Variation in the prion protein gene (PRNP) open reading frame sequence in French cervids

Area of Science:

• Veterinary Medicine
• Genetics
• Wildlife Disease Ecology

Background:

• Chronic Wasting Disease (CWD) is a prion-related illness affecting cervids, posing a significant public health concern, particularly with its recent emergence in Europe.
• Prion protein gene (PRNP) polymorphisms are known to influence susceptibility and transmission of prion diseases in various mammalian species.

Purpose of the Study:

• To investigate the distribution of PRNP gene polymorphisms in French roe deer (Capreolus capreolus) and red deer (Cervus elaphus).
• To assess the potential impact of PRNP genetic variation on CWD susceptibility and spread within French cervid populations.

Main Methods:

• Sequencing of the prion protein gene (PRNP) open reading frame (ORF) in 2114 cervids (1116 roe deer, 998 red deer) from France.
• Analysis of PRNP polymorphisms, including non-synonymous and synonymous substitutions, and a novel deletion (Δ69-77) in red deer.
• Haplotype and genotype analysis for PRNP in animals with multiple polymorphisms.

Main Results:

• French roe deer populations were largely monomorphic for PRNP, with only one heterozygous animal identified with a G37A mutation.
• Red deer displayed greater genetic diversity, with identified non-synonymous substitutions (T98A, Q226E), synonymous substitutions, and a 24bp deletion (Δ69-77).
• Significant regional variations in PRNP substitution frequencies were observed in French red deer, with six haplotypes and twelve genotypes identified.

Conclusions:

• The PRNP gene in French roe deer appears highly conserved, suggesting potential homogeneity in CWD susceptibility.
• French red deer exhibit greater PRNP genetic diversity, which may influence their susceptibility and the epidemiological dynamics of CWD.
• Findings align with European phylogeographic studies, highlighting species-specific patterns of PRNP variation relevant to prion disease surveillance.