The data on prions-proteinaceous infectious agents-are briefly summarized.
Prions cause several incurable neurodegenerative diseases in mammals, while
in lower eukaryotes the prion properties of proteins may be responsible fo
r the inheritance of some phenotypic traits. The novel experimental models
for finding and studying proteins with prion properties based on the yeast
Saccharomyces cerevisiae and the fungus Podospora anserina are described. T
he significance of the prion phenomenon for biology and medicine is discuss
ed.