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 A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

On the way to developing a new active ingredient against chronic infections

21.08.2017 | Life Sciences

Smart Computers

21.08.2017 | Information Technology

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>