title: Spermatogonial survival after grafting human testicular tissue to immunodeficient mice.
abstract: BACKGROUND
  The xenografting of pre-pubertal human testicular tissue to an immunodeficient mouse is a theoretical strategy for restoring fertility in childhood cancer patients, while circumventing the risk of malignant recurrence. This study aimed at comparing the grafting of pre-pubertal and adult murine testicular tissue, as well as that of human adult testicular tissue, to two immunodeficient recipients, i.e. Swiss Nude mice and SCID-NOD mice.
  
  
  METHODS
  In this study, we evaluated the survival of pre-pubertal and adult murine testicular tissues, and that of adult human testicular tissue after subcutaneous grafting to immunodeficient mice.
  
  
  RESULTS
  After allografting pre-pubertal testicular tissue pieces, meiotic cells were observed in 69.1% of the grafts, while complete spermatogenesis was observed in 30.9%. All grafts of adult murine testicular tissue and 59.5% of the adult human testicular grafts showed sclerosis. However, in 21.6% of the adult human testicular grafts, spermatogonia were still observed, with increasing sclerosis in time. No significant differences were observed between the two mouse models under evaluation.
  
  
  CONCLUSIONS
  After xenografting human adult testicular tissue to a recipient mouse, spermatogonia were maintained over a period of >195 days. However, in order to prove xenografting as a method for external germ line storage, the transplants should have a more immature developmental stage. Moreover, not only the developmental status of the tissue at the time-point of grafting, but also the structural organisation of the seminiferous epithelium, might influence the development of the testicular tissue.
authors.affiliation: Centre for Reproductive Medicine and Research Centre for Reproduction and Genetics, University Hospital and Medical School, Vrije Universiteit Brussel, Laarbeeklaan 101, B-1090 Brussels, Belgium.
authors.forename: Mieke
authors.initials: M
authors.lastname: Geens
authors.forename: Gert
authors.initials: G
authors.lastname: De Block
authors.forename: Ellen
authors.initials: E
authors.lastname: Goossens
authors.forename: Veerle
authors.initials: V
authors.lastname: Frederickx
authors.forename: André
authors.initials: A
authors.lastname: Van Steirteghem
authors.forename: Herman
authors.initials: H
authors.lastname: Tournaye
mesh_terms: D000818:Animals; D002470:Cell Survival; D006085:Graft Survival; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D016513:Mice, SCID; D012598:Sclerosis; D012671:Seminiferous Tubules / Q000473:pathology; D013093:Spermatogonia / Q000166:cytology* / Q000473:pathology; D013737:Testis / Q000254:growth & development / Q000473:pathology / Q000637:transplantation*; D014183:Transplantation, Heterologous