title: Derivation of the first Swiss human embryonic stem cell line from a single blastomere of an arrested four-cell stage embryo.
abstract: BACKGROUND
  Human embryonic stem cells (hESC) hold enormous potential for regenerative medicine. So far, the majority of hESC lines have been derived from the isolated inner cell mass (ICM) of blastocysts of variable quality, and several of them from low-grade embryos. Moreover, most of the lines have been obtained in media containing animal components such as foetal bovine serum. We aimed to derive hESC lines in xeno-free conditions using spare embryos frozen in Switzerland before 2001.
  
  
  METHODS
  In cooperation with Swiss IVF centres we collected up to 199 donated embryos frozen between 1988 and 2000 at different stages of development.
  
  
  RESULTS
  Embryo quality at thawing showed wide variability, reduced quality and low survival upon culture. Using early arrested embryos (n=46), we report here the first Swiss hESC line, called CH-ES1, derived from a single blastomere of an arrested four-cell-stage embryo. Despite its polyploidy, already present at the third passage, CH-ES1 expressed ESC markers of pluripotency and differentiated into all three germ layers in embryoid bodies in vitro and in teratomas in vivo.
  
  
  CONCLUSIONS
  As the destruction of viable developing embryos, even spare ones, raises serious ethical concerns, deriving hESC lines from arrested embryos may be an alternative approach to avoid embryo destruction. However, given the reduced derivation efficiency they should not be considered a unique and/or selective source of hESC lines.
authors.affiliation: Laboratory of Stem Cell Research, Department of Obstetrics and Gynaecology, Geneva University Hospitals, Geneva, Switzerland. anis.feki@hcuge.ch
authors.forename: Anis
authors.initials: A
authors.lastname: Feki
authors.forename: Alexis
authors.initials: A
authors.lastname: Bosman
authors.forename: Jean-Bernard
authors.initials: JB
authors.lastname: Dubuisson
authors.forename: Olivier
authors.initials: O
authors.lastname: Irion
authors.forename: Sophie
authors.initials: S
authors.lastname: Dahoun
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Pelte
authors.forename: Outi
authors.initials: O
authors.lastname: Hovatta
authors.forename: Marisa E
authors.initials: ME
authors.lastname: Jaconi
mesh_terms: D000818:Animals; D001757:Blastomeres / Q000166:cytology*; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D002460:Cell Line; D015925:Cryopreservation; D019924:Embryo Disposition; D053595:Embryonic Stem Cells / Q000737:chemistry / Q000637:transplantation; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007267:Injections; D007621:Karyotyping; D051379:Mice; D016513:Mice, SCID; D039904:Pluripotent Stem Cells