Featured Research

from universities, journals, and other organizations

Immunity In Social Amoeba Suggests Ancient Beginnings

Date:
August 8, 2007
Source:
Baylor College of Medicine
Summary:
Finding an immune system in the social amoeba (Dictyostelium discoideum) is not only surprising but it also may prove a clue as to what is necessary for an organism to become multicellular, according to a new article.

Finding an immune system in the social amoeba (Dictyostelium discoideum) is not only surprising but it also may prove a clue as to what is necessary for an organism to become multicellular, said the Baylor College of Medicine researcher who led the research that appears in the journal Science.

Dictyostelium discoideum usually exists as a single-celled organism. However, when stressed by starvation, the single cells band together to form a slug that can move. Eventually the slug changes to produce cells that perform specific functions -- spores and stalks. In this new report, Dr. Adam Kuspa, chair of biochemistry and molecular biology at BCM, and his colleagues describe a new kind of cell they dubbed a "sentinel" cell.

Sentinel cells circulate within the slug, engulfing invading bacteria and sequestering poisons or toxins, eventually eliminating these from the slug. These cells often operate through a particular mechanism in the cells controlled by a Toll/Interleukin-1 Receptor domain protein (TirA), Kuspa and his team found.

This signaling pathway or a very similar one is present in plants and animals, he said. Now it has been identified in amoeba. It has not been found in fungi.

"Amoeba have, in the last 10 years, become appreciated as one of the four main forms of life in the crown group of eukaryotic (multicellular) organisms -- plants, animals, fungi and amoeba," said Kuspa. "What allowed them to become multicellular?"

One way to estimate the characteristics of the organism that went before those that were multicellular is to look for characteristics that are present in two, three or all four of these main groups, he said.

"Those were likely present in the progenitor organism," said Kuspa. Because three of the four major groups of organisms have this pathway, "I argue that means that the progenitor of all multicellular organisms had this pathway. Since that organism was not likely multicellular, it must have used it as some kind of signaling to respond to bacteria in the environment."

Looking at it from another point of view, "it's possible that one of the properties of those (crown) organisms that allowed them to become multicellular was the ability to distinguish self from non-self -- the hallmark of an immune system," said Kuspa. "The speculation is that a requirement of multicellularity is that you develop systems to recognize pathogens and other non-self cells from yourself."

Kuspa sees two paths for future research in the area. One is to look for evidence of the same immune mechanism and protein in other kinds of amoeba. The other is to look at unicellular organisms to determine if they have this same kind of immune signaling pathway.

"If none of the early diverging organisms that never became multicellular developed this kind of signaling system, it would subtly strengthen our argument," he said.

Others who took part in this work include Drs. Guokai Chen and Olga Zhuchenko, both of BCM.

Funding for this work came from the National Institutes of Health.


Story Source:

The above story is based on materials provided by Baylor College of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Baylor College of Medicine. "Immunity In Social Amoeba Suggests Ancient Beginnings." ScienceDaily. ScienceDaily, 8 August 2007. <www.sciencedaily.com/releases/2007/08/070802182049.htm>.
Baylor College of Medicine. (2007, August 8). Immunity In Social Amoeba Suggests Ancient Beginnings. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2007/08/070802182049.htm
Baylor College of Medicine. "Immunity In Social Amoeba Suggests Ancient Beginnings." ScienceDaily. www.sciencedaily.com/releases/2007/08/070802182049.htm (accessed October 2, 2014).

Share This



More Plants & Animals News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Annual Dog Surfing Competition Draws California Crowds

Annual Dog Surfing Competition Draws California Crowds

AFP (Sep. 30, 2014) — The best canine surfers gathered for Huntington Beach's annual dog surfing competition, "Surf City, Surf Dog." Duration: 01:15 Video provided by AFP
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