Moreover, the absence of functioning T cells prevents nude mice from rejecting not only allografts, but they cannot even reject xenografts that is, grafts of tissue from another species.
![siberian mouse girl siberian mouse girl](https://d3t3ozftmdmh3i.cloudfront.net/production/podcast_uploaded400/5584828/5584828-1589751506079-ff80059b1d46c.jpg)
Most strains of nude mice are slightly "leaky" and do have a few T cells, especially as they age. For this reason, nude mice are less popular in research today, since knockout mice with more complete defects in the immune system have been constructed (e.g. Nude mice have a spontaneous deletion in the FOXN1 gene. (Humans with mutations in FOXN1 also are athymic and immune deficient. ) Mice with a targeted deletion in the FOXN1 ("knockout" mice) also show the "nude" phenotype. Since nude females have underdeveloped mammary glands and are unable to effectively nurse their young, nude males are bred with heterozygous females. The life span of nude mice is normally 6 months to a year. In controlled, germ free environments and with antibiotic treatments found in many laboratories that routinely use nude mice, they can live almost as long as normal mice (18 months to two years).
![siberian mouse girl siberian mouse girl](https://gocool.ru/uploads/images/5/c/5/5c54c1483aa683dbbbf6e9ff1440574a.jpg)
“I want to go home, Mom,” she pleads into the phone after a particularly difficult day. Vall and her roommate Madlyn rush from interview to interview, only to be rejected. “They said they’ll pay us $8,000 even if we don’t get work,” says Madlyn, who is so unhappy she gobbles candy, blatantly disregarding a clause of her contract that says the agency can send her home without pay if she gains one centimeter on her hips or waist.