Strain Code 01B74 [Athymic NCr-nu/nu]
Origin and Characteristics
This immunodeficient nude mouse originated from NIH and was originally thought to be a BALB/c congenic. It was later determined that it was not inbred and is, therefore, maintained as an outbred, and is not associated with any stock or strain. The animal does not have a thymus and is therefore immunodeficient and unable to produce T-cells. The NCr athymic outbred stock is the standard athymic model for National Cancer Institute (NCI) studies as well as many pharmaceutical and institutional oncology screening programs. The autosomal recessive nude gene in homozygous ( nu/nu) mice causes the lack of fur and an abnormal thymus. The deficiency in T cell function allows athymic mice to accept and grow xenografts as well as allografts of normal and malignant tissues. Heterozygous (nu/+) animals carry the recessive nude gene on one chromosome only and therefore have a normal thymus triggered immune system. NCI received this mouse in 1988.