Abstract
Porcine circovirus type 2 (PCV2) is the etiological agent of post-weaning multisystemic wasting syndrome (PMWS). The original prevalent genotype, PCV2a, has been replaced by genotypes 2b and 2d in the swine population worldwide. The Rep protein is critical for viral replication. Comparison of a large number of Rep protein amino acid (aa) sequences showed that three sites distinguish genotype 2b from genotype 2d. In order to analyze the effect of exchanging the amino acids (asparagine and serine) at position 6 in the Rep proteins of PCV2b and PCV2d, two wild-type and two mutant viruses were rescued. Real-time quantitative PCR and a one-step growth curve were used to determine the viral load to assess the replication ability of the rescued viruses. The results showed that there was no significant difference in in vitro performance between the wild-type PCV2b and the mutated virus, while the mutation of PCV2d enhanced viral replication.
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References
Breitbart M, Delwart E, Rosario K, Segalés J, Varsani A & ICTV Report Consortium (2017) Ictv virus taxonomy profile: circoviridae. J Gen Virol 98(8):1997–1998. https://doi.org/10.1099/jgv.0.000871
An D, Roh I, Song D, Park C, Park BK (2007) Phylogenetic characterization of porcine circovirus type 2 in PMWS and PDNS Korean pigs between 1999 and 2006. Virus Res 129:115–122. https://doi.org/10.1016/i.virusres.2007.06.024
Franzo G, Segalés J (2018) Porcine circovirus 2 (PCV-2) genotype update and proposal of a new genotyping methodology. PLoS ONE 13(12):e0208585. https://doi.org/10.1371/journal.pone.0208585
Wang S, Xin C, Wu X, Shi J, Peng Z, Sun P et al (2020) Genetic characterization of porcine circovirus type 2 from 2013 to 2018 in Shandong Province, China. Vet Med Sci. https://doi.org/10.1002/vms3.196
Mankertz A, Hillenbrand B (2001) Replication of porcine circovirus type 1 requires two proteins encoded by the viral rep gene. Virology 279(2):429–438. https://doi.org/10.1006/viro.2000.0730
Fenaux M, Opriessnig T, Halbur P, Elvinger F (2004) Meng X (2004) Two amino acid mutations in the capsid protein of type 2 porcine circovirus (PCV2) enhanced PCV2 replication in vitro and attenuated the virus in vivo. J Virol 78(24):13440–13446. https://doi.org/10.1128/JVI.78.24.13440-13446.2004
Shi J, Peng Z, Fu F et al (2015) Mutant Rep protein of the porcine circovirus type 2 N-glycosylation: 23–25aa, 256–258aa mutation reduced virus replication but 286–288aa mutation enhanced virus replication in PK-15 cells. Vet Microbiol 177(3–4):370–372. https://doi.org/10.1016/j.vetmic.2015.03.016
Zhang L et al (2018) The correlation between the mutual deletions of amino acids within porcine circovirus rep protein and the discrepancy of replication. Microbial Pathogen 117:327–334. https://doi.org/10.1016/j.micpath.2018.02.045
Cheung AK (2003) Transcriptional analysis of porcine circovirus type 2. Virology 305(1):168–180. https://doi.org/10.1006/viro.2002.1733
Hu Y, Cai X, Zhan Y et al (2019) Truncated Rep protein of porcine circovirus 2 (PCV2) caused by a naturally occurring mutation reduced virus replication in PK15 cells. BMC Vet Res 15(1):248. https://doi.org/10.1186/s12917-019-1984-8
Acknowledgments
Thanks to the teachers and students of Shandong Provincial Key Laboratory of Animal Disease Control & Breeding, Shandong Normal University and Qingdao Agricultural University for their help during the experiment.
Funding
This study was partly supported by the National Key R&D Program (2016YFD0500708), the Major Scientific and Technological Innovation Project (MSTIP) (2019JZZY010720), the Shandong Province Modern Agricultural Industry Technology System (SDAIT-08-07), the Shandong Province Agricultural Applications of Major Innovation Projects (SD2019XM003, SD2019XM006), the Key R & D Projects in Shandong Province (2019GNC106151), the Taishan Scholars Project, the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences (CXGC2016B14), and the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences (CXGC2018E10).
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Jun Li and Changxun Xin conceived the project; Changxun Xin designed the experiments; Xiaoyan Wu, Shuo Wang, Jianli Shi, ZhePeng, Chang Liu, and Hong Han performed most of the experiments; Chen Li, Yao Tian, Jiaxin Li, and Shaojian Xu contributed materials and participated in discussions; Xiaoyan Wu wrote the manuscript; Jun Li and Fan Zhang supervised the work and edited the final version of the manuscript, which was read and approved by all of the authors.
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The authors declare that they have no competing interests (neither financial nor non-financial interests). This article does not contain any studies with human participants or animals performed by any of the authors.
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Wu, X., Wang, S., Xin, C. et al. Mutation of the sixth amino acid of the Rep protein has no effect on porcine circovirus 2b but enhances porcine circovirus 2d replication in vitro. Arch Virol 166, 3189–3192 (2021). https://doi.org/10.1007/s00705-021-05217-5
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DOI: https://doi.org/10.1007/s00705-021-05217-5