PRNP polymorphism frequencies in U.S. cattle populations. PRNP polymorphism frequencies are shown for populations of Bos taurus (n = 94), Holstein (n = 86), Composite of U.S. Brahman (n = 20), British (n = 39), and Continental (n = 51). Hatched bars represent the proportion of polymorphisms where the minor allele was observed in only one animal (singleton). Polymorphism numbers are shown above the bars.
Clawson et al. BMC Genetics 2006 7:51 doi:10.1186/1471-2156-7-51