Unwanted Visitor

Parasites, in all their forms, artfully exploit their unwitting host. Protozoan parasites, like malaria-causing Plasmodium, have evolved clever ways to hoodwink their host. Theileria is similar to Plasmodium but infects cattle and is spread by ticks rather than mosquitoes. Here, a white blood cell infected with Theileria (labelled green) is dividing into two daughter cells and the parasite has adopted a cunning disguise to get itself copied in the process. By covering itself in one of the host’s own proteins Theileria is pulled to opposite ends of the cell by the spindle (stained red) along with the dividing host DNA (stained blue). When the daughter cells split both will be infected and the parasite quickly spreads throughout the blood in this way. Scientists hope that understanding exactly how these tiny tricksters operate will inspire new ways to stop them.

Written by Emma Stoye

• Dirk Dobbelaere
• University of Bern, Switzerland
• Originally published under Creative Commons (CC-BY 2.0)
• Published in PLOS Biology 8(9): e1000499