Lin28b (lin-28 homolog B (C. elegans)) has been implicated with human growth and glucose metabolism.
Exon 2 of the Lin28b mouse gene, encoding the functional cold shock domain, was deleted in this targeted mutation strain. The weights of homozygous embryos and their placentae at E18.5 are comparable to those of heterozygotes, suggesting the gene is dispensible for embryonic growth. Males show postnatal dwarfism and organ weights are reduced in relative proportion to total body weight. Females show no postnatal growth defects.
A targeting vector was used to introduce loxP sites on either side of exon 2 (encoding the functional cold shock domain) and an FRT-flanked PGK-neomycin cassette to intron 2 via homologous recombination in (C57BL/6 x 129S4/SvJae)F1-derived v6.5 embryonic stem (ES) cells. Chimeric males were bred to BALB/c females, then the line was backcrossed to C57BL/6 for 7 generations. Mice were crossed with FVB background Ddx4-cre mice (see Stock No. 006954) to excise the floxed region. This strain was then backcrossed to FVB for 5 generations before being backcrossed to C57BL/6J for more than 6 generations by the donating laboratory.
|Allele Name||targeted mutation 1.1, George Q Daley|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Lin28b, lin-28 homolog B (C. elegans)|
|Strain of Origin||(C57BL/6 x 129S4/SvJae)F1|
|Molecular Note||A loxP site was inserted upstream of exon 2. An FRT-flanked neomycin resistance cassette with a 5' loxP site was inserted downstream of exon 2. Cre-mediated recombination removed exon 2. Western blot analysis confirmed the absence of protein expression in embryonic stem cells.|
Heterozgyotes are viable and fertile.
When using the B6.Cg-Lin28btm1.1Gqda/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #023917 in your Materials and Methods section.