B6.129(Cg)-Tg(CAG-EGFP)D4Nagy/KnwJ

Stock number: 018979
Research areas: Research Tools

Description

These mice carry a transgene containing the Enhanced Green Fluorescent Protein driven by chicken beta-actin promoter and CMV intermediate early enhancer, which is integrated on the X chromosome. This strain may be a source of fluorescently marked cells/tissues.

Detailed description

This transgenic strain carries the Enhanced Green Fluorescent Protein (Clontech) driven by chicken beta-actin promoter and CMV intermediate early enhancer. The transgene was found to have integrated on the X chromosome. Mice of this strain, and cells derived from them, can be distinguished from wildtype on the basis of fluorescence. Transgene expression is seen as early as ~embryonic day 2.75, as morula stage embryos begin to compact. Expression of EGFP is spatiotemporally widespread, though levels differ between different lineages (e.g., expression is slightly higher in the heart). As the transgene is located on the X chromosome, transgenic males will exclusively transmit the EGFP transgene to their female offspring, providing the basis for a non-invasive sexing assay based on green fluorescence. The Donating Investigator reports that female homozygotes are not viable on this C57BL/6J congenic background. Hemizygous females on the congenic C57BL/6J background are viable and fertile. These mice may be useful for sex discrimination prior to overt sexual dimorphism (embryonic day 12.5), monitoring X-inactivation, and may be a source of fluorescently marked cells/tissues.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. This is the case for the strain above. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

Development

A transgenic construct containing an Enhanced Green Fluorescent Protein gene under the control of the a chicken beta actin promoter coupled with the cytomegalovirus (CMV) immediate early enhancer, was introduced into (129X1/SvJ x 129S1/Sv)F1-derived R1 embryonic stem (ES) cells. ES cells containing the construct were aggregated with ICR morulae and the resulting chimeric males were bred with ICR females for germline transmission. The transgenic offspring on the mixed background were intercrossed to generate homozygotes. Mice derived from founder line D4/XEGFP were sent to The Jackson Laboratory in 1998 and used to establish the colony on a mixed genetic background. The mice were then backcrossed to C57BL/6J for 8 to 10 generations. This transgene has been found to have integrated on the X chromosome.

Allele

Symbol: Tg(CAG-EGFP)D4Nagy
Name: transgene insertion D4, Andras Nagy
MGI accession ID: MGI:3055027
Generation method: Transgenic
Attributes: Reporter
Marker symbol: Tg(CAG-EGFP)D4Nagy
Marker name: transgene insertion D4, Andras Nagy
Chromosome: X
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: Integration is on the X Chromosome. The transgene is expressed in a spatiotemporally ubiquitous manner, with expression being slightly higher in heart than in other tissues. Transgene expression is seen as early as ~E2.75.
Molecular note: The transgene contains the enhanced Green Fluorescent Protein driven by chicken beta-actin promoter and CMV intermediate early enhancer. Transgenic mice were generated by embryonic stem (ES) cell-mediated transgenesis. The construct was electroporated into R1 ES cells and random integration occurred on the X chromosome just distal of Timp and Syn1.
General note: Transgene expression is seen as fluorescence under exposure to a 488 nm light source. In transgenic mice the reporter may be detected as early as ~E2.75, as morula stage embryos begin to compact. Expression of GFP is spatiotemporally ubiquitous, though levels differ between different lineages (e.g., expression is slightly higher in the heart).

No discernible phenotype, other than green fluorescence, has been observed in any mice carrying this transgene.