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.
