Featured Research

from universities, journals, and other organizations

Evolutionary surprise: Developmental 'scaffold' for vertebrate brain found in brainless marine worm

Date:
March 14, 2012
Source:
Marine Biological Laboratory
Summary:
Scientists report finding some of the genetic processes that regulate vertebrate brain development in the acorn worm, a brainless, burrowing marine invertebrate.

An adult acorn worm with its proboscis on the bottom right and tail on the top left.
Credit: A. Pani

The origin of the exquisitely complex vertebrate brain is somewhat mysterious. "In terms of evolution, it basically pops up out of nowhere. You don't see anything anatomically like it in other animals," says Ariel Pani, an investigator at the Marine Biological Laboratory (MBL) in Woods Hole and a graduate student at the University of Chicago.

Related Articles


But recently in the journal Nature, Pani and colleagues report finding some of the genetic processes that regulate vertebrate brain development in (of all places) the acorn worm, a brainless, burrowing marine invertebrate that they collected from Waquoit Bay in Falmouth, Mass.

The scientists were searching for ancestral evidence of three "signaling centers" in the vertebrate embryo that are major components of an "invisible scaffold that sets up the foundation of how the brain develops," Pani says. Diagnostic molecular features of these signaling centers are mostly missing in the sea squirts and the lancelets, the invertebrate chordates that are the closest evolutionary relatives of the vertebrates. This had suggested that these signaling centers are key innovations that arose de novo in the vertebrate lineage.

Yet, surprisingly, the scientists found highly similar signaling centers in the more distantly related acorn worm (Saccoglossus kowalevskii), a hemichordate. Acorn worm embryos lack nervous system structures comparable to vertebrate brains, and their lineages diverged from vertebrates more than 500 million years ago. Pani and colleagues found that, in the acorn worm, the signaling centers direct the formation of the embryonic body plan.

"What this means is the last (common) ancestor of the hemichordates and the vertebrates, even though it presumably did not have a vertebrate-like nervous system, had some very complex and vertebrate-like mechanisms for establishing its body plan," Pani says. "And one of the broad implications is that weird, squishy marine animals can be very informative in terms of understanding the evolution of vertebrate development and genetics in a way that you wouldn't expect."

But the sea squirt shouldn't worry: it has not been usurped by the acorn worm. "The lancelet and ascidians (sea squirts) will still be the first animals we will look at if we want to understand vertebrate evolution. But if we find differences, we now know it is important to look at anatomically divergent animals, where you wouldn't have previously expected to find compelling similarities," Pani says. "I think this principle applies broadly to understanding animal evolution."

The MBL, where more than 200 different types of marine animals are collected and maintained, has long been a center for comparative studies of evolution and development. "It is a valuable perspective that scientists can now implement in a pretty straightforward way," Pani says. "Because of the advances in gene sequencing and developmental techniques, a lot of researchers are now free to pick an animal in an interesting place (in the evolutionary tree) and pursue research on it at a speed that wasn't possible before. I think that is going to have a really big impact."

Christopher Lowe, Pani's Ph.D. advisor, has been working on hemichordates at MBL since 2002, in collaboration with the labs of John Gerhart, Marc Kirschner, Elena Casey, and Mark Terasaki. "The MBL has been a great place for us to work," Pani says. "There is a lot of expertise on the rearing and spawning of the animals, and we have had a ton of help from staff. Zeiss and Nikon have loaned us equipment at the MBL for years. It's just been a really unique and collaborative environment combining organismal knowledge with high-end technical facilities."


Story Source:

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


Journal Reference:

  1. Ariel M. Pani, Erin E. Mullarkey, Jochanan Aronowicz, Stavroula Assimacopoulos, Elizabeth A. Grove, Christopher J. Lowe. Ancient deuterostome origins of vertebrate brain signalling centres. Nature, 2012; 483 (7389): 289 DOI: 10.1038/nature10838

Cite This Page:

Marine Biological Laboratory. "Evolutionary surprise: Developmental 'scaffold' for vertebrate brain found in brainless marine worm." ScienceDaily. ScienceDaily, 14 March 2012. <www.sciencedaily.com/releases/2012/03/120314142843.htm>.
Marine Biological Laboratory. (2012, March 14). Evolutionary surprise: Developmental 'scaffold' for vertebrate brain found in brainless marine worm. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2012/03/120314142843.htm
Marine Biological Laboratory. "Evolutionary surprise: Developmental 'scaffold' for vertebrate brain found in brainless marine worm." ScienceDaily. www.sciencedaily.com/releases/2012/03/120314142843.htm (accessed October 26, 2014).

Share This



More Fossils & Ruins News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) — Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Fossil Treasures at Risk in Morocco Desert Town

Fossil Treasures at Risk in Morocco Desert Town

AFP (Oct. 23, 2014) — Hundreds of archeological jewels in and around the town of 30,000 people prompt geologists and archeologists to call the Erfoud area "the largest open air fossil museum in the world". Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Oldest Bone Ever Sequenced Shows Human/Neanderthal Mating

Oldest Bone Ever Sequenced Shows Human/Neanderthal Mating

Newsy (Oct. 23, 2014) — A 45,000-year-old thighbone is showing when humans and neanderthals may have first interbred and revealing details about our origins. Video provided by Newsy
Powered by NewsLook.com
Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Newsy (Oct. 23, 2014) — You've probably seen some weird-looking dinosaurs, but have you ever seen one this weird? It's worth a look. Video provided by Newsy
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