This strain carries a conditional floxed allele of the Sykb (spleen tyrosine kinase) gene. When crossed with a Cre strain tissue/cell specific excision may be helpful with studies the immune, cardiovascular or skeletal systems.
Alexander Tarakhovsky, The Rockefeller University
In this conditional Sykb (spleen tyrosine kinase) mutant strain, exon 1 has been flanked by loxP sites. When crossed with a Cre recombinase-expressing strain, these mice are useful in eliminating tissue-specific expression of the gene. Homozygous floxed mice are fully viable and fertile.
Homozygous null mice show a variety of defects including high rates of perinatal lethality, abnormal vascular morphology, abnormal osteoclast differentiation, impaired neutrophil phagocytosis, and defects in B cell development.
For example,when bred to a strain carrying Tg(Cr2-cre)3Cgn (Stock No. 006368), Cre recombinase expression in mature B cells results in an altered B cell phenotype.
Exon 1 was flanked by a loxP site and a loxP-flanked neomycin resistance cassette in 129P2/OlaHsd-derived E14.1 embryonic stem (ES) cells. ES cell clones bearing the modified locus were transiently transfected with a Cre expression vector to remove the loxP-flanked neomycin cassette, leaving exon 1 flanked by loxP sites. The resulting chimeric mice were bred to C57BL/6 to establish the mutant colony. Mutant mice were backcrossed to C57BL/6 for approximately seven generations by the donating laboratory (see SNP results below) prior to sending homozygous males with black coat color to The Jackson Laboratory Repository in 2011. Upon arrival, males were used to cryopreserve sperm. To establish the living mouse colony, an aliquot of the frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 living colony at The Jackson Laboratory Repository. One of the 43 markers throughout the genome was found to be segregating with 129. In addition, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. Again, the marker closest to the targeted mutation on chromosome 13 was homozygous for 129P allele-type of the donor embryonic stem cell. These data suggest the mice sent to The Jackson Laboratory Repository were on a C57BL/6N or mixed C57BL/6N;C57BL/6J genetic background.
|Allele Name||targeted mutation 1.2, Alexander Tarakhovsky|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Syk, spleen tyrosine kinase|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||A loxP site was inserted upstream of exon 1 and a floxed neo cassette was inserted downstream of exon 1. Cre mediated recombination removed the neo cassette leaving exon 1 floxed.|
Homozygotes or heterozygotes may be bred to maintain a colony.
When using the Syk conditional mouse strain in a publication, please cite the originating article(s) and include JAX stock #017309 in your Materials and Methods section.