Z/EG, a double reporter mouse line that expresses enhanced green fluorescent protein upon cre‐mediated excision

Abstract

The Cre/loxP system has become an important tool in designing postintegrational switch mechanisms for transgenes in mice. The power and spectrum of application of this system depends on transgenic mouse lines that provide Cre recombinase activity with a defined cell type-, tissue-, or developmental stage-specificity. We have developed a novel mouse line that acts as a Cre reporter. The mice, designated Z/EG (lacZ/EGFP), express lacZ throughout embryonic development and adult stages. Cre excision, however, removes the lacZ gene, which activates expression of the second reporter, enhanced green fluorescent protein. We have found that the double-reporter Z/EG line is able to indicate the occurrence of Cre excision from early embryonic to adult lineages. The advantage of the Z/EG line is that Cre-mediated excision can be monitored in live samples and that live cells with Cre-mediated excision can be isolated using a single-step FACS. It will be a valuable reagent for the increasing number of investigators taking advantage of the powerful tools provided by the Cre/loxP site-specific recombinase system.

PTP1B and SHP2 in POMC neurons reciprocally regulate energy balance in mice

“…DNA was extracted from a drop of blood from each experimental animal to check for the occurrence of spurious germline deletion using the following primers: Ptpn1 Δ/Δ forward 5′-GTGGTGCCTGCAAGAGAACTGAC, reverse 5′-GAAATG-GCTCACTCCTACTGG; Ptpn11 Δ/Δ forward 5′-TAGCTGCTTTAACCCTCT-GTGT, reverse 5′-AATTGCGGCTTCTTGTCCT; IL-2 primers were used as an internal control (Jax primers forward 5′-CTAGGCCACAGAATT-GAAAGATCT-3′; reverse 5′-GTAGGTGGAAATTCTAGCATCATCC-3′); Z/EG reporter mice (The Jackson Laboratory, stock 003920; ref. 102) were genotyped using the following GFP primers: forward 5′-TCATGGCCGA-CAAGCAGAAGAACG-3′, reverse 5′-CGGCGGCGGTCACGAACT-3′. All experiments used Ptpn1 loxP/loxP and Ptpn11 loxP/loxP mice that were originally on a mixed 129Sv/J × C57BL/6 background but were backcrossed at least 3 generations onto C57BL/6 prior to mating with POMC-Cre mice (gift from B. Lowell, Beth Israel Deaconess Medical Center, Boston, Massachusetts, and J. Elmquist, University of Texas Southwestern Medical Center, Dallas).…”

β1 Integrins in Radial Glia But Not in Migrating Neurons Are Essential for the Formation of Cell Layers in the Cerebral Cortex

“…2), LacZ expression at embryonic ages was more difficult to visualize because of the relatively weak expression of the LacZ transgene from the Rosa26 locus. Therefore, to analyze the extent of CRE-mediated recombination during embryonic ages, we crossed the Nex-CRE mice with the Z/EG reporter mouse line, which expresses high levels of GFP upon CRE-mediated recombination (Novak et al, 2000). Analysis of whole mounts revealed a recombination pattern similar to that observed with the LacZ reporter ( Fig.…”

“…Genotyping was performed as described previously (Graus-Porta et al, 2001). Itga3-null mice and CRE activity reporter mice Rosa26lacZ-loxP and Z/EG have been described previously (Kreidberg et al, 1996;Novak et al, 2000).…”

Olfactory epithelium progenitors: insights from transgenic mice and in vitro biology

“…If OE-based Nestin-expressing cells are RGLPs, then lineage tracing of nestin transgene-activating cells, similar to that performed in the CNS (Tronche et al 1999) should reveal this. By combining Nestin-Cre mice with flox'd reporters that initiate YFP expression upon excision (Novak et al 2000;Srinivas et al 2001), all progeny derived from cells employing CNS nestin-specific enhancers should become YFP+ (Joyner and Zervas 2006). We can clearly detect nestin protein expression in the E10.5 OP (Fig.…”