Transgenic mice with hematopoietic and lymphoid specific expression of Cre

TLDR

Bacteriophage P1 Cre/loxP systems enable tissue‑specific genome manipulation in mice. The authors generated Cre‑expressing mouse lines targeting hematopoietic tissues via vav elements and lymphoid cells via hCD2 promoter/LCR. Cre activity was evaluated using the R26R‑EYFP reporter, allowing single‑cell level assessment of recombination patterns. The vav promoter induced recombination in all hematopoietic cells, whereas the hCD2 promoter/LCR restricted recombination to T and B cells, with complete deletion in target tissues, demonstrating the utility of these lines for tissue‑specific gene knockouts.

Abstract

Abstract Bacteriophage P1 Cre/loxP based systems can be used to manipulate the genomes of mice in vivo and in vitro, allowing the generation of tissue‐specific conditional mutants. Wehave generated mouse lines expressing Cre recombinase in hematopoietic tissues using the vav regulatory elements, or in lymphoid cells using the hCD2 promoter and locus control region (LCR). The R26R‐EYFP Cre reporter mouse line was used to determine the pattern of Cre expression in each line and enabled the assessment of Cre activity at a single‐cell level. Analysis showed that the vav promoter elements were able to direct Cre‐mediated recombination in all cells of the hematopoietic system. The hCD2 promoter and LCR on the other hand were able to drive Cre‐mediated recombination only in T cells and B cells, but not in other hematopoietic cell types. Furthermore, in the appropriate tissues, deletion of the floxed target was complete in all cells, thereby excluding the possibility of variegated expression of the Cre transgene. Both of these Cre‐transgenic lines will be useful in generating tissue‐specific gene deletions within all the cells of hematopoietic or lymphoid tissues.