STOCK Lin28a^tm2.1Gqda Lin28b^tm2.1Gqda/J

Stock number: 023915
Research areas: Research Tools

Description

Exon 2 of both the mouse Lin28a and Lin28b genes are flanked by loxP sites in this targeted mutant strain. Cre excision of each floxed region results in a knockout which may be useful in studies of growth and metabolism.

Detailed description

Human LIN28A (lin-28 homolog A (C. elegans)) and LIN28B (lin-28 homolog A (C. elegans)) genes have been implicated in growth and glucose metabolism.

In this targeted mutation strain, the exon 2 sequences in both Lin28a and Lin28b have been flanked by loxP sites. Cre excision of the floxed segments creates knockout alleles. Mice homozygous for both floxed alleles are viable and fertile.

Mice homozygous for a knockout of both genes (produced by crosses with germline cre mice, e.g. Stock No. 006954) show developmental delays and embryonic lethality.

Development

Exon 2 of each gene was flanked by loxP sites and an FRT-flanked neomycin cassette was introduced to intron 2 through homologous recombination in (C57BL/6 x 129S4/SvJae)F1-derived v6.5 embryonic stem (ES) cells. Chimeric animals were bred with BALB/c animals then then the line was backcrossed to C57BL/6 for 6 generations (see SNP note below). The neomycin cassettes were excised via a Flp recombinase.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Three of the 27 markers throughout the genome were segregating suggested an incomplete backcross. Also, 1 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic.

Allele

Symbol: Lin28b^tm2.1Gqda
Name: targeted mutation 2.1, George Q Daley
MGI accession ID: MGI:5520057
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Lin28b
Marker name: lin-28 homolog B (C. elegans)
Chromosome: 10
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Molecular note: A loxP site was inserted upstream of exon 2. An FRT flanked neo cassette with a 5' loxP site was inserted downstream of exon 2 via homologous recombination. FLP-mediated recombination removed the neomycin cassette.
General note: The targeting vector used to generate this allele was co-injected with the targeting vector used to generate Lin28a^tm2.1Gqda.

Allele

Symbol: Lin28a^tm2.1Gqda
Name: targeted mutation 2.1, George Q Daley
MGI accession ID: MGI:5520055
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Lin28a
Marker name: lin-28 homolog A (C. elegans)
Chromosome: 4
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Molecular note: A loxP site was inserted upstream of exon 2. An FRT flanked neo cassette with a 5' loxP site was inserted downstream of exon 2 via homologous recombination. FLP-mediated recombination removed the neomycin cassette.
General note: The targeting vector used to generate this allele was co-injected with the targeting vector used to generate Lin28b^tm2.1Gqda.