STOCK Igf1^tm2Ts/ImJ

Stock number: 003259
Product name: IGF-I^m/m
Research areas: Cancer Research, Endocrine Deficiency Research

Description

These hypomorph Igf1^m/m midi mice exhibit reduced size and IGF-1 serum levels, when compared to wildtype controls. These mice may be useful in studies of cardiac remodeling, obesity and metabolism.

Detailed description

Mice homozygous for the Igf1^tm2Ts mutation (also referred to as the Igf1^m/m midi targeted insertion) are viable and fertile, but are small in size, reaching only approximately 60 - 65% the weight of their wild type siblings. Serum levels of IGF-1 in these mutants is 30% of wild type values. They have no gross histological abnormalities. Arterial blood pressure is higher in Igf1^m/m mice than in wild type controls. The Donating Investigator reports that homozygotes are subfertile but viable, with approximately 50% of homozygous animals dying before weaning.

Development

An entire targeting vector containing a NEO cassette inserted into exon 3 sequence, a thymidine kinase gene and vector sequences was inserted 5' of the endogenous exon 3. The construct was electroporated into 129S7/SvEvBrd-Hprt⁺derived AB1 embryonic stem (ES) cells. ES cells which were carrying this site-specific insertion of the targeting construct rather than homologous recombination were injected into blastocysts. The resulting chimeric animals were tested for germline transmission, and bred to C57BL/6 mice. The mice were then bred to CD-1 outbred mice.

Allele

Symbol: Igf1^tm2Ts
Name: targeted mutation 2, Timothy Stewart
MGI accession ID: MGI:1861704
Generation method: Targeted
Attributes: Hypomorph
Marker symbol: Igf1
Marker name: insulin-like growth factor 1
Chromosome: 10
Strain of origin: 129S7/SvEvBrd-Hprt⁺
Molecular note: Hypomorph. In this allele, a site specific insertion of the entire targeting vector occurred instead of homologous recombination. The construct interrupted exon 3 with a neomycin cassette, with a thymidine kinase gene and vector sequences inserted 5' of the endogenous exon 3. RT-PCR analysis demonstrated that a reduced amount of normal transcript was produced from this allele as well as a mutant transcript, and a low, but detectable level of the protein was present in sera of homozygous mice.