The shape of life: research sheds light on how cells take shape

Aug 07, 2006

How life takes shape is a mystery. Butterfly or baby, cells organize themselves into tissues, tissues form organs, organs become organisms. Over and over, patterns emerge in all living creatures. Spiders get eight legs. Leopards get spots. Every nautilus is encased in an elegant spiral shell.

This phenomenon of pattern formation is critical in developmental biology. But the forces that govern it are far from clear. Alan Turing, father of modern computer science, suggested that the basis for pattern formation was chemical. New research conducted at Brown University and published in the Proceedings of the National Academy of Sciences supplies another surprising answer: Physical, as well as chemical, forces can dictate pattern formation.

In a two-year study, Brown physicists James Valles and Jay Tang puzzled over the patterns created by proteins called microtubules. Shaped like long, skinny straws, these proteins are puny – they measure only about 250 atoms wide – but play critical roles in the body. Microtubules help cells divide. They also act as scaffolds, giving cells their shape, and serve as train tracks of sorts, moving important bits like chromosomes and mitochondria around inside of cells.

As microtubules multiply, they form patterns that can be seen by the naked eye. The pattern is a series of waves that look a bit like zebra stripes. How, Valles and Tang asked, do they form?

Working with graduate students Yifeng Liu and Yongxing Guo, Valles and Tang grew their own microtubules then studied them under three types of microscopes. After two years of work, they solved the mystery. Chemical bonding and mechanical instability were responsible for the stripes.

In the first stage of the process, the microtubules line up uniformly, like pickets in a fence. As the microtubules continue to grow, they clump together in bundles of 200 to 300. Then these bundles buckle. Valles and Tang believe that the buckling occurs because, as microtubules grow, they create energy and generate force. Then the bundles buckle to relieve compression stress.

"Think of it like the 'wave' that fans create during a soccer game. One bundle buckles, then it sets off another bundle, then another bundle, until you get a sea of undulating stripes," Valles said. "What's exciting is that this finding may provide insight into how the shapes that make up the human body are created."

Tang agreed: "Pattern formation is critical to the creation of life. Now we really understand the mechanism behind this type of pattern in microtubules. Force is the key."

The paper is available online and in pdf format at www.pnas.org/cgi/content/full/103/28/10654

Source: Brown University

Explore further: Heat makes electrons spin in magnetic superconductors

Related Stories

Celestial fireworks celebrate Hubble's 25th anniversary

49 minutes ago

The glittering tapestry of young stars flaring to life in this new NASA/ESA Hubble Space Telescope image aptly resembles an exploding shell in a fireworks display. This vibrant image of the star cluster Westerlund ...

Improving accuracy in genome editing

52 minutes ago

Imagine a day when scientists are able to alter the DNA of organisms in the lab in the search for answers to a host of questions. Or imagine a day when doctors treat genetic disorders by administering drugs ...

Ultra-sensitive sensor detects individual electrons

54 minutes ago

A Spanish-led team of European researchers at the University of Cambridge has created an electronic device so accurate that it can detect the charge of a single electron in less than one microsecond. It has ...

Recommended for you

Heat makes electrons spin in magnetic superconductors

Apr 24, 2015

Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published yesterday in Physical Review Le ...

ICARUS neutrino experiment to move to Fermilab

Apr 23, 2015

A group of scientists led by Nobel laureate Carlo Rubbia will transport the world's largest liquid-argon neutrino detector across the Atlantic Ocean from CERN to its new home at the US Department of Energy's ...

National security on the move with high energy physics

Apr 23, 2015

Scientists are developing a portable technology that will safely and quickly detect nuclear material hidden within large objects such as shipping cargo containers or sealed waste drums. The researchers, led ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.