Igf1^tm2Ts

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. (J:37969)