Prions present a most fascinating biological conundrum. These proteina
ceous particles seem to propagate through a chain reaction in which a
host protein, PrPC, is post-translationally misfolded to form new prio
ns. By this mechanism they 'replicate' without involvement of specific
nucleic acids. Due to their unique modus operandi, prions cause disor
ders tat can be infectious, inherited and sporadic. Transgenetics has
been invaluable in helping to understand this unique phenomenon. Here
we describe some of the most salient contributions of transgenic mice
to this field.