title: Stem cell research: from what stage may a cell or cellular artifact be qualified as an embryo?
abstract: Until recently, the answer to that question was obvious: from fertilization. The discovery that artificial cellular constructs, by nuclear transfer from adult cells and by other techniques, can produce blastocyst-like structures, which under some conditions may develop into embryos upon uterine implantation, with no fertilization, leads us to consider successful uterine implantation as necessary for the qualification of what is an embryo. This implies replacement of essentialist definitions by evolutionary ones. In addition, the concept of potentiality must not be restricted to genome formation but extended to subsequent epigenetic events in embryonic development.
authors.affiliation: Human Biology Research Center, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: Henri
authors.initials: H
authors.lastname: Atlan
mesh_terms: D016477:Artifacts; D001675:Bioethics; D033041:Embryo Research / Q000941:ethics*; D005260:Female; D005306:Fertilization / Q000502:physiology; D006806:Human Rights / Q000331:legislation & jurisprudence* / Q000592:standards; D006801:Humans; D009865:Oocytes / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D015053:Zygote / Q000166:cytology* / Q000502:physiology*