First report of prion-related protein gene (PRNT) polymorphisms in cattle

Prion diseases are caused by structural changes in normal prion protein (PrP^C). The prion gene family includes four members: prion protein (PRNP), prion-like protein (PRND), shadow of PRNP (SPRN) and prion-related protein (PRNT). Genetic association studies of prion diseases and the other genes in the prion gene family, except for PRNT, have been performed in cattle. Our previous studies indicated that the distribution of PRNP promoter polymorphisms related with bovine spongiform encephalopathy susceptibility is significantly different in Hanwoo (Korean native cattle) and Holstein cattle. However, PRNT polymorphisms have not been reported thus far in cattle. Hence, we examined the PRNT single nucleotide polymorphisms (SNPs) in 315 Hanwoo and 140 Holstein cattle. We found a total of two SNPs, PRNT c.-87C>T and PRNT c.-37G>C, in the 5' untranslated region of exon 2. The c.-87C>T and c.-37G>C genotype (P<0.0001) and allele (P<0.0001) frequencies exhibited significant differences in the distribution between Hanwoo and Holstein cattle. In addition, the c.-37G<C polymorphism was not found in Hanwoo. Interestingly, we did not find any polymorphisms in the ORF of bovine PRNT, which is in contrast with the highly polymorphic ovine PRNT ORF region. This is the first genetic research of the PRNT gene in cattle.