Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How the Slime Mold Gets Organized

15.03.2011
Cells at the tip of the slime mold's fruiting body organize into an epithelial layer and secrete proteins as do some animals cells

The so-called cellular slime mold, a unicellular organism that may transition into a multicellular organism under stress, has just been found to have a tissue structure that was previously thought to exist only in more sophisticated animals.

What's more, two proteins that are needed by the slime mold to form this structure are similar to those that perform the same function in more sophistical animals.

Shortly after an animal embryo forms, it develops a single layer of cells that, shaped like a hollow ball, is empty at its center. Acting as a kind of "man behind the curtain" that directs these cells to organize into this hollow formation are several proteins that help each cell touch its neighbors but keep its top surface exposed to the formation's empty interior.

Even after animals grow beyond the embryo stage, the cells in many organs of their bodies maintain this type of hollow structure. These organs include those in the digestive tracts of animals, which feature a layer of cells, called epithelial cells, that face inward to form a hollow structure and are shaped asymmetrically to give organs their directionality. For example, the asymmetric epithelial cells of animal intestines face inward to form a hollow structure through which nutrients are absorbed. Likewise, the asymmetric epithelial cells of animal glands, such as salivary and endocrine glands, also face inward to form a hollow structure. But instead of absorbing substances as do the epithelial cells of animal intestines, these glandular epithelial cells secrete into their hollow structure substances that they produce.

With funding from the National Science Foundation, Daniel Dickinson, W. James Nelson and William Weis--all of Stanford University--took a careful look at the final, mature stage of slime mold development under a high-powered microscope. They report their results in the journal Science, March 11, 2011.

The slime mold spends most of its life as a single-celled organism, living in soil and preying on bacteria. However when food runs short, thousands of slime mold cells aggregate to form a mound. They then grow into a fruiting body--which is a stalk, a few millimeters tall, whose top peeks over the surface of the ground and holds spores. The researchers found that the organization and directionality of cells in this top part of the extending stalk are surprisingly similar to those of the epithelial cells of some organs of higher animals.

Dickinson and his colleagues also discovered that in order for the cells in the top of the slime mold's stalk to organize into an epithelium, they need analogues to two of the many proteins that are needed by animal cells to organize into an epithelium. Called alpha-catenin and beta-catenin, these slime mold analogues are genetically and biochemically similar to their animal versions. And when the researchers removed these analogues from the cells of slime molds, they lost their ability to organize correctly.

In addition to requiring proteins that are similar to those required by some animal epithelial tissues, the slime mold's epithelium tissue behaves similarly to the epithelial tissue of some animals--it is secretory. It secretes proteins that coat the stalk of the fruiting body and give it the rigidity it needs to send its spores out onto the ground in search of new food.

"We don't know whether the ancient ancestor of slime molds and animals was actually able to form an epithelium," says Dickinson, "but it must have had alpha-catenin and beta-catenin, and we suspect that these proteins had some role in organizing cells."

Media Contacts
Bruce Goldman, Stanford University (650) 725-2106 goldmanb@stanford.edu
Lily Whiteman, National Science Foundation (703) 292-8310 lwhitema@nsf.gov
Principal Investigators
Daniel Dickinson, Stanford University (650) 723-9788 ddickins@stanford.edu
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2010, its budget is about $6.9 billion. NSF funds reach all 50 states through grants to nearly 2,000 universities and institutions. Each year, NSF receives over 45,000 competitive requests for funding, and makes over 11,500 new funding awards. NSF also awards over $400 million in professional and service contracts yearly.

Lily Whiteman | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>