Highly conserved prion protein sequences in random bred cats with three novel synonymous PRNP gene variants

Transmissible spongiform encephalopathies are infectious, fatal, neurodegenerative diseases that affect both humans and animals. They occur as a result of misfolding of prion protein. In some species, variations in prion protein gene (PRNP) were associated with susceptibility to prion diseases. To date, only a few studies have investigated prion protein in cats. For this reason, this study aims to identify feline PRNP polymorphisms in random-bred cats. DNA isolation, PCR and 922 bp amplicon sequencing were performed in order to detect PRNP gene variants in 74 cat samples collected from Istanbul, north-western part of Turkey. Results were evaluated by using SPSS 25.0, HAPLOTYPE ANALYSIS 1.05, DnaSP v6, SRPLOT and PHYLOVIZ Online. In total, eleven polymorphisms including 10 SNPs and a 27 bp in/del polymorphism in the tandem repeat region were observed. Three of these SNPs, c.201C>A, c.225C>T, c.228A>C, were detected for the first time. All SNPs in the open reading frame were synonymous, so no amino acid variation was detected in the prion protein sequence. A total of 28 haplotypes were observed, including 8 major haplotypes with frequencies ≥ 0.05. The results indicating that the prion protein is conserved in cats from north-western Turkey, in contrast to other samples from this country, point to possible differences in the PRNP gene between relatively closely located populations.