C3Ou.129S2-Rb1^tm1Tyj/J

Stock number: 002546
Product name: Rb^x3t
Research areas: Apoptosis Research, Cancer Research, Developmental Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Mouse/Human Gene Homologs

Description

Homozygous Rb1 knock-out mice exhibit prenatal lethality while heterozygous mice develop pituitary tumors.

Detailed description

Mice homozygous for this targeted mutation die in utero, apparently from a failure to produce erythrocytes in the liver, demonstrating that the endogenous gene is essential for normal development. Heterozygous mice, which are analogous to human carrier individuals, do not develop retinal tumors, but do develop pituitary tumors by 8 months of age.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. This is the case for this strain. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

Development

This mutant strain was developed in the laboratory of Dr. Tyler Jacks at the Center for Cancer Research at the Massachusetts Institute of Technology. The 129-derived D3 ES cell line was used. This strain was made by backcrossing mutant mice to C3H/HeOuJ. As of February 1996 this strain had been backcrossed five times (N5). In 1999 it had been backcrossed to C3H/HeOuJ for 10 generations.

Allele

Symbol: Rb1^tm1Tyj
Name: targeted mutation 1, Tyler Jacks
MGI accession ID: MGI:1857242
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Rb1
Marker name: RB transcriptional corepressor 1
Chromosome: 14
Strain of origin: 129S2/SvPas
Molecular note: A PGK-neomycin resistance cassette replaced part of intron 3 and introduced three nucleotide changes into exon 3, creating two termination codons and a new PstI site. The authors predict translation of a truncated protein by the mutant allele. Immunoblot analysis of E12.5 brain did not detect full length RB1 protein in homozygous mice.
General note: This is one of several targeted null mutations of Rb1 that have been created. Results appear to be similar for all the mutations (J:2498, J:2511, J:2516). Heterozygotes for the mutations show no predisposition to retinoblastoma. Homozygotes die in utero with neuronal and hematopoietic system abnormalities. Transfer of a human RB1 mini-transgene into the mutant mice corrects the defects (J:2516). On the other hand, transfer of the human gene into mice with a normal Rb1 genotype, causing overexpression of the gene product, produces mice dwarfed in proportion to the number of extra RB1 copies they carry (J:15042). Homozygous Rb^1tm1Tyj mutant mice given a transgene producing low levels of Rb1 product survive to birth, but die at that stage due to failure of myogenesis. Myoblasts undergo massive apoptosis, and surviving cells do not undergo terminal differentiation (J:37145).