Polymorphism of prion protein gene (PRNP) in Nigerian sheep

ABSTRACT

Polymorphism of the prion protein gene (PRNP) gene determines an animal’s susceptibility to scrapie. Three polymorphisms at codons 136, 154, and 171 have been linked to classical scrapie susceptibility, although many variants of PRNP have been reported. However, no study has investigated scrapie susceptibility in Nigerian sheep from the drier agro-climate zones. In this study, we aimed to identify PRNP polymorphism in nucleotide sequences of 126 Nigerian sheep by comparing them with public available studies on scrapie-affected sheep. Further, we deployed Polyphen-2, PROVEAN, and AMYCO analyses to determine the structure changes produced by the non-synonymous SNPs. Nineteen (19) SNPs were found in Nigerian sheep with 14 being non-synonymous. Interestingly, one novel SNP (T718C) was identified. There was a significant difference (P < 0.05) in the allele frequencies of PRNP codon 154 between sheep in Italy and Nigeria. Based on the prediction by Polyphen-2, R154H was probably damaging while H171Q was benign. Contrarily, all SNPs were neutral via PROVEAN analysis while two haplotypes (HYKK and HDKK) had similar amyloid propensity of PRNP with resistance haplotype in Nigerian sheep. Our study provides valuable information that could be possibly adopted in programs targeted at breeding for scrapie resistance in sheep from tropical regions.

KEYWORDS:

• Nigeria
• polymorphism
• prion protein gene
• scrapie
• sheep
• susceptibility

Acknowledgments

We appreciate the important contributions of the Central Abattoir, Ibadan and the Ministry of Agriculture and Rural Development, Oyo State, in Nigeria, who made possible the collection of sheep samples for this study. We recognize all of those who assisted in the success of this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions:

Conceptualization, A.C.A., S.F.B., and A.M.A.; methodology, A.C.A., S.F.B., A.M.A., L.M.N., A.B.O, L.D.R., T.T.Y., and N.A.; software, A.C.A., and S.F.B.; validation, S.F.B., A.M.A., L.M.N., A.B.O., L.D.R., P.M.D., and N.A.; formal analysis, A.C.A., and S.F.B.; investigation, A.C.A., S.F.B., S.C.O., and M.P.H.; resources, A.C.A., A.M.A, A.B.O., N.A., L.D.R., S.L.P., M.M.M., H.S., A.I.M., O.J.S., L.M.N., S.C.O., G.F.M., M.P.H., R.K.B., J.I., H.L.A., and P.M.D.; data curation, A.C.A., S.F.B., and T.T.Y.; writing – original draft preparation, S.F.B., and A.C.A.; writing – review and editing, A.E.S., A.M.A., A.B.O., N.A., L.M.N., S.L.P., M.M.M., H.S., R.K.B., H.L.A., A.I.M., O.J.S., L.D.R., S.C.O., G.F.M., M.P.H., J.I., S.K., M.H.Y., and P.M.D.; visualization, A.C.A., S.F.B., A.M.A., S.K., P.M.D., and A.E.S; supervision, A.C.A.; project administration, A.C.A.; funding acquisition, A.C.A. All authors have read and agreed to the published version of the manuscript.

Data availability statement

Accession no. MZ463500 – MZ463625 https://www.ncbi.nlm.nih.gov/

Institutional review board statement

All experimental procedures in this study were in accordance with Research Guidelines for the Institutional Review Board of Kunming Institute of Zoology, Chinese Academy of Sciences (SMKX-20160524-119) and the Central Abattoir, Ibadan, Ministry of Agriculture and Rural Development, Oyo State, Nigeria. Various sheep were transported from farms in drier agro-climate zones in Nigeria to the Central Abattoir in Ibadan, Nigeria. Hence, all sheep samples in this study were collected at the Central Abattoir, Ibadan.

Informed consent statement:

Not applicable.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19336896.2023.2186767.

Additional information

Funding

This work was supported by the Sino-Africa Joint Research Center, Chinese Academy of Sciences (SAJC202103), and the Animal Branch of the Germplasm Bank of Wild Species, Chinese Academy of Sciences (the Large Research Infrastructure Funding). Also, the Chinese Academy of Sciences President’s International Fellowship Initiative (CAS-PIFI) provided grant support to A.C.A. (2021FYB0006).