Symmetrical faces are supposed to be more attractive, but many of our organs and tissues developed to be asymmetrical – the heart, for example, uses different patterns of blood vessels on its left- and right-hand sides. Researchers are beginning to uncover the mechanisms responsible for left and right-handedness or chirality inside our bodies, and here they found asymmetry even inside single human cells. Tiny ‘bones’ of actin in each cell (green) bend from tiny anchor points (orange) on the surface below, ultimately producing the cells’ structure – its cytoskeleton. Although these cells are re-arranging their cytoskeletons in different ways, many eventually settle into spiral patterns (top right) that can be left or right-handed. The discovery of chirality inside single cells, the building blocks of tissues, suggests that asymmetry plays a vital role in the earliest stages of development, and that the beauty of symmetry is perhaps only skin deep.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.