INFECTIOUS AMYLOID PRECURSOR GENE-SEQUENCES IN PRIMATES USED FOR EXPERIMENTAL TRANSMISSION OF HUMAN SPONGIFORM ENCEPHALOPATHY

Based on the analysis of genomic DNA from single healthy animals of ea ch of five primate species, nucleotide and predicted amino acid sequen ces of the infectious amyloid precursor gene of higher apes (Gorilla a nd Pan) and Old World (Macaca) and New World (Ateles, Saimiri) monkeys showed 95-99% homology to the human sequences, corresponding to their phylogenetic distance from humans. Two of 18 amino acids that differe d from humans resulted from nucleotide changes at sites of mutations i n humans with familial forms of spongiform encephalopathy (a deleted c odon within the codon 51-91 region of 24 bp repeats and a substitution at codon 198). In each of the five animals, codon 129 specified methi onine, the more common of the two polymorphic genotypes in humans. Bec ause genotypic homology did not correlate with experimental transmissi on rates of human spongiform encephalopathy, primary structural simila rity of the infectious amyloid precursor protein in humans and experim ental primates may not be an important factor in disease transmissibil ity.