Featured Research

from universities, journals, and other organizations

Natural-born Divers And The Molecular Traces Of Evolution

Date:
June 30, 2009
Source:
Society for Experimental Biology
Summary:
When the ancestors of present marine mammals returned to the oceans, their physiology had to adapt radically. Scientists have been studying how myoglobin, the molecule responsible for delivering oxygen to the muscles during locomotion, has been modified in seals and whales to help them cope with the needs of a life at sea.

Harbor seal swimming.
Credit: iStockphoto/Andy Raatz

An aquatic lifestyle imposes serious demands for the organism, and this is true even for the tiniest molecules that form our body. When the ancestors of present marine mammals initiated their return to the oceans, their physiology had to adapt radically to the new medium. Dr. Michael Berenbrink and his colleagues at Liverpool University have been studying how myoglobin, the molecule responsible for delivering oxygen to the muscles during locomotion, has been modified in seals and whales to help them cope with the needs of a life at sea.

The researchers have found evidence indicating that the net positive charge of this protein is increased in marine mammals compared with terrestrial relatives, and they have speculated that this may help improving the solubility of the molecule. This is important as divers may contain 10 times more myoglobin in their muscles than terrestrial animals. The team has also found a conspicuous increase of the amino acid histidine in the myoglobin of strong divers, which may allow the animal to deal better with the accumulation of lactic acid that is frequent during long dives (the same build up is the cause of the cramps we sometimes get during strenuous exercise).

In order to confirm that this was indeed the result of evolutionary pressure, they went on to study the molecular sequence of myoglobin in small aquatic mammals such as beavers, muskrats and water shrews, which only dive for considerably shorter periods of time, to see if they could also find evidence for the same trend. Indeed, the net charge of the myoglobin molecule in aquatic rodents was twice as high compared to their strictly terrestrial relatives, and the trend was also verified for some semi-aquatic species of insectivores. Graduate student Scott Mirceta will be presenting these latest results at the Society of Experimental Biology Annual Meeting in Glasgow on June 29, 2009.

The net electric charge of any protein is directly related to the charge of its individual amino acids, and therefore it can be predicted if the amino acid sequence is known. Dr. Berenbrink's team have determined large parts of the myoglobin sequence for four different species of insectivores, and combined it with the analysis of already published sequences from other species to reach their conclusions. They were careful to select species with close terrestrial relatives that could be used as a natural control group during the sequence comparison, so that differences at the molecular level could be safely assumed to be the product of their habitat preference. "This work will contribute to our understanding of protein solubility in general", explains Dr.Berenbrink. "It will also allow the analysis of natural selection on protein structure/function in multiple parallel cases in which a high muscle myogobin content evolved, such as in divers but also in burrowing animals that normally experience hypoxia."


Story Source:

The above story is based on materials provided by Society for Experimental Biology. Note: Materials may be edited for content and length.


Cite This Page:

Society for Experimental Biology. "Natural-born Divers And The Molecular Traces Of Evolution." ScienceDaily. ScienceDaily, 30 June 2009. <www.sciencedaily.com/releases/2009/06/090629081131.htm>.
Society for Experimental Biology. (2009, June 30). Natural-born Divers And The Molecular Traces Of Evolution. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2009/06/090629081131.htm
Society for Experimental Biology. "Natural-born Divers And The Molecular Traces Of Evolution." ScienceDaily. www.sciencedaily.com/releases/2009/06/090629081131.htm (accessed August 21, 2014).

Share This




More Plants & Animals News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) — According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com
Ramen Health Risks: The Dark Side of the Noodle

Ramen Health Risks: The Dark Side of the Noodle

AP (Aug. 21, 2014) — South Koreans eat more instant ramen noodles per capita than anywhere else in the world. But American researchers say eating too much may increase the risk of diabetes, heart disease and stroke. (Aug. 21) Video provided by AP
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