title: CpG distribution and methylation pattern in porcine parvovirus.
abstract: Based on GC content and the observed/expected CpG ratio (oCpGr), we found three major groups among the members of subfamily Parvovirinae: Group I parvoviruses with low GC content and low oCpGr values, Group II with low GC content and high oCpGr values and Group III with high GC content and high oCpGr values. Porcine parvovirus belongs to Group I and it features an ascendant CpG distribution by position in its coding regions similarly to the majority of the parvoviruses. The entire PPV genome remains hypomethylated during the viral lifecycle independently from the tissue of origin. In vitro CpG methylation of the genome has a modest inhibitory effect on PPV replication. The in vitro hypermethylation disappears from the replicating PPV genome suggesting that beside the maintenance DNMT1 the de novo DNMT3a and DNMT3b DNA methyltransferases can't methylate replicating PPV DNA effectively either, despite that the PPV infection does not seem to influence the expression, translation or localization of the DNA methylases. SNP analysis revealed high mutability of the CpG sites in the PPV genome, while introduction of 29 extra CpG sites into the genome has no significant biological effects on PPV replication in vitro. These experiments raise the possibility that beyond natural selection mutational pressure may also significantly contribute to the low level of the CpG sites in the PPV genome.
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: Renáta
authors.initials: R
authors.lastname: Tóth
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Mészáros
authors.affiliation: Division of Genetics, FlyBase, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Rajmund
authors.initials: R
authors.lastname: Stefancsik
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: Dániel
authors.initials: D
authors.lastname: Bartha
authors.affiliation: National Food Chain Safety Office, Veterinary Diagnostic Directorate, Budapest, Hungary.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Bálint
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Zádori
mesh_terms: D001482:Base Composition; D019295:Computational Biology; D018899:CpG Islands; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D019175:DNA Methylation; D019143:Evolution, Molecular; D016679:Genome, Viral / Q000235:genetics; D028323:Parvovirus, Porcine / Q000235:genetics* / Q000502:physiology; D014176:Protein Biosynthesis; D014158:Transcription, Genetic; D014779:Virus Replication
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases