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Adeola AC, Bello SF, Abdussamad AM, Mark AI, Sanke OJ, Onoja AB, Nneji LM, Abdullahi N, Olaogun SC, Rogo LD, Mangbon GF, Pedro SL, Hiinan MP, Mukhtar MM, Ibrahim J, Saidu H, Dawuda PM, Bala RK, Abdullahi HL, Salako AE, Kdidi S, Yahyaoui MH, Yin TT. Polymorphism of prion protein gene (PRNP) in Nigerian sheep. Prion 2023; 17:44-54. [PMID: 36892181 PMCID: PMC10012947 DOI: 10.1080/19336896.2023.2186767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023] Open
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.
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Affiliation(s)
- Adeniyi C Adeola
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Laboratory of Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Sino-Africa Joint Research Center, Chinese Academy of Sciences, Kunming, China.,Centre for Biotechnology Research, Bayero University, Kano, Nigeria
| | - Semiu F Bello
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Abdussamad M Abdussamad
- Centre for Biotechnology Research, Bayero University, Kano, Nigeria.,Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, Bayero University, Kano, Nigeria
| | - Akanbi I Mark
- Ministry of Agriculture and Rural Development, Secretariat, Ibadan, Nigeria
| | - Oscar J Sanke
- Taraba State Ministry of Agriculture and Natural Resources, Jalingo, Nigeria
| | - Anyebe B Onoja
- Department of Virology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Lotanna M Nneji
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Nasiru Abdullahi
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Bayero University, Kano, Nigeria
| | - Sunday C Olaogun
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria
| | - Lawal D Rogo
- Department of Medical Laboratory Science, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University, Kano, Nigeria
| | | | | | - Manasseh P Hiinan
- Small Ruminant Section, Solomon Kesinton Agro-Allied Limited Iperu-Remo, Ogun State, Nigeria
| | - Muhammad M Mukhtar
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Bayero University, Kano, Nigeria
| | - Jebi Ibrahim
- Department of Veterinary Surgery and Theriogenology, College of Veterinary Medicine, University of Agriculture Makurdi, Makurdi, Nigeria
| | - Hayatu Saidu
- Department of Medical Laboratory Science, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University, Kano, Nigeria
| | - Philip M Dawuda
- Department of Animal Science, Faculty of Agriculture, National University of Lesotho, Lesotho, Southern Africa
| | - Rukayya K Bala
- Centre for Biotechnology Research, Bayero University, Kano, Nigeria
| | - Hadiza L Abdullahi
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, Bayero University, Kano, Nigeria
| | - Adebowale E Salako
- Department of Animal Science, Faculty of Agriculture, University of Ibadan, Ibadan, Nigeria
| | - Samia Kdidi
- Livestock and Wildlife Laboratory, Institut des Régions Arides, Université de Gabes, Medenine, Tunisia
| | - Mohamed Habib Yahyaoui
- Livestock and Wildlife Laboratory, Institut des Régions Arides, Université de Gabes, Medenine, Tunisia
| | - Ting-Ting Yin
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Laboratory of Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
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Silva CJ, Cassmann ED, Greenlee JJ, Erickson-Beltran ML, Requena JR. A Mass Spectrometry-Based Method of Quantifying the Contribution of the Lysine Polymorphism at Position 171 in Sheep PrP. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:245-254. [PMID: 36622794 PMCID: PMC9897214 DOI: 10.1021/jasms.2c00277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
In sheep, the transmissibility and progression of scrapie, a sheep prion (PrPSc) disease, is strongly dependent upon specific amino acid polymorphisms in the natively expressed prion protein (PrPC). Sheep expressing PrPC with lysine (K) polymorphism at position 171 (K171) are partially resistant to oronasal dosing of classical sheep scrapie. In addition, scrapie infected sheep expressing the K171 polymorphism show a longer incubation period compared to sheep homozygous (glutamine (Q)) at position 171. Quantitating the amount of the K171 polymorphism in a sheep scrapie sample can provide important information on the composition of PrPSc. A tryptic peptide, 159R.YPNQVYYRPVDK.Y172, derived from the digestion of 171K recombinant PrP, was identified as an analyte peptide suitable for a multiple reaction monitoring-based analysis. This method, using 15N-labeled analogs and another internal peptide from the proteinase K-resistant core, permits the simultaneous quantitation of the total amount of PrP and the proportion of K171 polymorphism in the sample. Background molecules with similar retention times and transitions were present in samples from scrapie-infected sheep. Proteinase K digestion followed by ultracentrifugation-based isolation or phosphotungstic acid-based isolation were employed to minimize the contribution of those background molecules, making this approach suitable for quantitating the amount of the K171 polymorphism in heterozygous scrapie infected sheep.
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Affiliation(s)
- Christopher J. Silva
- Produce
Safety and Microbiology Research Unit, Western Regional Research Center,
United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States of America
| | - Eric D. Cassmann
- Virus
and Prion Research Unit, National Animal Disease Center, Agricultural
Research Service, United States Department
of Agriculture, Ames, Iowa 50010, United
States of America
| | - Justin J. Greenlee
- Virus
and Prion Research Unit, National Animal Disease Center, Agricultural
Research Service, United States Department
of Agriculture, Ames, Iowa 50010, United
States of America
| | - Melissa L. Erickson-Beltran
- Produce
Safety and Microbiology Research Unit, Western Regional Research Center,
United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States of America
| | - Jésus R. Requena
- CIMUS
Biomedical Research Institute & Department of Medical Sciences, University of Santiago de Compostela−IDIS, 15782 Santiago
de Compostela, Spain
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3
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Differential Accumulation of Misfolded Prion Strains in Natural Hosts of Prion Diseases. Viruses 2021; 13:v13122453. [PMID: 34960722 PMCID: PMC8706046 DOI: 10.3390/v13122453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 01/01/2023] Open
Abstract
Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of neurodegenerative protein misfolding diseases that invariably cause death. TSEs occur when the endogenous cellular prion protein (PrPC) misfolds to form the pathological prion protein (PrPSc), which templates further conversion of PrPC to PrPSc, accumulates, and initiates a cascade of pathologic processes in cells and tissues. Different strains of prion disease within a species are thought to arise from the differential misfolding of the prion protein and have different clinical phenotypes. Different strains of prion disease may also result in differential accumulation of PrPSc in brain regions and tissues of natural hosts. Here, we review differential accumulation that occurs in the retinal ganglion cells, cerebellar cortex and white matter, and plexuses of the enteric nervous system in cattle with bovine spongiform encephalopathy, sheep and goats with scrapie, cervids with chronic wasting disease, and humans with prion diseases. By characterizing TSEs in their natural host, we can better understand the pathogenesis of different prion strains. This information is valuable in the pursuit of evaluating and discovering potential biomarkers and therapeutics for prion diseases.
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Cassmann ED, Frese RD, Greenlee JJ. Second passage of chronic wasting disease of mule deer to sheep by intracranial inoculation compared to classical scrapie. J Vet Diagn Invest 2021; 33:711-720. [PMID: 34047228 DOI: 10.1177/10406387211017615] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The origin of chronic wasting disease (CWD) in cervids is unclear. One hypothesis suggests that CWD originated from scrapie in sheep. We compared the disease phenotype of sheep-adapted CWD to classical scrapie in sheep. We inoculated sheep intracranially with brain homogenate from first-passage mule deer CWD in sheep (sCWDmd). The attack rate in second-passage sheep was 100% (12 of 12). Sheep had prominent lymphoid accumulations of PrPSc reminiscent of classical scrapie. The pattern and distribution of PrPSc in the brains of sheep with CWDmd was similar to scrapie strain 13-7 but different from scrapie strain x124. The western blot glycoprofiles of sCWDmd were indistinguishable from scrapie strain 13-7; however, independent of sheep genotype, glycoprofiles of sCWDmd were different than x124. When sheep genotypes were evaluated individually, there was considerable overlap in the glycoprofiles that precluded significant discrimination between sheep CWD and scrapie strains. Our data suggest that the phenotype of CWD in sheep is indistinguishable from some strains of scrapie in sheep. Given our results, current detection techniques would be unlikely to distinguish CWD in sheep from scrapie in sheep if cross-species transmission occurred naturally. It is unknown if sheep are naturally vulnerable to CWD; however, the susceptibility of sheep after intracranial inoculation and lymphoid accumulation indicates that the species barrier is not absolute.
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Affiliation(s)
- Eric D Cassmann
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA
| | - Rylie D Frese
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA
| | - Justin J Greenlee
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA
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5
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Neuropathology of Animal Prion Diseases. Biomolecules 2021; 11:biom11030466. [PMID: 33801117 PMCID: PMC8004141 DOI: 10.3390/biom11030466] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/04/2021] [Accepted: 03/18/2021] [Indexed: 01/09/2023] Open
Abstract
Transmissible Spongiform Encephalopathies (TSEs) or prion diseases are a fatal group of infectious, inherited and spontaneous neurodegenerative diseases affecting human and animals. They are caused by the conversion of cellular prion protein (PrPC) into a misfolded pathological isoform (PrPSc or prion- proteinaceous infectious particle) that self-propagates by conformational conversion of PrPC. Yet by an unknown mechanism, PrPC can fold into different PrPSc conformers that may result in different prion strains that display specific disease phenotype (incubation time, clinical signs and lesion profile). Although the pathways for neurodegeneration as well as the involvement of brain inflammation in these diseases are not well understood, the spongiform changes, neuronal loss, gliosis and accumulation of PrPSc are the characteristic neuropathological lesions. Scrapie affecting small ruminants was the first identified TSE and has been considered the archetype of prion diseases, though atypical and new animal prion diseases continue to emerge highlighting the importance to investigate the lesion profile in naturally affected animals. In this report, we review the neuropathology and the neuroinflammation of animal prion diseases in natural hosts from scrapie, going through the zoonotic bovine spongiform encephalopathy (BSE), the chronic wasting disease (CWD) to the newly identified camel prion disease (CPD).
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6
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Transmission of the atypical/Nor98 scrapie agent to Suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes. PLoS One 2021; 16:e0246503. [PMID: 33571246 PMCID: PMC7877616 DOI: 10.1371/journal.pone.0246503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/21/2021] [Indexed: 11/25/2022] Open
Abstract
Scrapie is a transmissible spongiform encephalopathy that occurs in sheep. Atypical/Nor98 scrapie occurs in sheep that tend to be resistant to classical scrapie and it is thought to occur spontaneously. The purpose of this study was to test the transmission of the Atypical/Nor98 scrapie agent in three genotypes of Suffolk sheep and characterize the distribution of misfolded prion protein (PrPSc). Ten sheep were intracranially inoculated with brain homogenate from a sheep with Atypical/Nor98 scrapie. All sheep with the ARQ/ARQ and ARQ/ARR genotypes developed Atypical/Nor98 scrapie confirmed by immunohistochemistry, and one sheep with the VRQ/ARQ genotype had detectable PrPSc consistent with Atypical/Nor98 scrapie at the experimental endpoint of 8 years. Sheep with mild early accumulations of PrPSc in the cerebellum had concomitant retinal PrPSc. Accordingly, large amounts of retinal PrPSc were identified in clinically affected sheep and sheep with dense accumulations of PrPSc in the cerebellum.
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Mammadova N, Cassmann ED, Moore SJ, Nicholson EM, Greenlee JJ. Experimental inoculation of CD11c + B1 lymphocytes, CD68 + macrophages, or platelet-rich plasma from scrapie-infected sheep into susceptible sheep results in variable infectivity. Access Microbiol 2020; 2:acmi000155. [PMID: 33195984 PMCID: PMC7656192 DOI: 10.1099/acmi.0.000155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/24/2020] [Indexed: 11/18/2022] Open
Abstract
Many studies have demonstrated prion infectivity in whole blood and blood components in a variety of transmissible spongiform encephalopathies of livestock and rodents, and variant Creutzfeldt–Jakob disease in humans, as well as an association between pathogenic prion protein (PrPSc) and different immune cells (e.g. follicular dendritic cells, T and B lymphocytes, monocytes and tingible body macrophages). To further investigate the role of various blood components in prion disease transmission, we intracranially inoculated genetically susceptible VRQ/ARQ and ARQ/ARQ sheep with inocula composed of CD11c+ B1 lymphocytes, CD68 +macrophages, or platelet-rich plasma derived from clinically ill sheep infected with the US no. 13–7 scrapie agent. At the completion of the study, we found that VRQ/ARQ and ARQ/ARQ sheep inoculated with CD11c+ B1 lymphocytes and CD68+ macrophages developed scrapie with detectable levels of PrPSc in the central nervous system and lymphoreticular system, while those inoculated with platelet-rich plasma did not develop disease and did not have detectable PrPSc by immunohistochemistry or enzyme immunoassay. This study complements and expands on earlier findings that white blood cells harbour prion infectivity, and reports CD11c+ B1 lymphocytes and CD68+ macrophages as additional targets for possible preclinical detection of prion infection in blood.
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Affiliation(s)
- Najiba Mammadova
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA.,Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664
| | - Eric D Cassmann
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA.,Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664
| | - S Jo Moore
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA.,Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664
| | - Eric M Nicholson
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA
| | - Justin J Greenlee
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA
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Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ. BMC Vet Res 2020; 16:383. [PMID: 33032590 PMCID: PMC7545885 DOI: 10.1186/s12917-020-02611-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/05/2020] [Indexed: 11/24/2022] Open
Abstract
Background Transmissible mink encephalopathy (TME) is a fatal neurologic disease of farmed mink. Evidence indicates that TME and L-BSE are similar and may be linked in some outbreaks of TME. We previously transmitted bovine adapted TME (bTME) to sheep. The present study compared ovine passaged bTME (o-bTME) to C-BSE and L-BSE in transgenic mice expressing wild type bovine prion protein (TgBovXV). To directly compare the transmission efficiency of all prion strains in this study, we considered the attack rates and mean incubation periods. Additional methods for strain comparison were utilized including lesion profiles, fibril stability, and western blotting. Results Sheep donor genotype elicited variable disease phenotypes in bovinized mice. Inoculum derived from a sheep with the VRQ/VRQ genotype (o-bTMEVV) resulted in an attack rate, incubation period, western blot profile, and neuropathology most similar to bTME and L-BSE. Conversely, donor material from a sheep with the VRQ/ARQ genotype (o-bTMEAV) elicited a phenotype distinct from o-bTMEVV, bTME and L-BSE. The TSE with the highest transmission efficiency in bovinized mice was L-BSE. The tendency to efficiently transmit to TgBovXV mice decreased in the order bTME, C-BSE, o-bTMEVV, and o-bTMEAV. The transmission efficiency of L-BSE was approximately 1.3 times higher than o-bTMEVV and 3.2 times higher than o-bTMEAV. Conclusions Our findings provide insight on how sheep host genotype modulates strain genesis and influences interspecies transmission characteristics. Given that the transmission efficiencies of L-BSE and bTME are higher than C-BSE, coupled with previous reports of L-BSE transmission to mice expressing the human prion protein, continued monitoring for atypical BSE is advisable in order to prevent occurrences of interspecies transmission that may affect humans or other species.
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Abstract
In sheep, scrapie is a fatal neurologic disease that is caused by a misfolded protein called a prion (designated PrPSc). The normal cellular prion protein (PrPC) is encoded by an endogenous gene, PRNP, that is present in high concentrations within the CNS. Although a broad range of functions has been described for PrPC, its entire range of functions has yet to be fully elucidated. Accumulation of PrPSc results in neurodegeneration. The PRNP gene has several naturally occurring polymorphisms, and there is a strong correlation between scrapie susceptibility and PRNP genotype. The cornerstone of scrapie eradication programs is the selection of scrapie-resistant genotypes to eliminate classical scrapie. Transmission of classical scrapie in sheep occurs during the prenatal and periparturient periods when lambs are highly susceptible. Initially, the scrapie agent is disseminated throughout the lymphoid system and into the CNS. Shedding of the scrapie agent occurs before the onset of clinical signs. In contrast to classical scrapie, atypical scrapie is believed to be a spontaneous disease that occurs in isolated instances in older animals within a flock. The agent that causes atypical scrapie is not considered to be naturally transmissible. Transmission of the scrapie agent to species other than sheep, including deer, has been experimentally demonstrated as has the transmission of nonscrapie prion agents to sheep. The purpose of this review is to outline the current methods for diagnosing scrapie in sheep and the techniques used for studying the pathogenesis and host range of the scrapie agent. Also discussed is the US scrapie eradication program including recent updates.
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Teferedegn EY, Yaman Y, Un C. Five novel PRNP gene polymorphisms and their potential effect on Scrapie susceptibility in three native Ethiopian sheep breeds. BMC Vet Res 2020; 16:122. [PMID: 32349749 PMCID: PMC7189463 DOI: 10.1186/s12917-020-02336-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/15/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Classical scrapie susceptibility in sheep has been linked to three polymorphisms at codon 136, 154, and 171 in the prion protein gene (PRNP) whereas atypical scrapie susceptibility is related to polymorphisms at codon 141. Many other variants over the length of the PRNP have been reported. Some of the variants may play crucial roles in fighting against the emergence of a new form of scrapie disease. Scrapie surveillance, scrapie associated genotyping and PRNP characterization studies have been conducted across the globe. However, such in-depth studies have never addressed the African continent's sheep breeds. Therefore, genotyping native Ethiopian sheep breed's PRNP gene has socioeconomic and scientific merits. This study aimed to identify PRNP variants in three native Ethiopian sheep breeds and their potential effect on scrapie susceptibility. RESULTS Five novel variants were identified in the PRNP gene of three native Ethiopian sheep breeds. Four non-synonymous heterozygous substitutions i.e. H99Q (CAC-- > CAA), H99L (CAC-- > CTA), A116E (GCA-- > GAA), A116T (GCA-- > ACA), and one synonymous N103 N (AAC-- > AAT) were detected. In addition to the novel variants, polymorphisms at codon 126,127,138,142,146,231, and 237 were also identified. The haplotype ARR was observed in Menz and Afar breeds at frequencies of 0.02 and 0.05 respectively. Neither ARR/ARR nor VRQ/VRQ genotypes were identified in the population under study. CONCLUSION Two of the novel variants at codon 99 and 103 that are placed closer to the proteinase K cleavage site and the variant at codon 116 in the palindrome region along with variants at codon 127 in glycine repeat domain may influence the conformational flexibility of prion protein. The rarity of ARR haplotype and the abundance of 141 L variant demonstrated that the present study population was less resistant to classical scrapie and less predisposed to genotype associated atypical scrapie. This study provides a valuable dataset that can be potentially integrated into selective breeding strategies during interbreeding, crossbreeding and help to take precautionary measures against scrapie.
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Affiliation(s)
| | - Yalcin Yaman
- Department of Biometry and Genetics, Bandirma Sheep Research Institute, Bandirma, Balikesir, Turkey
| | - Cemal Un
- Ege University, Department of Biology, Molecular Biology Division, Izmir, Turkey
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11
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Cassmann ED, Moore SJ, Smith JD, Greenlee JJ. Sheep Are Susceptible to the Bovine Adapted Transmissible Mink Encephalopathy Agent by Intracranial Inoculation and Have Evidence of Infectivity in Lymphoid Tissues. Front Vet Sci 2019; 6:430. [PMID: 31850385 PMCID: PMC6895770 DOI: 10.3389/fvets.2019.00430] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/14/2019] [Indexed: 11/13/2022] Open
Abstract
Transmissible mink encephalopathy (TME) is a food borne prion disease. Epidemiological and experimental evidence suggests similarities between the agents of TME and L-BSE. This experiment demonstrates the susceptibility of four different genotypes of sheep to the bovine adapted TME agent by intracranial inoculation. The four genotypes of sheep used in this experiment had polymorphisms corresponding to codons 136, 154, and 171 of the prion gene: V136R154Q171/VRQ, VRQ/ARQ, ARQ/ARQ, and ARQ/ARR. All intracranially inoculated sheep without comorbidities (15/15) developed clinical signs and had detectable PrPSc by immunohistochemistry, western blot, and enzyme immunoassay (EIA). The mean incubation periods in sheep with bovine adapted TME correlated with their relative genotypic susceptibility. There was peripheral distribution of PrPSc in the trigeminal ganglion and neuromuscular spindles; however, unlike classical scrapie and C-BSE in sheep, sheep inoculated with the bovine TME agent did not have immunohistochemically detectable PrPSc in the lymphoid tissue. To rule out the presence of infectivity, the lymph nodes of two sheep genotypes, VRQ/VRQ, and ARQ/ARQ, were bioassayed in transgenic mice expressing ovine prion protein. Mice intracranially inoculated with retropharyngeal lymph node from a VRQ/VRQ sheep were EIA positive (3/17) indicating that sheep inoculated with the bovine TME agent harbor infectivity in their lymph nodes despite a lack of detection with conventional immunoassays. Western blot analysis demonstrated similarities in the migration patterns between bovine TME in sheep, the bovine adapted TME inoculum, and L-BSE. Overall, these results demonstrate that sheep are susceptible to the bovine adapted TME agent, and the tissue distribution of PrPSc in sheep with bovine TME is distinct from classical scrapie.
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Affiliation(s)
- Eric D Cassmann
- Virus and Prion Research Unit, United States Department of Agriculture, National Animal Disease Center, Agricultural Research Service, Ames, IA, United States
| | - S Jo Moore
- Virus and Prion Research Unit, United States Department of Agriculture, National Animal Disease Center, Agricultural Research Service, Ames, IA, United States
| | - Jodi D Smith
- Department of Veterinary Pathology, Iowa State University, Ames, IA, United States
| | - Justin J Greenlee
- Virus and Prion Research Unit, United States Department of Agriculture, National Animal Disease Center, Agricultural Research Service, Ames, IA, United States
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