title: Blastomere transplantation in human embryos may be a treatment for single gene diseases.
abstract: OBJECTIVE
  To determine whether human embryos accept blastomere transplants and integrate them normally into the architecture of the developing embryo.
  
  
  METHODS
  A human blastomere transplantation model, involving 44 cryopreserved embryos that were specifically donated to research.
  
  
  METHODS
  Academically affiliated private infertility center.
  
  
  METHODS
  Forty-four human embryos.
  
  
  METHODS
  In 21 experiments, one, two, or three blastomeres were transplanted, using standard microsurgical techniques that are widely used in preimplantation genetic diagnosis (PGD). Embryos were thawed and gender was determined, using established PGD techniques. Male (xy) blastomeres were then transplanted into female (xx) day 3 embryos, and the xy cells were tracked through blastocyst stage (days 5-6) and into the hatching period (day 6), using fluorescent in situ hybridization (FISH).
  
  
  METHODS
  Degree and location of xy cell integration into xx embryos.
  
  
  RESULTS
  High-quality recipient embryos (with 4 to 10 cells) developed uniformly into normal blastocyst stage embryos in 12 of 12 experiments (100%) and integrated donor blastomeres into their architecture, with apparently even distribution of daughter cells; this integration was documented in inner cell mass as well as in trophoectoderm. The intensity of this distribution appeared to correlate with the number of blastomeres transferred. Among nine abnormally developing embryos, only three (33%) demonstrated a normal distribution of offspring donor cells.
  
  
  CONCLUSIONS
  High-quality embryos appear to have the ability to integrate donor blastomeres. Because the treatment of single gene diseases does not require successful treatment of all cells, blastomere transplantation could be explored as a treatment option, which also would greatly enhance efficiency and utilization of preimplantation genetic diagnosis.
authors.affiliation: Center for Human Reproduction, New York, New York, USA. chrjournal@aol.com
authors.forename: Norbert
authors.initials: N
authors.lastname: Gleicher
authors.forename: Ya Xu
authors.initials: YX
authors.lastname: Tang
mesh_terms: D001755:Blastocyst / Q000166:cytology; D001757:Blastomeres / Q000637:transplantation*; D004622:Embryo, Mammalian / Q000166:cytology / Q000601:surgery*; D005314:Embryonic and Fetal Development; D005260:Female; D030342:Genetic Diseases, Inborn / Q000628:therapy; D006801:Humans; D008297:Male; D008846:Micromanipulation