In a new study from the University of Pennsylvania and National Institute of Dental and Craniofacial Research, scientists used an innovative technique to study how cells move in a three-dimensional matrix, similar to the structure of certain tissues, such as the skin. They discovered an entirely new type of cell movement whereby the nucleus helps propel cells through the matrix like a piston in an engine, generating pressure that thrusts the cell’s plasma membrane forward.
"Our work elucidated a highly intriguing question: how cells move when they are in the complex and physiologically relevant environment of a 3-D extracellular matrix," said Hyun (Michel) Koo, a professor in the Department of Orthodontics at Penn’s School of Dental Medicine. "We discovered that the nucleus can act as a piston that physically compartmentalizes the cell cytoplasm and increases the hydrostatic pressure driving the cell motility within a 3-D matrix."
R. J. Petrie, H. Koo, K. M. Yamada. Generation of compartmentalized pressure by a nuclear piston governs cell motility in a 3D matrix. Science, 2014; 345 (6200): 1062 DOI: 10.1126/science.1256965
Penn and NIH researchers measured the internal pressure of individual fibroblast cells (in orange) moving through a three-dimensional matrix (in blue). They found that, in this environment, the cells’ nuclei operate like an engine’s piston to push the cell forward. Credit: University of Pennsylvania/NIDCR
No bacterium is an island.
Many people think of bacteria as tiny Lone Rangers, paddling their flagellar canoes across the desolate petri dish sea. But in “the wild”, bacteria exist as complex, interwoven, constantly competing social communities.
Every scoop of soil is a battlefield of chemical chatter. Species send out molecular messages-in-a-bottle that ride the waves of diffusion to their mates. Some even thread electrical cables between neighboring cells. Now, new research has identified elaborate shared membranes that let single cells swarm as a superorganism …
Check out my latest article for Wired all about a soil bacterium named Myxococcus xanthus. It’s under everyone’s feet right now, and it has developed one of the most elaborate physical webs ever witnessed in bacteria. That’s it up top, devouring a colony of E. coli using its patented rippling wave attack.
It’s a stealth communication network that lets them hunt like a tiny wolfpack. So cool. Plus I got to use a GIF, so double win.
Once you’re done with that, check out this great TED talk from Bonnie Bassler all about how bacteria communicate.
The excretory system of Schmidtea mediterranea, a small freshwater flatworm. S. mediterranea have a remarkable ability to regenerate. Cutting one in half will generate two fully functional flatworms; cutting it into quarters will generate four; and so on. In fact, scientists have shown that even a single cell from one flatworm is capable of regenerating an entire organism.
Image by Hanh Vu, Stowers Institute for Medical Research, Kansas City, Missouri.
Embryonic Rat Thoracic Aorta Medial Layer Myoblast Cells (A-10 Line)
A culture of adherent A-10 rat thoracic aorta cells was fluorescently triple-labeled with MitoTracker Red CMXRos, Alexa Fluor 350 conjugated to phalloidin, and SYTOX Green, targeting the mitochondria, filamentous actin network, and nuclei, respectively.
In this image, the bright red mitochondrial network is superimposed on a deep blue actin cytoskeletal framework centered around the green nuclei.
oops i just deleted this and don't feel like writing it again