title: Presence and integration of HBV DNA in mouse oocytes.
abstract: OBJECTIVE
  Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied.
  
  
  METHODS
  Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes.
  
  
  RESULTS
  PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1,000 metaphases presented positive signals.
  
  
  CONCLUSIONS
  HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and to integrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.
authors.affiliation: Research Center of Reproductive Medicine, Shantou University Medical College, 22 Xinling Road, Shantou 515041, Guangdong Province, China. thhuang@stu.edu.cn
authors.forename: Tian-Hua
authors.initials: TH
authors.lastname: Huang
authors.forename: Qing-Jian
authors.initials: QJ
authors.lastname: Zhang
authors.forename: Qing-Dong
authors.initials: QD
authors.lastname: Xie
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zeng
authors.forename: Xi-Fan
authors.initials: XF
authors.lastname: Zeng
mesh_terms: D000818:Animals; D004279:DNA, Viral / Q000502:physiology; D005260:Female; D006509:Hepatitis B / Q000635:transmission* / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000254:growth & development*; D018445:Infectious Disease Transmission, Vertical; D051379:Mice; D009865:Oocytes / Q000821:virology*; D016662:Virus Integration
chemical_list: D004279:DNA, Viral