Featured Research

from universities, journals, and other organizations

The Origin Of The Brain Lies In A Worm

Date:
April 22, 2007
Source:
European Molecular Biology Laboratory
Summary:
Researchers find that the vertebrate nervous system is probably much older than expected. The study suggests that the last common ancestor of vertebrates, insects and worms already had a centralised nervous system resembling that of vertebrates today.

Researchers Detlev Arendt, Alexandru Denes and Gáspár Jékely
Credit: Image courtesy of European Molecular Biology Laboratory

The rise of the central nervous system [CNS] in animal evolution has puzzled scientists for centuries. Vertebrates, insects and worms evolved from the same ancestor, but their CNSs are different and were thought to have evolved only after their lineages had split during evolution. Researchers from the European Molecular Biology Laboratory [EMBL] in Heidelberg now reveal that the vertebrate nervous system is probably much older than expected. The study, which is published in Cell, suggests that the last common ancestor of vertebrates, insects and worms already had a centralised nervous system resembling that of vertebrates today.

Related Articles


Many animals have evolved complex nervous systems throughout the course of evolution, but their architectures can differ substantially between species. While vertebrates have a CNS in the shape of a spinal cord running along their backs, insects and annelid worms like the earthworm have a rope-ladder-like chain of nerve cell clusters on their belly side. Other invertebrates on the other hand have their nerve cells distributed diffusely over their body. Yet, all these species descend from a common ancestor called Urbilateria. If this ancestor already possessed a nervous system, what it might have looked like and how it gave rise to the diversity of nervous systems seen in animals today is what Detlev Arendt and his group study at EMBL. To do so, they investigate the nervous system of a marine annelid worm called Platynereis dumerilii. "Platynereis can be considered a living fossil," says Arendt, "it still lives in the same environment as the last common ancestors used to and has preserved many ancestral features, including a prototype invertebrate CNS."

Arendt and his group investigated how the developing CNS in Platynereis embryos gets subdivided into the regions that later on give rise to the different CNS structures. The regions are defined by the unique combination of regulatory genes expressed, which endow every type of neuron with a specific molecular fingerprint. Comparing the molecular fingerpint of Platynereis nerve cells with what is known about vertebrates revealed surprising similarities.

"Our findings were overwhelming," says Alexandru Denes, who carried out the research in Arendt's lab. "The molecular anatomy of the developing CNS turned out to be virtually the same in vertebrates and Platynereis. Corresponding regions give rise to neuron types with similar molecular fingerprints and these neurons also go on to form the same neural structures in annelid worm and vertebrate."

"Such a complex arrangement could not have been invented twice throughout evolution, it must be the same system," adds Gáspár Jékely, a researcher from Arendt's lab, who contributed essentially to the study. "It looks like Platynereis and vertebrates have inherited the organisation of their CNS from their remote common ancestors."

The findings provide strong evidence for a theory that was first put forward by zoologist Anton Dohrn in 1875. It states that vertebrate and annelid CNS are of common descent and vertebrates have turned themselves upside down throughout the course of evolution.

"This explains perfectly why we find the same centralised CNS on the backside of vertebrates and the bellyside of Platynereis," Arendt says. "How the inversion occurred and how other invertebrates have modified the ancestral CNS throughout evolution are the next exciting questions for evolutionary biologists."

Article: A.S. Denes, G. Jékely, D. Arendt et al., Conserved mediolateral molecular architecture of the annelid trunk neuroectoderm reveals common ancestry of bilaterian nervous system centralisation, Cell, 20 April 2007


Story Source:

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


Cite This Page:

European Molecular Biology Laboratory. "The Origin Of The Brain Lies In A Worm." ScienceDaily. ScienceDaily, 22 April 2007. <www.sciencedaily.com/releases/2007/04/070420104758.htm>.
European Molecular Biology Laboratory. (2007, April 22). The Origin Of The Brain Lies In A Worm. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2007/04/070420104758.htm
European Molecular Biology Laboratory. "The Origin Of The Brain Lies In A Worm." ScienceDaily. www.sciencedaily.com/releases/2007/04/070420104758.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) — A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
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