knockout mouse

(redirected from Knock-out mice)

mouse

 [mows]
a small rodent, various species of which are used in laboratory experiments.
1. a small loose body.
2. a computer pointing device.
joint mouse a movable fragment of synovial membrane, cartilage, or other body within a joint; usually associated with degenerative osteoarthritis and osteochondritis dissecans.
knockout mouse a mouse that has had a specific gene artificially deleted from its genome.
nude mouse a mouse homozygous for the nu gene; these mice are hairless, lack a thymus, and thus lack T lymphocytes.
peritoneal mouse a free body in the peritoneal cavity, probably a small detached mass or omentum, sometimes visible radiographically.
SCID mouse (severe combined immunodeficiency) a strain of mice lacking in T and B lymphocytes and immunoglobulins, either from inbreeding with an autosomal recessive trait or from genetic engineering, used as a model for studies of the immune system.

knockout mouse

a mouse from whose genome a single gene has been artificially deleted.

Experimental animals lacking specific genes have become valuable research tools in many branches of medicine, including genetics, physiology, pharmacology, immunology, cell biology, and oncology. A transgenic animal is one into whose genome a foreign gene, constructed by recombinant DNA technology, has been deliberately inserted. Placement of the inserted gene at a specific locus in the genome is made possible by incorporating it in a vector in which it is flanked by DNA sequences unique to the target site. The artificial genetic material is introduced into an embryo, which then develops into a chimera whose tissues contain both normal cells and cells containing the transgene. Matings among such animals yield some offspring that are homozygous for the transgene. If the inserted gene is a nonfunctional (null) allele, it deletes or "knocks out" the normal, wild allele. Not only is the deleted gene not expressed, but the offspring of matings among homozygous individuals constitute a pure strain, all of whose members lack the gene. Although theoretically any animal could be subjected to the knockout technique, mice have been used almost exclusively. Mice are small and easily maintained and they reproduce rapidly and have a short life span. In addition, mouse and human genomes are strikingly similar, with about 75% correspondence of genes. That knockout mice lacking a wide variety of genes are often phenotypically normal indicates that the mouse genome, like that of human beings, often has sufficient redundancy to compensate for a single missing pair of alleles. Knockout mice lacking the p53 tumor suppressor gene are used in studies of carcinogenesis, and those lacking the gene for the low-density lipoprotein (LDL) receptor constitute an animal model of human familial hypercholesterolemia. Knockout mice have proved valuable in revealing the functions of genes for which mutant strains were not previously available.

A genetically engineered mouse created by gene targeting—targeted gene disruption—in which a specific gene is deleted or inactivated by homologous recombination, to study the effects of its absence. Knockout mouse models of human disease have been created for atherosclerosis, cancer, cystic fibrosis, etc.

knock·out mouse

(nok'owt mows)
A mouse from whose genome a single gene has been artificially deleted.
References in periodicals archive ?
Historically, ApoE knock-out mice were the first animal model of atherosclerosis established using gene technology methods.
Myo3a and Myo3b double knock-out mice are profoundly deaf, demonstrating that class III myosins play redundant roles in hearing function [41].
Extensive research on the knock-out mice model market has brought to light that knock-out mice models are available with a broad price range and there are many factors that impact the pricing of knockout mice.
The scientists now intend to use PLS3 knock-out mice, where the PLS3 gene has been removed, in the search for the disease-causing mechanism involved.
Measurement of Serum Sclerostin by an Enzyme-Linked Sandwich Assay in Sost Wild type and Knock-out Mice
For example, [beta]2 nAChR knock-out mice no longer express the [beta]2 nAChR subunit protein and, therefore, do not produce any nAChR subtypes that contain the [beta]2 subunit (e.g., [alpha]4[beta]2 nAChRs).
Transgenic mice lacking PPAR[Alpha] (PPAR[Alpha] knock-out mice) do not elicit hepatic peroxisome proliferation, replicative DNA synthesis, or liver enlargement with exposure to peroxisome proliferators (31).
To verify reactivity against apo B-100 and apo B-48 in the assay, we measured the apo B concentrations in chow-fed LDL receptor knock-out mice [20] and apo E knock-out mice [19] (both murine lines from Jackson Labs., Bar Harbor, ME).
Some knock-out mice produced by the researchers had a strange greasy fur, and they had difficulties being weaned from their mother.
Knock-out mice are currently produced by growing embryo-derived pluripotent stem cells in culture, creating targeted mutations in them and then transplanting them into preimplantation mouse embryos to produce a chimera that comprises normal recipient lineages as well as lineages derived from the mutant cells.
The animals in which the CB1 receptor had been switched off (the knock-out mice) clearly differed from their kind.
They used the best animal model available to look at endometrial cancer - the PTEN knock-out mice.