When a cell divides, its duplicated chromosomes have to be
shared equally between the two daughter cells. Cells manage this
feat by lining up replicated chromosomes along their equators
during mitosis, and then pulling sister chromatids apart to the
right destinations. But Theileria, an intracellular parasitic
protozoan, also needs to divide when its host cell undergoes
mitosis. Dirk Dobbelaere and colleagues at the University of
Bern have now shown how Theileria hijacks the host cell’s
mitotic machinery to ensure its continued survival (PLoS Biol,
8:e1000499, 2010). Some species within the genus Theileria cause
variants of theileriosis, an economically important tick-borne
disease that affects cattle in the tropics and subtropics. The
parasite infects white blood cells, but unlike the malaria
parasite Plasmodium, to which it is closely related, Theileria
dissolves the enclosing membrane soon after infection and takes
up residence in the cytoplasm. It rapidly latches onto host
microtubules and differentiates,