These floxed mutant mice possess loxP sites flanking exon 3 of the myeloid differentiation primary response gene 88 (Myd88). This strain may be useful for generating conditional mutations in applications related to signal transduction, Toll-like receptor signaling and natural killer cells.
T1DR Colony, The Jackson Laboratory
These mice possess loxP sites on either side of exon 3 of the targeted gene. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 3 deleted in the cre-expressing tissue(s).
These myeloid differentiation primary response gene 88 (Myd88) conditional (floxed) mutant mice may be useful in studies of Toll-like receptor signaling and natural killer cells.
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. 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.
A FRT site flanked targeting vector containing neomycin resistance and herpes simplex virus thymidine kinase genes (HSV-TK) and a diphtheria toxin A subunit cassette was utilized in the construction of this mutant. This selection cassette was inserted upstream of exon 3 of the targeted gene, and another loxP site was inserted downstream of exon 3. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to transgenic mice (on a congenic C57BL/6 genetic background) expressing FLPe recombinase under the control of the actin beta (ACTB) promoter to remove the selection cassette. Mice that retained the loxP site flanked exon 3 (and residual single FRT site) were maintained on the C57BL/6J background. Using marker assisted analysis, the T1DR transferred the Myd88 conditional (floxed) mutation from the C57BL/6J background, Stock No. 008888, to the NOD/ShiLtJ (Stock No. 001976) background. At generation N4 all SNP markers tested outside of the congenic region are NOD in origin. In 2011, this strain was transferrred to the repository at generation N6.
|Allele Name||targeted mutation 1, Anthony L DeFranco|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Myd88, myeloid differentiation primary response gene 88|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||Exon 3 was flanked by loxP sites by placing a FRT-flanked neo-cassette with a 3' loxP site upstream of exon 3 with an additional loxP site being placed downstream of exon 3. Founders were crossed with ACTB-FLPe mice to remove the neo selection cassette. Expression levels of Myd88 were unaffected by loxP insertion. Cre-recombination is predicted to excise exon 3 and create a null allele.|
|Mutations Made By|| |
Anthony DeFranco, University of California San Francisco (UCSF)