title: Cerebellum-specific and age-dependent expression of an endogenous retrovirus with intact coding potential.
abstract: BACKGROUND
  Endogenous retroviruses (ERVs), including murine leukemia virus (MuLV) type-ERVs (MuLV-ERVs), are presumed to occupy ~10% of the mouse genome. In this study, following the identification of a full-length MuLV-ERV by in silico survey of the C57BL/6J mouse genome, its distribution in different mouse strains and expression characteristics were investigated.
  
  
  RESULTS
  Application of a set of ERV mining protocols identified a MuLV-ERV locus with full coding potential on chromosome 8 (named ERVmch8). It appears that ERVmch8 shares the same genomic locus with a replication-incompetent MuLV-ERV, called Emv2; however, it was not confirmed due to a lack of relevant annotation and Emv2 sequence information. The ERVmch8 sequence was more prevalent in laboratory strains compared to wild-derived strains. Among 16 different tissues of ~12 week-old female C57BL/6J mice, brain homogenate was the only tissue with evident expression of ERVmch8. Further ERVmch8 expression analysis in six different brain compartments and four peripheral neuronal tissues of C57BL/6J mice revealed no significant expression except for the cerebellum in which the ERVmch8 locus' low methylation status was unique compared to the other brain compartments. The ERVmch8 locus was found to be surrounded by genes associated with neuronal development and/or inflammation. Interestingly, cerebellum-specific ERVmch8 expression was age-dependent with almost no expression at 2 weeks and a plateau at 6 weeks.
  
  
  CONCLUSIONS
  The ecotropic ERVmch8 locus on the C57BL/6J mouse genome was relatively undermethylated in the cerebellum, and its expression was cerebellum-specific and age-dependent.
authors: Department of Surgery, University of California, Davis, Sacramento, CA, USA.
authors: Kang-Hoon
authors: KH
authors: Lee
authors: Makoto
authors: M
authors: Horiuchi
authors: Takayuki
authors: T
authors: Itoh
authors: David G
authors: DG
authors: Greenhalgh
authors: Kiho
authors: K
authors: Cho
mesh_terms: D000367:Age Factors; D000818:Animals; D001483:Base Sequence; D002531:Cerebellum / Q000821:virology*; D033481:Chromosomes, Mammalian / Q000235:genetics / Q000821:virology; D003062:Codon; D020077:Endogenous Retroviruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D005260:Female; D015967:Gene Expression Regulation, Viral; D009052:Leukemia Virus, Murine / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D051379:Mice / Q000235:genetics / Q000821:virology*; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009928:Organ Specificity; D010802:Phylogeny; D014779:Virus Replication
chemical_list: D003062:Codon