System for inducible expression of cre‐recombinase from the Foxa2 locus in endoderm, notochord, and floor plate

Abstract

We targeted the reverse tetracycline controlled transactivator (rtTA) to the Foxa2 locus (Foxa2 ITA ) to generate a system for regulating Cre-recombinase activity within Foxa2 expression domains, including the endoderm, notochord, and floor plate of early mouse embryos. The use of an internal ribosomal entry site to obtain rtTA expression preserves Foxa2 function of the targeted allele. Cre activity with this system reflects the level of endogenous Foxa2 activity and is also tightly controlled by doxycycline. The location of Cre activity within the broader Foxa2 expression domain can be restricted by altering the timing of doxycycline administration. Isolated floor plate expression can be obtained in this manner. This system will provide a useful tool for manipulating gene expression in endoderm, notochord, and floor plate, all of which are tissues with important structural and patterning functions during embryogenesis. Developmental Dynamics 236:1085-1092, 2007.

A mouse line expressing Foxa2‐driven Cre recombinase in node, notochord, floorplate, and endoderm

“…ITA (IRES tetracycline transactivator; Frank et al, 2007), we failed to observe recombination of the R26R allele in the visceral endoderm between E6.5 and E7.0 (data not shown). At E7.5 b-galactosidase (b-gal) activity was detected in cells anterior to the node and in the anterior endoderm (Fig.…”

Retinoid Signaling in Progenitors Controls Specification and Regeneration of the Urothelium

“…1). To evaluate whether P-cells can produce other urothelial cell types, we used a TM-inducible Foxa2 CreERT line (Frank et al, 2007) in fate mapping experiments. We first examined the specificity of Cre-dependent recombination in the Foxa2 CreERT ; mTmG line by exposing embryos to TM at E11 and analyzing the distribution of the Gfp lineage marker after a short, 24h, chase.…”

Transgenic mouse lines expressing Cre recombinase specifically in posterior notochord and notochord

“…Therefore, their value for left-right developmental studies may be more in the analysis of downstream events and less in probing early aspects. The Foxa2 NFPCre line also may be useful for conditional mutagenesis of genes expressed in floor plate and hindgut beginning at later stages, complementing the recently described inducible system based on Foxa2 regulated reverse tetracycline transactivator (Frank et al, 2007). Together, the lines reported here represent an important addition to the repertoire of tools for precise control of mammalian gene expression.…”