title: Genetic and epigenetic X-chromosome variations in a parthenogenetic human embryonic stem cell line.
abstract: OBJECTIVE
  To assess the genetic and epigenetic status of parthenogenetic human embryonic stem cells (phESCs).
  
  
  METHODS
  Cytogenetics, X chromosome inactivation (XCI) and gene expression patterns were analyzed in one phESC line (FY-phES-018) that was derived from our laboratory.
  
  
  RESULTS
  FY-phES-018 cells displayed the classical characteristics of normal hESCs. These cells had a 46, XX karyotype, and no inactive X chromosomes were observed before passage 20. After being cultured long term in vitro, some cells lost one X, and the proportion of cells with only one X gradually increased. At passage 35, almost all the cells displayed a 45, XO karyotype. Interestingly, at passage 45, the recovery of the X-chromosome was observed, and XCI became detectable; the mosaic ratio of 46, XX to 45, XO was 67:33. After passage 60, most cells displayed the 46, XX karyotype again with a mosaic ratio of 97:3. Some aberrant genomic imprinting was also observed in these cells.
  
  
  CONCLUSIONS
  The phESCs line FY-phES-018 is both genetically and epigenetically unstable; therefore, further research is needed before using these cells.
authors.affiliation: Guangzhou Key Laboratory of Reproductive and Genetics; Institute of Gynecology and Obstetrics, The Third Affiliated Hospital of Guangzhou Medical College, Guangzhou, 510150, China.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Liu
authors.forename: Yifei
authors.initials: Y
authors.lastname: Yin
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Jiang
authors.forename: Chaohui
authors.initials: C
authors.lastname: Kou
authors.forename: Yumei
authors.initials: Y
authors.lastname: Luo
authors.forename: Shengchang
authors.initials: S
authors.lastname: Huang
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Zheng
authors.forename: Shaoying
authors.initials: S
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Liyuan
authors.initials: L
authors.lastname: Guo
authors.forename: Shaorong
authors.initials: S
authors.lastname: Gao
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Sun
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D041321:Chromosomes, Human, X / Q000235:genetics*; D016172:DNA Fingerprinting; D019175:DNA Methylation; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000166:cytology*; D057890:Epigenomics / Q000379:methods*; D018392:Genomic Imprinting; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D020411:Oligonucleotide Array Sequence Analysis; D010312:Parthenogenesis; D015854:Up-Regulation; D049951:X Chromosome Inactivation