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 National Aeronautics and Space Administration funded the research.
Wendy Lawton | EurekAlert!
New manifestation of magnetic monopoles discovered
08.12.2017 | Institute of Science and Technology Austria
NASA's SuperTIGER balloon flies again to study heavy cosmic particles
07.12.2017 | NASA/Goddard Space Flight Center
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology