A developing organisms needs axes for orientation: Where is the top, where the lower part of the body, back and front? A third axis defines where the left and the right side goes. If you look at the surface of our body, there is a clear axis with a symetrically mirrored left and right side. However, if you look at the inside, the organs are not at all arranged in a symmetric manner. How do cells break the left-right symmetry?
The Grill Lab uncovered a novel activity of the actomyosin cortex in C. elegans at the 4-cell stage: It generates active torques, counter-rotating flows that, in a screw-like motion, facilitate symmetry breaking
Sundar Ram Naganathan, Sebastian Fürthauer, Masatoshi Nishikawa, Frank Jülicher, Stephan W Grill: Active torque generation by the actomyosin cell cortex drives left-right symmetry breaking
eLife, 17 December 2014