Related Experiment Video
Updated: Aug 20, 2026
A Method for Lineage Tracing of Corneal Cells Using Multi-color Fluorescent Reporter Mice
Published on: December 18, 2015
Targeted expression of Cre recombinase to cone photoreceptors in transgenic mice
Yun-Zheng Le1, John D Ash, Muayyad R Al-Ubaidi
1Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, USA. Yun-Le@ouhsc.edu
Purpose:
Disruption of widely expressed essential genes in mice often leads to embryonic or neonatal lethality. To circumvent this problem and dissect gene functions in the cone photoreceptors, we elected to generate cone photoreceptor specific cre transgenic mice.
Methods:
Transgenic mice expressing Cre recombinase directed by the human red/green pigment (HRGP) gene promoter were generated. Candidate Cre-expressing lines were identified with RT-PCR. Cre-expressing mice were characterized with immunocytochemical assays and functional studies using a Cre activatable lacZ reporter mouse strain (R26R). Cone distribution was determined by immunohistochemistry and retinal function was measured by electroretinography (ERG) on six month old HRGP-cre mice.
Results:
RT-PCR analysis suggested that several transgenic lines expressed cre mRNA in the retina. Beta-galactosidase staining on retinal flat mounts and sections from F1 mice derived from the HRGP-cre and R26R reporter mice suggested that two mouse strains were capable of carrying out efficient Cre mediated recombination in cone photoreceptors. Immunocytochemical staining of retinal sections demonstrated that Cre expression was localized to cone photoreceptors. Cone distribution and cone ERG analysis suggested that cone photoreceptors were normal in adult HRGP-cre mice.
Conclusions:
We have generated transgenic mice that efficiently express Cre recombinase in cone photoreceptor cells. The adult transgenic mice have normal cone distribution and function. They can be used in conditional knockout experiments for gene function studies in cone photoreceptors.
Insights
Researchers created cone photoreceptor-specific Cre transgenic mice to study gene function. These mice exhibit normal cone distribution and function, enabling conditional knockout studies in these vital retinal cells.
Area of Science:
- Genetics and Molecular Biology
- Ophthalmology and Vision Science
- Developmental Biology
Background:
- Essential gene disruption in mice often causes embryonic lethality, hindering functional studies.
- Cone photoreceptors are critical for color vision and visual acuity.
- A method to specifically target gene function in cone photoreceptors is needed.
Purpose of the Study:
- To generate cone photoreceptor-specific Cre transgenic mice.
- To enable conditional gene knockout studies in cone photoreceptors.
- To circumvent embryonic lethality associated with essential gene disruption.
Main Methods:
- Generated transgenic mice using the human red/green pigment (HRGP) gene promoter to drive Cre recombinase expression.
- Identified Cre-expressing lines via RT-PCR and characterized them using immunocytochemistry.
- Utilized a Cre-activatable lacZ reporter (R26R) mouse strain to confirm Cre-mediated recombination in cone photoreceptors. Assessed cone distribution and retinal function via electroretinography (ERG).
Main Results:
- Two transgenic mouse strains demonstrated efficient Cre-mediated recombination specifically in cone photoreceptors.
- Immunocytochemistry confirmed Cre expression localized to cone photoreceptors.
- Cone distribution and ERG analyses showed normal cone photoreceptor structure and function in adult mice.
Conclusions:
- Successfully generated transgenic mice with efficient Cre recombinase expression in cone photoreceptors.
- These mice possess normal cone distribution and function in adulthood.
- The developed HRGP-cre mouse model is suitable for conditional knockout studies to investigate gene functions in cone photoreceptors.
