Manfred Eigen und Peter Schuster
haben das ja vor 25 Jahren schon postuliert-eine Art Nicht-Lebensform(einzeln), die aber in der Gruppe quasi intelligent dem Selektionsdruck ausweicht, und resistent werden kann.
Die gängige Theorie, daß Prionen einfach "verseuchtes" Eiweiß sind,greift hier zu kurz. Auch die These, daß die Neuronalen Netzwerke quasi "zumüllen" und deswegen über den Jordan gehen, ist da nicht weitreichend genug.
und im Januar war das ja in Science, eine geklonte Prionenkolonie, die "mutiert", obwohl ja quasi "nicht-Leben" vorliegt.
Darwinian Evolution of Prions in Cell Culture
Jiali Li, Shawn Browning, Sukhvir P. Mahal, Anja M. Oelschlegel, Charles Weissmann*
Prions are infectious proteins consisting mainly of PrPSc, a β sheet–rich conformer of the normal host protein PrPC, and occur in different strains. Strain identity is thought to be encoded by PrPSc conformation. We found that biologically cloned prion populations gradually became heterogeneous by accumulating "mutants," and selective pressures resulted in the emergence of different mutants as major constituents of the evolving population. Thus, when transferred from brain to cultured cells, "cell-adapted" prions outcompeted their "brain-adapted" counterparts, and the opposite occurred when prions were returned from cells to brain. Similarly, the inhibitor swainsonine selected for a resistant substrain, whereas, in its absence, the susceptible substrain outgrew its resistant counterpart. Prions, albeit devoid of a nucleic acid genome, are thus subject to mutation and selective amplification.
Department of Infectology, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA.
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