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 April 17, 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 April 17, 2014).

Share This



More Plants & Animals News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com
Raw: Three Rare White Tiger Cubs Debut at Zoo

Raw: Three Rare White Tiger Cubs Debut at Zoo

AP (Apr. 16, 2014) The Buenos Aires Zoo debuted a trio of rare white Bengal tiger cubs on Wednesday. (April 16) 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