Bovine parasite "disguises itself as a chromosome

Clever protozoans hijack the mechanism of cell division for multiplication

The parasite (yellow) is distributed to the two daughter cells during cell division together with the chromosomes (blue). © Conrad von Schubert
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The bovine parasite Theileria has its own survival strategy: it disguises itself as the chromosome of the animal it infests and uses the natural cell division process of its host to multiply. Bernese researchers have now come to the benefits of the beneficiaries.

Parasites have developed various, sometimes sophisticated ways to spread in the organism of their host. Theileria, for example, is a single-celled organism that infects cattle in Africa and large parts of Asia and causes a cancer-like disease - the theileriose.

Tick ​​bites as a transmission path

It is transmitted to the cattle by tick bites, where it first colonizes white blood cells and then turns into red blood cells. From there, it again gets into ticks that feed on the blood of the affected cattle and then infest other cattle.

Cunning propagation strategy

In a study published in the journal "PLoS Biology", a research team led by Dirk Dobbelaere from the Department of Molecular Pathobiology at the University of Bern describes the unique and cunning way Theileria propagates in the organism of cattle.

Transfer to both daughter cells

Once the parasite has settled in the white blood cells of its host, it causes them to divide continuously. During the natural process of cell division, the chromosomes double in size and are pulled through tubular protein strands called microtubules to opposite sides of the cell before it is separated into two parts. display

This ensures that both daughter cells receive an identical set of chromosomes. The clever parasite "disguises" itself as part of this mechanism of the host cell, with the result that it is treated by the host as its own chromosomes. Thus, according to the scientists, it is likewise possible to distribute it evenly over both daughter cells during each cell division and accordingly to multiply exponentially in the organism of cattle.

Free rider of cell division

"The parasite embraces the function of certain host cell molecules and thereby becomes a freelancer of cell division. Thanks to this insight, we now understand much better how the disease works, "says Dobbelaere.

In order to track down the parasite, the scientists had stopped the cell division process at specific points. They were able to observe exactly where the participating host cell molecules and the parasite are at different stages of cell division.

(idw - University of Bern, 29.09.2010 - DLO)