an animal needs to function."

To test the idea, Santos scoured forests in Colombia, Ecuador, Venezuela, and Panama in search of poison frogs, subjecting nearly 500 frogs representing more than 50 species to a frog fitness test.

He had the frogs run in a rotating plastic tube resembling a hamster wheel, and measured their oxygen uptake after four minutes of exercise.

The friskiest frogs had aerobic capacities that were five times higher than the most sluggish species, and were able to run longer before they got tired.

"Physically fit species are more efficient at extracting oxygen from each breath and delivering it to working muscles," Santos said.

To estimate the rate at which each species' genome changed over time, he also reconstructed the poison frog family tree, using DNA sequences from fifteen frog genes.

When he estimated the number of mutations, or changes in the DNA, for each species over time, a clear pattern emerged athletic frogs tended to have faster-changing genomes.

Santos tested for other factors as well, such as body and clutch sizes, but athletic prowess was the only factor that was consistently correlated with the pace of evolution.

Why fit frogs have faster-changing genomes remains a mystery. One possibility has to do with harmful molecules called free radicals, which increase in the body as a byproduct of exercise.

During exercise, the circulatory system provides blood and oxygen to the tissues that are needed most the muscles at the expense of less active tissues, Santos explained.

When physical activity has stopped, the rush of blood and oxygen when circulation is restored to those tissues produces a burst of free radicals that can cause wear and tear on DNA, eventually causing genetic changes that if they affect the DNA of cells that make eggs or sperm can be passed to future generations.

Before you ditch your exercise routine, Santos offers some words of caution. The results don't debunk the benefits of regular physical exercise, which is known to reduce the risk of cancer, heart disease, and diabetes.

"What applies to cold-blooded animals such as poison frogs doesn't necessarily apply to warm-blooded animals such as humans," Santos said.

The findings appeared in the April 10th issue of Molecular Biology and Evolution.


'/>"/>

Contact: Robin Ann Smith
rsmith@nescent.org
919-668-4544
National Evolutionary Synthesis Center (NESCent)
Source:Eurekalert  

Related biology news :

1. Sustainability, college athletics dont always connect
2. L-arginine: Supplement tested on fit, athletic men shows no advantage
3. Optimal topdressing applications for athletic fields determined
4. Athletic girls more likely to have impaired bone structure if menstrual cycle stops
5. Heat acclimation benefits athletic performance
6. Compression clothing and athletic performance -- functional or fad?
7. Impact sensor provides athletic support
8. Study: Popular supplement quercetin does not enhance athletic performance
9. Seriously, were poisonous: Coloration is an honest signal of toxicity in poison frogs
10. Frogs use calls to find mates with matching chromosomes, University of Missouri researchers find
11. Picture book portrays a hoppy future for endangered frogs
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Athletic frogs have faster-changing genomes
(Date:3/1/2017)...  Aware, Inc. (NASDAQ: AWRE), a leading supplier of ... Moberg has resigned, effective March 3, 2017, as ... and Treasurer of Aware citing a desire to retire.  ... of the Board of Directors of Aware. ... and co-President, General Counsel has been named Chief Executive ...
(Date:2/27/2017)... , Feb. 27, 2017   Strategic Cyber Ventures ... it has led a $3.5 million investment in  Polarity ... Strategic Cyber Ventures is DC based and is led ... Hank Thomas . Ron Gula , also a ... also participated in this series A round of funding. ...
(Date:2/21/2017)... and PORTLAND, Ore. , Feb. 22, ... Avamere Family of Companies (Avamere Health Services, Infinity Rehab, ... six-month research study that will apply the power of ... senior living and health centers. By analyzing data streaming ... gain insights into physical and environmental conditions, and obtain ...
Breaking Biology News(10 mins):
(Date:3/23/2017)... ... March 23, 2017 , ... ... that exhibits both viscous and elastic characteristics when deformed, which is identical to ... properties to gently absorb compressive forces and return to its natural state along ...
(Date:3/23/2017)... DUBLIN , Mar 23, 2017 ... "Biorefinery Products: Global Markets" report to their offering. ... The ... from $466.6 Billion in 2016 at a CAGR of 8.9%, ... of energetic and non-energetic bioproducts into seven major product segments: ...
(Date:3/23/2017)... , March 23, 2017  SeraCare ... to global in vitro diagnostics manufacturers and ... the industry,s first multiplexed Inherited Cancer ... testing by next-generation sequencing (NGS). The Seraseqâ„¢ ... developed with input from industry experts to ...
(Date:3/23/2017)... MENLO PARK, Calif., March 23, 2017  BioPharmX ... developing products for the dermatology market, today reported ... Jan. 31, 2017, and will provide an update ... from the year. "We are pleased ... productive year for BioPharmX," said President Anja Krammer. ...
Breaking Biology Technology: