Medical Research Council - London Institute of Medical Sciences

Now in our 9th year of bringing you beautiful imagery from biomedical science every day

21 January 2014


The way people’s brains and nervous systems work varies widely – resulting in differences in how each of us think, see, hear and feel – but why is not entirely understood. It’s been known for over 50 years that only one of the two different X-chromosomes in females – one coming from the father and the other from the mother – is active in every cell in the body. But which of the two copies is active varies from cell to cell affecting how different organs, including the brain, work. Now researchers have labelled the two different X-chromosomes red or green in mice, using glowing, genetic ‘tags’, allowing them to see which one is active in every cell. Shown here, the pattern of X activity is very different in the neurons of the left and right sides of the brain, which could explain some of the variation within other mammal species, including humans.

Written by Emma Saxon

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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.

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