The Correlation Research Of Polymorphisms Of2Locus In Prion Protein Gene (Prnp) On Yak Spongiform Encephalopathies (Bse) Susceptibility

The prion protein was encoded by the prion protein gene (Prnp) which was the majorgene for affecting bovine spongiform encephalopathy (BSE). To investigate the effect ofpolymorphisms of the prion protein gene (Prnp) on the susceptibility of BSE in Yak (288), inthe present study, the23bp indel in Prnp promoter and the12bp indel in the first intron wereidentified. Statistical analysis of23bp and12bp indel between the cattle and other cattlewhich date has reported in the world. Morever, the Real-time PCR was established to measuremRNA expression level of Prnp of the medulla oblongata in79Yak. For expression ofdifferent haploid type, age, gender and color were carried on the analysis of variance. Theresults were shows as follow:1. The two polymorphism sites of the23bp Indel and12bp Indel of Yak were analysed.The gene frequency and genotype frequency of23bp and12bp in Yak were obtained. In Yak,the23bp allele has three genotypes (I23/I23, I23/D23, D23/D23) which frequencies are0.027,0.113and0.86and the allele frequencies are0.133(I23) and0.867(D23). The12bp allelealso has three genotypes (I12/I12, I12/D12, D12/D12) which frequencies are0.627,0.355and0.018. The allele frequencies are0.804(I12) and0.196(D12). Compared with other date,which has reported from the health and BSE affected cattle in the world, our results show thatthe Yak has a high insertion frequency of12bp, and a low insertion frequency of23bp.2. The haplotype construction was performed based on the23bp indel and12bp indel ofPrnp in Yak. In Zhongdian Yak, the main haplotype is23D12I and the frequency is0.692.3. The relative expression of the Prnp in Yak (medulla oblongata) has a significantdifference in different type haploid (P <0.05). It validation for23bp and12bp indelpolymorphism affects cattle resistance of BSE.4. The relative expression of Prnp gene in Yak (medulla oblongata) has a significantdifference (P <0.05) of haploid type and age, no significant difference (P>0.05) in differentgender and color.The data showed that Prnp relative expression was affected by the insert and deletion of 23bp and12bp on the protein, respectively. Mutation of these lotus is related the BSEsusceptibility in Yak.