The images were taken by Emmanuel Reynaud, in the group of Ernst Stelzer at the European Molecular Biology Laboratory [EMBL], with a widefield microscope.

The cysts – sacs with a liquid filled lumen surrounded by a single layer of cells – are magnified 400 times. They consist of 50 cells and have a diameter of 350 micrometers, which is five times wider than the thickness of a human hair.

In the left-hand frame, nuclei are stained with blue and microtubules and actin filaments, both components of the cell skeleton, in green and red respectively.

In the other, a similar cyst is shown, this time with nuclei in blue and cell membranes in green.