Systemic recombination in a novel Cre transgenic line, CAG-Cre C57BL/6N mouse

概要

The Cre/loxP system mediate site-specific DNA recombination and are being increasingly utilized to study gene function in vivo(1). In mammalian cells, DNA recombination by Cre recombinase is feasible for temporally and spatially controlled gene ablation. To reveal various molecular mechanisms of living animals by means of the system, precise assessment of the strain including expression profile of the transgene and genetic background is essential. C57BL/6 mice are one of the most commonly used inbred strains in laboratory research. The strain is subdivided into multiple substrains (eg, C57BL/J and C57BL/N) that accumulated significant genetic variations causing differences in their survival and disease phenotypes including cardiovascular, metabolic, or neurologic symptoms (2-4). There have not been established CAG-Cre transgenic line with C57BL/N genetic background yet, therefore we established a novel Cre expression line on the C57BL/6N background, which express Cre recombinase under the control of the CAG promoter. We mated the mice with R26GRR reporter mice, which express GFP before and tdsRed after Cre-mediated recombination, to validate the recombination efficiency, and found that the CAG-Cre mouse possessed sufficient Cre recombinase activity in a systemic manner (5). The activity was observed at birth and maintained in adult. Here, we describe a novel CAG-Cre mice on the C57BL/6N background contributes a unique resource to experimental validity and reproducibility.