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Dividing stem cell in the brain

Paula Alexandre, University College London

Download this image from Wellcome Collection.

A stem cell dividing in the brain of a zebrafish before it hatches. Starting at about the 8 o’clock position, this stem cell divides as you move clockwise through the stages to make two different cells: a nerve cell (on the outside, turning from purple to white) and another stem cell (on the inside, staying purple), which can itself go on and continue dividing. The sequence takes 9 hours for the two cells to separate and move apart.

This type of unequal cell division ensures that both types of cell (nerve and stem cell) are made, as both are required for brain growth and development. Zebrafish embryos are transparent, which is ideal for visualising this process.

The image is approximately 250 micrometres (0.25 mm) wide.

Imaging technique: confocal microscopy

A type of light microscopy that uses visible light (usually in the form of one or more lasers) to illuminate part of the object being viewed. Out-of-focus light above and below the point of focus is filtered out and eliminated from the final image. Thin optical slices through an object can be stacked on top of one another to produce a digital 3D reconstruction.

Location where image was created

London, UK

Why did the judges choose this image?

“The image of a dividing stem cell in the brain of a zebrafish is like eye candy for the nerdy – and the artsy and the nosy. Its beautiful symmetry and clock-like progression elegantly illustrate the simultaneous paths of the daughter cells: one a neuron taking on its specialised function, the other a new stem cell able to continue dividing forever. Together, they open up a window into developmental biology, explaining visually what words cannot adequately convey.”

Anne Deconinck, Executive Director of the Koch Institute for Integrative Cancer Research at MIT

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