Biotechnology: Prion-free cows bred

Prion-free cows bred

An American-Japanese research team has bred genetically modified cows that lack the prion protein PrP^{C. This should protect the animals against BSE mad cow disease.}

Misfolded PrP^C is considered to be the trigger of various neurodegenerative diseases such as BSE in cattle, scrapie in sheep or Creutzfeldt-Jakob disease in humans. However, the function of the normally folded protein, which is found in numerous organisms primarily in the nervous system, is still unclear. Genetically modified PrP^{C-free mice develop perfectly normally - but cannot be afflicted with prion diseases.}

The researchers led by Jürgen Richt from the State Center for Animal Diseases in Ames have now taken the same path with cattle. The PrP^{C-free cows appeared normal and he althy at least up to twenty months of age. And in the laboratory, the animals' brain tissue could not be infected with BSE.}

The future will have to show whether the genetically modified cows will remain he althy. In mice, there is evidence that normal PrP^{C plays an important role in the differentiation of neural stem cells into brain cells. (aj)}