The prion gene family is mainly composed of three genes, PRNP, encoding the prion protein (PrP), PRND, encoding Doppel (Dpl), both located on the same genomic locus on mouse chromosome 2 and SPRN, encoding Shadoo (Sho), located on mouse chromosome 7. PRND (prion protein 2 also called Doppel) is a membranean N-glycosylated, glycosylphosphatidylinositol-anchored protein that is found predominantly in testis. PRND gene is found on chromosome 20, approximately 20 kbp downstream of the gene encoding cellular prionprotein, to which it is biochemically and structurally similar. 26947-1-AP antibody detects a 30 kDa glycosylated protein and a 17-20 kDa protein treated by glucosidase.