Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Back to basics: Scientists discover a fundamental mechanism for cell organization

26.05.2009
Scientists have discovered that cells use a very simple phase transition -- similar to water vapor condensing into dew -- to assemble and localize subcellular structures that are involved in formation of the embryo.

The discovery, which was made during the 2008 Physiology course at the Marine Biological Laboratory (MBL), is reported in the May 21 early online edition of Science by Clifford P. Brangwynne and Anthony A. Hyman of the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden, Germany, and their colleagues, including Frank Jülicher of the Max Planck Institute for the Physics of Complex Systems, also in Dresden.

Working with the worm C. elegans, the scientists found that subcellular structures called P granules, which are thought to specify the "germ cells" that ultimately give rise to sperm or eggs, are liquid droplets that transition between a dissolved or condensed state. In newly fertilized one-cell embryos, the P granules are dissolving throughout the cell, like water droplets at high temperature. But prior to the first cell division, the P granules rapidly condense at one end of the cell, as if the temperature were suddenly lowered there. The progenitor germ cell subsequently forms where the P granules have condensed.

"This kind of phase transition could potentially be working for many other subcellular structures similar to P granules," Brangwynne says. P granules are ribonucleoprotein assemblies (RNPs), and a given cell may contain dozens of different types of RNPs.

"It is interesting to think about this in the context of evolution and the origin of life," he says. "What we have found is that, in some cases, simple physical-chemical mechanisms, such as a classic phase transition, give rise to subcellular structure…This is likely the kind of thing that happened in the so-called primordial soup; but it's not surprising that even highly evolved cells continue to take advantage of such mechanisms."

The insight emerged when Brangwynne, a biophysicist who was a teaching assistant in the MBL Physiology course, watched a movie of P granules fusing that had been made by a student in the course, David Courson of the University of Chicago. "We were looking at that and thinking, man, that looks exactly like two liquid droplets fusing," Brangwynne says. They began making measurements of liquid-type behaviors in P granules, and made the first estimates of P granule viscosity and surface tension. By the end of the course they were "90 percent sure" that P granules are liquid droplets that localize in the cell by controlled dissolution and condensation, a concept that Brangwynne further confirmed after he returned to Dresden.

Brangwynne credits the discovery to the "dynamic nature" of the MBL Physiology course, where scientists from different fields (biology, physics, computer science) work intensively together on major research questions in cell biology. In addition to Courson, the other co-authors of the Science paper who were in the Physiology course are Hyman, and Jülicher, who were Physiology faculty members, and Jöbin Gharakhani, who was a teaching assistant. The paper also credits Physiology course co-director Tim Mitchison for valuable discussions.

"There are so many molecules in the cell, and we are coming out of the age of cataloguing them all, which was critical, to find out who the players are," Brangwynne says. "Now we are putting it all together. What are the principles that come out of these complex interactions (between molecules)? In the end, it may be relatively simple principles that help us understand what is really happening."

Citation:

Brangwynne, C.P., Eckmann, C.R., Courson, D.S., Rybarska, A., Hoege, C., Gharakhani, J., Jülicher, F., and Hyman, A.A. (2009) Germline P Granules are Liquid Droplets that Localize by Controlled Dissolution/Condensation. Early publication online by the journal Science, at the Science Express web site: http://www.sciencexpress.org.

The MBL is a leading international, independent, nonprofit institution dedicated to discovery and to improving the human condition through creative research and education in the biological, biomedical and environmental sciences. Founded in 1888 as the Marine Biological Laboratory, the MBL is the oldest private marine laboratory in the Americas.

Diana Kenney | EurekAlert!
Further information:
http://www.mbl.edu

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

A CLOUD of possibilities: Finding new therapies by combining drugs

24.05.2017 | Life Sciences

Carcinogenic soot particles from GDI engines

24.05.2017 | Life Sciences

A quantum walk of photons

24.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>