title: [Difference analysis of genome-wide DNA methylation status of CpG islands between the monozygotic twins with disconcordant phenotypes of chronic hepatitis B virus infection].
abstract: OBJECTIVE
  To analyse the difference of genome-wide DNA methylation status of CpG island between the monozygotic twins with disconcordant phenotype of HBV infection and to discover possible differentially methylated genes.
  
  
  METHODS
  Modified AIMS (amplification of inter-methylated sites) method was adopted. According to the frequent sites of CpG islands (-CGCG- and -CCGG-), three groups of isochizomers with distinct methylation sensitivity (Sma I-Xma I, Hpa II-Msp I and BssH II-Pau I/BseP I) were used to modify the AIMS method. The modified AIMS method combined with Personal Molecular Imager FX system analysis and radioautographic analysis was used to make the global detection of the methylome of CpG islands. Multiple anonymous bands were compared between the twins with the Quantity One bio-soft. The different bands were cloned into T vectors and positive clones were sequenced. BLAST analysis of positive clone sequences was conducted to give the clues for the differential methylated genes between monozygotic twins with discordant phenotype of HBV infection.
  
  
  RESULTS
  Nearly the same bands were found between one pair of twins with concordant phenotype of HBV infection. Different methylated bands were found not only between monozygotic twins with concordant phenotype but also between those with disconcordant phenotype. More differential methylated bands were found in the latter groups. By BLAST analysis with sequences of differential methylated bands, four possible genes were got. These genes might relate to the monozygotic twins with disconcordant phenotype of chronic HBV infection.
  
  
  CONCLUSIONS
  Differential methylation of genes occurs in monozygotic twins with discordant phenotype of HBV infection. Whether these changes are involved in the pathogenesis of different phenotypes needs further elucidation.
authors.affiliation: Institute of Infectious Diseases of PLA, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Bao-yan
authors.initials: BY
authors.lastname: Xu
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Wang
authors.forename: Guo-hong
authors.initials: GH
authors.lastname: Deng
authors.forename: Yuan-hui
authors.initials: YH
authors.lastname: Luo
authors.forename: Ze-li
authors.initials: ZL
authors.lastname: Du
authors.forename: Lin
authors.initials: L
authors.lastname: Lan
authors.forename: Yan-ping
authors.initials: YP
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018899:CpG Islands; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D015894:Genome, Human; D019694:Hepatitis B, Chronic / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D010641:Phenotype; D014430:Twins, Monozygotic / Q000235:genetics*