Their outbred nature, however, makes them more vigorous than either NU/J or B6-nudes, so they may be able to withstand more invasive or severe experimental manipulation. In contrast, outbred J:NU nudes may exhibit more variable tumor growth because they are genetically heterogeneous. Therefore, they are likely to support more consistent tumor growth. Being inbred and congenic, respectively, NU/J and B6-nudes are genetically homogeneous. JAX maintains live colonies of three different nude strains: NU/J ( 002019) inbred mice, B6-nude ( 000819) congenic mice, and J:NU ( 007850) outbred nudes. They are also poor hosts for slow-growing human or mouse primary tumor cells or heterogeneous tumor fragments. However, because nude mice still have B cell and robust NK cell responses, they are not suitable hosts for blood-borne cancers, such as leukemias or lymphomas. The hairless phenotype also makes following fluorescently labeled cells by whole-body imaging very easy. Because they are hairless, they don’t have to be shaved or depilated to evaluate the growth of a subcutaneous tumor. In general, nude mice make ideal hosts for established, rapidly growing tumor cell lines. Matching your answers to these questions to the characteristics of the mice described in the Comprehensive Immunodeficient Suite should considerably narrow your host choices. How long do you need the mice to remain engrafted?.Where will you engraft the tumor- e.g., subcutaneously or orthotopically- and how will you evaluate its growth?.

What type of tumor do you want to engraft- e.g., an established cell line, a blood-borne tumor, or a slow-growing primary tumor?.Choosing a tumor cell hostĬhoosing the best host for a tumor study from among these strains depends on several factors, including: Additionally, because they both have NOD/ShiLtJ genetic backgrounds, they are hemolytic complement-deficient and carry alleles that adversely affect macrophage and dendritic cell functions. These mice are B, T and NK cell deficient. Among these mice are our NSG and NRG mice, which carry a specific mutation in the interleukin 2 receptor gamma subunit gene ( Il2rg tm1Wjl) in combination with the Prkdc scid and Rag1 tm1Mom, respectively. Mice that carry either the Rag1 tm1Mom or Rag2 tm1.1Cgn mutations have very similar, if not identical, phenotypes.įinally, “higher-order, multigenic” immunodeficient mice are constructed from either Prkdc scid or Rag-deficient mice, and carry additional immunodeficiency-enhancing mutations. Like the Prkdc gene, both Rag1 and Rag2 are required for somatic recombination of TCR and Ig genes, and the absence of either gene results in T and B cell deficiency. “ Rag-deficient” mice are mice that fail to express functional Rag1 or Rag2 proteins. In the absence of Prkdc protein, TCR and Ig genes cannot rearrange, resulting in mice that are both T and B cell deficient. The gene Prkdc encodes the catalytic subunit of DNA-dependent protein kinase that is required for DNA repair and for sealing the double-stranded DNA breaks that occur during somatic recombination of T cell receptor (TCR) and immunoglobulin (Ig) genes. “ Scid” mice are homozygous for the Prkdc scid mutation. Because the thymus fails to form, there is no place for CD4 + and CD8 + T cells to differentiate and mature, making nude homozygotes T cell-deficient. In its absence, mice are both hairless and athymic. Foxn1 encodes a transcription factor required for both hair follicle and thymic development. Briefly, “nude” mice are homozygous for the Foxn1 nu, or “nude,” mutation. “Higher-order, multigenic” immunodeficient miceĪ JAX Notes article thoroughly describes these offerings.JAX distributes a variety of immunodeficient strains that can be divided into four main categories: It’s a straightforward question with a not-so-straightforward answer! Four classes of immunodeficient mice

What are the different kinds of scid