Featured Research

from universities, journals, and other organizations

How a fish can fry: Scientists uncover evolutionary clues behind electric fish

Date:
April 29, 2014
Source:
Molecular Biology and Evolution (Oxford University Press)
Summary:
Take a muscle cell, modify it over millions of years, and you end up with an exciting and literally shocking evolutionary result: the electric fish. The authors of a new study speculate that the down-regulation of the Scn4aa gene leads to quicker evolution and adaptation. Electric fish have evolved several times in varying levels of complexity. By emitting and sensing weak electrical signals, the fish have bypassed the usual means of communication, such as with sounds and visual signals, and go directly to electrical signals. This allows them to quietly "talk" to each other in the dark so that most predators can't eavesdrop.

Take a muscle cell, modify it over millions of years, and you end up with an exciting and literally shocking evolutionary result: the electric fish. Electric fish have evolved several times in varying levels of complexity. Two groups of electric fish, one in Africa (Mormyroids) and one in South America (Gymnotiforms), have independently evolved sophisticated communication systems using these cells. By emitting and sensing weak electrical signals, the fish have bypassed the usual means of communication, such as with sounds and visual signals, and go directly to electrical signals. This allows them to quietly "talk" to each other in the dark so that most predators can't eavesdrop. Both groups of fish are incredibly diverse; one species, the famous electric eel of South America, even evolved such strong and intense electric signals that it can electrocute its prey.

Related Articles


A gene that is particularly important for electric cells is the voltage-gated sodium channel. During an ancestral gene duplication event, the voltage-gated sodium channel of muscle, Scn4a, duplicated to Scn4aa and Scn4ab. This caused sodium ion channel genes to diversify and in parallel the same duplicate gene, Scn4aa, specialized for electric cells in Africa and South America while the other, Scn4ab, remained specialized for muscles. The regulated currents flow through the ion channels and generate electrical signals. In the advanced online publication of Molecular Biology and Evolution, authors Ammon Thompson et al., showed that the Scn4aa sodium channel gene may have an evolutionary bias over its twin to take part in novel cell types derived from muscle cells.

Evidence for their hypothesis was provided by RT-qPCR data of Scn4aa and Scn4ab from electric fish, which were compared with non-electric fish. They speculate that the down-regulation of the Scn4aa gene leads to quicker evolution and adaptation. Also, in an exciting discovery, they found this same Scn4aa gene expression pattern in a species of fish that uses sound to communicate, showing another extraordinary evolutionary adaption from the ancient gene duplication. The results provide a compelling hypothesis that gene duplications and gene 'expression drift' may be a more common evolutionary phenomenon in the development of new organ systems.

By peering into the evolutionary history of these genes we're starting to understand why the same gene plays a role in the repeated evolution of these unusual organs," said researcher Ammon Thompson.


Story Source:

The above story is based on materials provided by Molecular Biology and Evolution (Oxford University Press). Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Thompson, D. Vo, C. Comfort, H. H. Zakon. Expression Evolution Facilitated the Convergent Neofunctionalization of a Sodium Channel Gene. Molecular Biology and Evolution, 2014; DOI: 10.1093/molbev/msu145

Cite This Page:

Molecular Biology and Evolution (Oxford University Press). "How a fish can fry: Scientists uncover evolutionary clues behind electric fish." ScienceDaily. ScienceDaily, 29 April 2014. <www.sciencedaily.com/releases/2014/04/140429184844.htm>.
Molecular Biology and Evolution (Oxford University Press). (2014, April 29). How a fish can fry: Scientists uncover evolutionary clues behind electric fish. ScienceDaily. Retrieved March 6, 2015 from www.sciencedaily.com/releases/2014/04/140429184844.htm
Molecular Biology and Evolution (Oxford University Press). "How a fish can fry: Scientists uncover evolutionary clues behind electric fish." ScienceDaily. www.sciencedaily.com/releases/2014/04/140429184844.htm (accessed March 6, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, March 6, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Praying Mantis Looks Long Before It Leaps

Praying Mantis Looks Long Before It Leaps

Reuters - Innovations Video Online (Mar. 5, 2015) — Slowed-down footage of the leaps of praying mantises show the insect&apos;s extraordinary precision, say researchers. Video provided by Reuters
Powered by NewsLook.com
Octopus Grabs Camera and Turns It Around On Photographer

Octopus Grabs Camera and Turns It Around On Photographer

Buzz60 (Mar. 5, 2015) — A photographer got the shot of a lifetime, or rather an octopus did, when it grabbed the camera and turned it around to take an amazing picture of the photographer. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
Ringling Bros. Eliminating Elephant Acts

Ringling Bros. Eliminating Elephant Acts

AP (Mar. 5, 2015) — The Ringling Bros. and Barnum & Bailey Circus is ending its iconic elephant acts. The circus&apos; parent company, Feld Entertainment, told the AP exclusively that the acts will be phased out by 2018 over growing public concern about the animals. (March 5) Video provided by AP
Powered by NewsLook.com
Raw: Tourists Visit Rare Grey Whales in Mexico

Raw: Tourists Visit Rare Grey Whales in Mexico

AP (Mar. 4, 2015) — Once nearly extinct, grey whales now migrate in their thousands to Mexico&apos;s Vizcaino reserve in Baja California, in search of warmer waters to mate and give birth. Tourists flock to the reserve to see the whales, measuring up to 49 feet long. (March 4) 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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