title: Donor-host involvement in immature rat testis xenografting into nude mouse hosts.
abstract: Immature testicular tissue of a wide variety of mammalian species continues growth and maturation when ectopically grafted under the dorsal skin of adult nude mouse recipients. Tissues from most donor species fully mature, exhibiting complete spermatogenesis within months. The connection to the recipient's vascular system is mandatory for graft development, and failure of vascularization leads to necrosis in the grafted tissue. In the present study, we analyze to what extent 1) the xenografted immature donor tissue and 2) the recipient's cells and tissues contribute to the functional recovery of a "testicular xenograft." We address whether recipient cells migrate into the testicular parenchyma and whether the circulatory connection between the donor testicular tissue and the recipient is established by ingrowing host or outgrowing donor blood vessels. Although this issue has been repeatedly discussed in previous xenografting studies, so far it has not been possible to unequivocally distinguish between donor and recipient tissues and thus to identify the mechanisms by which the circulatory connection is established. To facilitate the distinction of donor and recipient tissues, herein we used immature green fluorescent protein-positive rat testes as donor tissues and adult nude mice as graft recipients. At the time of graft recovery, donor tissues could be easily identified by the GFP expression in these tissues, allowing us to distinguish donor- and recipient-derived blood vessels. We conclude that the circulatory connection between graft and host is established by a combination of outgrowing small capillaries from the donor tissue and formation of larger vessels by the host, which connect the graft to subcutaneous blood vessels.
authors.affiliation: Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Münster, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schlatt
authors.forename: Birgit
authors.initials: B
authors.lastname: Westernströer
authors.forename: Kathrin
authors.initials: K
authors.lastname: Gassei
authors.forename: Jens
authors.initials: J
authors.lastname: Ehmcke
mesh_terms: D000818:Animals; D002465:Cell Movement; D006085:Graft Survival / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000502:physiology*; D051381:Rats; D055647:Rats, Transgenic; D020127:Recovery of Function; D013045:Species Specificity; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000098:blood supply / Q000254:growth & development* / Q000378:metabolism / Q000637:transplantation; D014183:Transplantation, Heterologous
chemical_list: D049452:Green Fluorescent Proteins