Tighten Your Belt : Cells that line the surfaces and cavities of your body are packed tightly together, like bricks in a wall. Your skin, the lining of your mouth or stomach, or blood vessels are springy..pulling back when stretched. How do they stay in shape?
⇛Scientists have discovered that each cell has a tiny belt that acts like a rubber band. Cables, made of actin filaments (in red) are crosslinked and connected together by alpha actinin (blue). The overlapping fluorescent signals color them purple in the image. Motor proteins, known as myosin (green), power this belt and keep it taut. They do this by pulling on the interdigitating cables so that they slide past each other. A variation of this same assembly makes your muscles contract!
⇛Notice the beautiful symmetry in the arrangement of these molecules all around the cell. Even the junctions, where three cells meet, maintains its ordered arrangement of cables and motors. This brought to mind the poet Blake (1757–1827):
“Tiger, tiger, burning bright
In the forests of the night,
What immortal hand or eye
Dare frame thy fearful symmetry?”
⇛Reference: Ebrahim et al., 2013 NMII Forms a Contractile Transcellular Sarcomeric Network to Regulate Apical Cell Junctions and Tissue Geometry. Current Biology ▶ http://goo.gl/Pwp7F