Prion octapeptide-repeat polymorphism in Polish Black-and-White cattle.

Area of Science:

• Animal Genetics
• Molecular Biology
• Veterinary Science

Background:

• The bovine prion protein gene (PRNP) plays a role in neurological health.
• Understanding PRNP gene variants is crucial for cattle breeding and disease management.
• Previous studies have not extensively analyzed PRNP in diverse Polish Black-and-White cattle populations.

Purpose of the Study:

• To analyze the genetic polymorphism of the PRNP gene in a Polish Black-and-White cattle population.
• To determine the frequencies of different PRNP genotypes and alleles across various cattle groups.
• To investigate potential associations between PRNP genotypes and cattle management or selection practices.

Main Methods:

• Polymerase Chain Reaction (PCR) analysis was used to identify PRNP gene variants.
• Genotyping was performed on AI sires, young tested bulls, bull-dams, and commercial cows.
• Allele and genotype frequencies were calculated and compared across different population groups.

Main Results:

• Two PRNP gene variants (349 bp and 373 bp) resulted in three genotypes: PRNP 6/6, PRNP 6/5, and PRNP 5/5.
• The overall allele frequency was 0.894 for PRNP 6 and 0.106 for PRNP 5.
• Commercial cows showed a significantly higher frequency of the PRNP 5 allele (q=0.137) compared to AI sires (q=0.077), young bulls (q=0.052), and bull-dams (q=0.084).
• Homozygous PRNP 5/5 genotypes were found in bull-dams and commercial cows, but not in AI sires or young bulls.

Conclusions:

• Significant differences in PRNP allele frequencies exist between male breeding stock and female commercial/dam populations.
• The presence of PRNP 5/5 homozygotes in females suggests potential selection impacts or population-specific genetic structures.
• Further research is warranted to explore the functional implications of PRNP variants in cattle health and productivity.