antoun nabhan anabhanattglobalnet _4805122_alt contenttype textplain charsetusascii formatflowed well transhumanists interested one crossspecies testes transplant successful 1900 14 august 02 newscientistcom news service testis tissue goats pigs grafted onto backs mice shown produce normal sperm capable fertilising eggs first time testis tissue distant species produced mature sperm grafted mice might work primates even humans claims ina dobrinski university pennsylvania one coauthors study technique could used preserve reproductive potential male cancer patients undergo therapies would destroy ability make sperm men often freeze sperm samples receiving chemotherapy young boys produce mature sperm works humans technique would allow testis tissue grafted boys mature produce sperm infectious particles mouse grafting technique also advantage another option preserving fertility testicular transplants involve reimplanting preserved germ cells testes cancer remission grafting approach would eliminate possibility passing cancer cells back patient says reproductive biologist michael griswold washington state university however possible grafting procedure could introduce mousederived infectious particles human embryos making scientists wary idea would much hesitate say something says reproductive biologist roger gosden east virginia medical school castrated mice study dobrinski colleagues placed small pieces testis tissue newborn goats pigs skin backs castrated mice two four weeks later found half 477 grafts survived producing normallooking goat pig sperm injected graftderived sperm directly eggs saw clear signs fertilisation indicating sperm function normally researchers also found procedure worked well testis tissue refrigerated two days frozen several weeks gosden tried transplanting human testes tissue mice successful however dobrinski believes technique could soon used preserve germ lines endangered species including rare animals usually die captivity reaching sexual maturity think thats real application says adds mice human testis tissue grafts would also useful scientists want test effects toxic substances new contraceptives human sperm production journal reference nature vol 418 p 778 robin orwant _4805122_alt contenttype texthtml charsetusascii well transhumanists interested one httpwwwnewscientistcomnewsnewsjspidns99992677 crossspecies testes transplant successful 1900 14 august 02 newscientistcom news service testis tissue goats pigs grafted onto backs mice shown produce normal sperm capable fertilising eggs first time testis tissue distant species produced mature sperm grafted mice might work primates even humans claims ina dobrinski university pennsylvania one coauthors study technique could used preserve reproductive potential male cancer patients undergo therapies would destroy ability make sperm men often freeze sperm samples receiving chemotherapy young boys produce mature sperm works humans technique would allow testis tissue grafted boys mature produce sperm infectious particles mouse grafting technique also advantage another option preserving fertility testicular transplants involve reimplanting preserved germ cells testes cancer remission grafting approach would eliminate possibility passing cancer cells back patient says reproductive biologist michael griswold washington state university however possible grafting procedure could introduce mousederived infectious particles human embryos making scientists wary idea would much hesitate say something says reproductive biologist roger gosden east virginia medical school castrated mice study dobrinski colleagues placed small pieces testis tissue newborn goats pigs skin backs castrated mice two four weeks later found half 477 grafts survived producing normallooking goat pig sperm injected graftderived sperm directly eggs saw clear signs fertilisation indicating sperm function normally researchers also found procedure worked well testis tissue refrigerated two days frozen several weeks gosden tried transplanting human testes tissue mice successful however dobrinski believes technique could soon used preserve germ lines endangered species including rare animals usually die captivity reaching sexual maturity think thats real application says adds mice human testis tissue grafts would also useful scientists want test effects toxic substances new contraceptives human sperm production journal reference nature vol 418 p 778 robin orwant _4805122_alt httpxentcommailmanlistinfofork thu 15 aug 2002 105013 0700 whats species