Cell to Cell

A huge range of diseases are caused by viruses, affecting every type of living thing from tiny bacteria to humans. But viruses can't live on their own. They spread by infecting living cells, hijacking their host's biological machinery to make new virus particles that burst out of the cell and transmit the infection. However, although thousands of viruses can start an infection in a cell, only a handful of them get passed on. And this means that the most infectious viruses are quickly separated out, spreading from one cell to the next without mixing – like these tomato plant cells infected with viruses labelled with different fluorescent colours. Although the cells in the middle – where the infection started – are a mixture of green and pink, the viruses quickly separate out as the infection spreads outwards. This 'self sorting' process helps to explain why viruses are so effective at spreading.

Written by Kat Arney

Kat Arney

Writer

Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Image by Shuhei Miyashita
• National Institute of Agrobiological Sciences, Japan
• Originally published under a Creative Commons Licence (BY 4.0)
• Research published in PLOS Biology, March 2015