vavCre Transgenic mice: A tool for mutagenesis in hematopoietic and endothelial lineages

Abstract

Cre transgenic mice can be used to delete gene sequences flanked by loxP sites in specific somatic tissues. We have generated vavCre transgenic mice, which can be used to inactivate genes specifically in adult hematopoietic and endothelial cells. In these animals, a Cre transgene is expressed under control of murine vav gene regulatory elements. To assess their usefulness, vavCre transgenic mice were bred with R26R mice, which express a lacZ reporter gene only in cells where Cre-mediated recombination has occurred. VavCre/R26R double-heterozygous offspring were analyzed by beta-galactosidase histochemistry and flow cytometry. VavCre-mediated recombination occurred in most hematopoietic cells of all hematopoietic organs, including the hematopoietic progenitor-rich bone marrow. Recombination also occurred in most endothelial and germ cells, but only rarely in other cell types. The recombination in both hematopoietic and endothelial lineages may partly reflect their putative shared ontogeny and provides a unique tool for simultaneous pan-hematopoietic and endothelial mutagenesis.

Hematopoietic deletion of transferrin receptor 2 in mice leads to a block in erythroid differentiation during iron‐deficient anemia

“…The control animals used for this study were heterozygous for the deleted and floxed Tfr2 alleles.This was done to avoid potential issues due to germ-line transmission of the Vav-Cre 1/2 allele, as previously reported [25]. Previous studies have shown that haplo-insufficiency of TFR2 does not alter systemic iron metabolism and a single allele in the heterozygous animals is sufficient to maintain appropriate iron levels [11,12].…”

“…Previous studies have shown that haplo-insufficiency of TFR2 does not alter systemic iron metabolism and a single allele in the heterozygous animals is sufficient to maintain appropriate iron levels [11,12]. It has been suggested that the Vav-Cre allele could be expressed in the ovaries, hence increasing the chance of germ-line transmission through the females [25,26]. In view of this, only mice generated from a breeding between a Cre 1/2 male were used for the analyses performed in this study.…”

“…The mice used for this study were heterozygous for the floxed and KO allele for TfR2, as previously suggested [26]. This was done to avoid the germ-line transmission of a Tfr2-deleted allele that has been previously reported to occur when using the Vav-Cre transgene [25].…”

“…Tfr2 D/1 /Vav-Cre 1/2 male mice were then bred with Tfr2 f/f female mice to generate Tfr2 D/f /Vav-Cre 2/2 (control) and Tfr2 D/f Vav-Cre 1/2 (KO) mice. Mice with a heterozygous floxed allele were used to avoid germ-line transmission of the Vav-Cre allele [25]. Only mice generated from Cre 1/2 male mice were used; the progeny of the females with the Cre allele were discarded as suggested [25,26].…”

“…Mice with a heterozygous floxed allele were used to avoid germ-line transmission of the Vav-Cre allele [25]. Only mice generated from Cre 1/2 male mice were used; the progeny of the females with the Cre allele were discarded as suggested [25,26]. Control and KO mice were fed a control (iron content: 68 mg/Kg) or an ID (iron content: 2-10 mg/Kg) diet (Specialty Feeds, Glen Forest, Western Australia) from birth.…”