The generation of cell type specific inducible Cre transgenic mice is the most challenging and limiting part in the development of spatio-temporally controlled knockout mouse models. Here we report the generation and characterization of a B lymphocyte-specific tamoxifen-inducible Cre transgenic mouse strain, LC-1-hCD19-CreERT2. We utilized the human CD19 promoter for expression of the tamoxifen-inducible Cre recombinase (CreERT2) gene, embedded in genomic sequences previously reported to give minimal position effects after transgenesis. Cre recombinase activity was evaluated by cross-breeding the LC-1-hCD19-CreERT2strain with a strain containing a floxed gene widely expressed in the hematopoietic system. Cre activity was only detected in the presence of tamoxifen and was restricted to B lymphocytes. The efficacy of recombination ranged from 27 to 61% in the hemizygous and homozygous mice, respectively. In conclusion, the LC-1-hCD19-CreERT2strain is a powerful tool to study gene function specifically in B lymphocytes at any chosen time point in the lifecycle of the mouse.

B cells, Cre recombinase, CreER, Somatic mutagenesis, T2, Tamoxifen,
Genesis: The Journal of Genetics and Development
Erasmus MC: University Medical Center Rotterdam

Boross, P, Breukel, C, van Loo, P.F, van der Kaa, J, Claassens, J.W, Bujard, H, … Verbeek, J.S. (2009). Highly B lymphocyte-specific tamoxifen inducible transgene expression of CreERT2 by using the LC-1 locus BAC vector. Genesis: The Journal of Genetics and Development, 47(11), 729–735. doi:10.1002/dvg.20549