ABSTRACT
Microsatellite sites were analysed with DNA screening software by using about 148 kilobases (kb) of the human genomic DNA sequence GenBank accession number (acc. no.) which includes the genes PRNP, PRND and PRNT. Regarding microsatellites (MS) with at least four repeats and base replacements within the repetitive motifs<10%, 127 sites were found. Sixteen of the sites were analysed and nine of them proved to be polymorphic with up to nine alleles per site. Frequencies<0.95 of the predominant allele were observed for all polymorphic sites, and frequencies<0.4 for four sites. Some allelic DNA sequences were not only different in microsatellite repeats but also in flanking regions. Distances between microsatellite sites were in average of 1.2 kb and allow the identification of a number of further informative markers in the prion protein gene complex. The large number of polymorphic sites within a narrow chromosomal interval can be applied to study the origin of alleles as well as the association to the incidence of diseases.
Subject(s)
Microsatellite Repeats/genetics , Polymorphism, Genetic , Prions/genetics , Adult , Aged , Aged, 80 and over , Alleles , Amyloid/genetics , Base Sequence , Codon/genetics , DNA/chemistry , DNA/genetics , Female , GPI-Linked Proteins , Gene Frequency , Humans , Male , Middle Aged , Molecular Sequence Data , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Polymorphism, Single Nucleotide , Prion Proteins , Protein Precursors/genetics , Sequence Analysis, DNA , Sequence Homology, Nucleic AcidABSTRACT
This study describes genetic differences in resistance/susceptibility to pseudorabies virus (PrV) between European Large White and Chinese Meishan pigs, with a mapping of quantitative trait loci (QTL) obtained from a genome-wide scan in F(2) animals. Eighty-nine F(2) pigs were challenged intranasally at 12 weeks with 10(5) p.f.u. of the wild-type PrV strain NIA-3. For QTL analysis, 85 microsatellite markers, evenly spaced on the 18 porcine autosomes and on the pseudoautosomal region of the X chromosome, were genotyped. All pigs developed clinical signs, i.e. fever, from 3 to 7 days p.i. The pure-bred Large White pigs, the F(1) and three-quarters of the F(2) animals, but none of the Meishan pigs, developed neurological symptoms and died or were euthanized. QTLs for appearance/non-appearance of neurological symptoms were found on chromosomes 9, 5, 6 and 13. They explained 10.6-17.9% of F(2) phenotypic variance. QTL effects for rectal temperature after PrV challenge were found on chromosomes 2, 4, 8, 10, 11 and 16. Effects on chromosomes 9, 10 and 11 were significant on a genome-wide level. The results present chromosomal regions that are associated with presence/absence of neurological symptoms as well as temperature course after intranasal challenge with NIA-3. The QTLs are in proximity to important candidate genes that are assumed to play crucial roles in host defence against PrV.
