Different alleles of the prion protein gene (PRNP) of human and sheep are known to be associated with varying susceptibilities to transmissible spongiform encephalopathies. However, no polymorphisms in the bovine PRNP gene with an effect on susceptibility to prion diseases have been identified to date. In this study we investigated such polymorphisms in German cattle; 48 healthy animals from six different German cattle breeds and 43 cattle with bovine spongiform encephalopathy (BSE) were analyzed. In contrast to previous studies, all three exons as well as the promoter region of the PRNP gene were investigated. Sequence variants in the bovine PRNP gene could have an impact on the amino acid sequence or the expression level of the prion protein and thus on susceptibility to BSE. We identified a total of 60 polymorphisms in the PRNP gene of German cattle. Of these 60 polymorphisms, 36 were newly identified, whereas 24 of these polymorphisms had been described previously. We did not detect any novel polymorphisms affecting the amino acid sequence of the prion protein. However, we identified a 23-bp insertion/deletion polymorphism in the putative PRNP promoter region that shows a significant association with BSE susceptibility in our animals.

A whole-genome scan to detect quantitative trait loci (QTL) for functional traits was performed in the German Holstein cattle population. For this purpose, 263 genetic markers across all autosomes and the pseudoautosomal region of the sex chromosomes were genotyped in 16 granddaughter-design families with 872 sons. The traits investigated were deregressed breedingvalues for maternal and direct effects on dystocia (DYSm, DYSd) and stillbirth (STIm, STId) as well as maternal and paternal effects on nonreturn rates of 90 d (NR90m, NR90p). Furthermore, deregressed breeding values for functional herd life (FHL) and daughter yield deviation for somatic cell count (SCC) were investigated. Weighted multimarker regression analyses across families and permutation tests were applied for the detection of QTL and the calculation of statistical significance. A ten percent genomewise significant QTL was localized for DYSm on chromosome 8 and for SCC on chromosome 18. A further 24 putative QTL exceeding the 5% chromosomewise threshold were detected. On chromosomes 7, 8, 10, 18, and X/Yps, coincidence of QTL for several traits was observed. Our results suggest that loci with influence on udder health may also contribute to genetic variance of longevity. Prior to implementation of these QTL in marker assisted selection programs for functional traits, information about direct and correlated effects of these QTL as well as fine mapping of their chromosomal positions is required.

Species fraud and product mislabelling in processed food, albeit not being a direct health issue, often results in consumer distrust. Therefore methods for quantification of undeclared species are needed. Targeting mitochondrial DNA, e.g. CYTB gene, for species quantification is unsuitable, due to a fivefold inter-tissue variation in mtDNA content per cell resulting in either an under- (-70%) or overestimation (+160%) of species DNA contents. Here, we describe a reliable two-step droplet digital PCR (ddPCR) assay targeting the nuclear F2 gene for precise quantification of cattle, horse, and pig in processed meat products. The ddPCR assay is advantageous over qPCR showing a limit of quantification (LOQ) and detection (LOD) in different meat products of 0.01% and 0.001%, respectively. The specificity was verified in 14 different species. Hence, determining F2 in food by ddPCR can be recommended for quality assurance and control in production systems.

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