The prion‐related protein (testis‐specific) gene (PRNT) is highly polymorphic in Portuguese sheep

Abstract

The objective of this study was to search for polymorphisms in the ovine prion-related protein (testis-specific) gene (PRNT). Sampling included 567 sheep from eight Portuguese breeds. The PRNT gene-coding region was analyzed by single-strand conformation polymorphism and sequencing, allowing the identification of the first ovine PRNT polymorphisms, in codons 6, 38, 43 and 48: c.17C>T (p.Ser6Phe, which disrupts a consensus arginine-X-X-serine/threonine motif); c.112G>C (p.Gly38>Arg); c.129T>C and c.144A>G (synonymous) respectively. Polymorphisms in codons 6, 38 and 48 occur simultaneously in 50.6% of the animals, 38.8% presenting as heterozygous. To study the distribution of the polymorphism in codon 43, a restriction fragment length polymorphism analysis was performed. Polymorphic variant c.129C, identified in 89.8% of the animals with 32.8% presented as heterozygous, was considered the wild genotype in Portuguese sheep. Eight different haplotypes which have comparable distribution in all breeds were identified for the PRNT gene. In conclusion, the PRNT coding region is highly polymorphic in sheep, unlike the prion protein 2 dublet gene (PRND), in which we previously found only one synonymous substitution (c.78G>A), in codon 26. The absence or reduced number of PRND heterozygotes (c.78G>A) was significantly associated with three PRNT haplotypes (17C-112G-129T-144A,17CT-112GC-129CT-144AG and 17T-112C-129C-144G), and the only three animals found homozygous at c.78A had the 17C-112G-129C-144A PRNT haplotype. These results constitute evidence of an association between polymorphic variation in PRND and PRNT genes, as has already been observed for PRND and prion protein gene (PRNP).

The First Report of Genetic and Structural Diversities in the SPRN Gene in the Horse, an Animal Resistant to Prion Disease

“…In the horse, one and no polymorphisms have been reported in the PRNP and PRND genes, respectively [13]. In previous studies, a strong LD value between PRNP and PRND gene polymorphisms has been reported in prion disease-susceptible species [20][21][22]. However, the LD value between SNPs of these two genes in horses could not be estimated, as there are no polymorphisms in the equine PRND gene [12].…”

Nucleotide variants in prion-related protein (testis-specific) gene (PRNT) and effects on Chinese and Mongolian sheep phenotypes

“…In 2016, polymorphisms in the sheep PRNT gene were first detected in 567 sheep from eight Portuguese breeds [5]. In that study, two SNPs loci that resulted in missense mutations (p.Ser6Phe and p.Gly38Arg) and two synonymous mutations were identified.…”

“…Recent studies have confirmed the translation of PRNT gene in ovine [3] and goat [4], and corresponding gene structures have also been reported. Based on previous reports, the goat [4] and sheep [5] PRNT are both single-exon genes. Although the gene structure of ovine PRNT is simple, its coding region sequence (CDS) is highly polymorphic.…”

“…Although the gene structure of ovine PRNT is simple, its coding region sequence (CDS) is highly polymorphic. In Portuguese sheep, four SNP loci [g.17C>T (p.Ser6Phe), g.112G>C (p.Gly38Arg), g.129T>C (synonymous), and g.144A>G (synonymous)] have been found and significant correlations between PRND heterozygote (c.78G>A) and three PRNT haplotypes have been identified [5].…”

“…However, to date, available data for East Asian sheep breeds and PRNT polymorphisms have been limited and no study has examined the effect of these polymorphisms on ovine phenotypic traits. Furthermore, considering the linkage of PRND and PRNT [5], the potential for an association between PRNT polymorphisms and economically important sheep traits still needs to be investigated.…”