In the past 20 years, the expression of PrPC in the placental mammals central nervous system (CNS) has been intensely studied. A role for the PrP gene in mouse embryogenesis has been proposed. In addition, the expression of PrPC in adult chickens has also been investigated. However, the expression of PrPC in the CNS of marsupial mammals has not been previously explored. Here, we show for the first time the expression pattern profile of PrPC during post-natal development of a methaterian marsupial: the South-American short-tailed opossum (Monodelphis domestica). Like in other mammals the expression of the protein is developmentally regulated. In the newly born opossum PrPC signal is detected from P15 onward in the hippocampus, the thalamus and the cortex. Differently from the mouse the PrPC signal is not present in the white matter fiber bundles of the septo and of the thalamolimbic neurocircuitry. Prion diseases have been so far reported in eutherian mammals but not in methaterian ...
