Related Experiment Video
Updated: Jul 27, 2026
Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures
Published on: December 22, 2014
Retinal degeneration in the rd mouse in the absence of c-fos
Purpose:
Apoptosis is the final common death pathway of photoreceptors in light-induced retinal degeneration and in several animal models for retinal dystrophy. To date, little is known about gene regulation of apoptosis in the retina. The expression of the immediate early gene c-fos is upregulated concomitant with apoptosis in light-induced photoreceptor degeneration and in the rd mouse, an animal model for inherited retinal degeneration. In a recent study it was shown that c-Fos is essential for light-induced apoptosis of photoreceptors in vivo. To determine whether c-Fos is also involved in the apoptotic pathway of inherited retinal degeneration, rd/rd, c-fos -/- double-mutant mice have been generated.
Methods:
Double-mutant mice (rd/rd, c-fos -/-) were crossbred from c-fos+/- mice and rd/rd mice. Their genotype was determined by polymerase chain reaction analysis of genomic DNA. Wild-type control mice and homozygous rd mice were killed at 2-day intervals from postnatal day (P)9 through P21. Double-mutant mice were killed at postnatal days P9, P11, P13, P15, and P21. To determine levels of apoptosis in the retina, eyes were enucleated and processed for light microscopy and in situ nick-end labeling. Total retinal DNA was extracted from isolated retinas for DNA fragmentation analysis.
Results:
Morphologic, histochemical, and biochemical analyses showed that the time course of apoptosis and the outcome of photoreceptor degeneration in rd/rd, c-fos-/- double-mutant mice was indistinguishable from that in rd mice carrying functional c-fos.
Conclusions:
These data suggest that in contrast to its role in light-induced photoreceptor degeneration, c-Fos is not essential for apoptosis in the rd mouse.
Insights
The immediate early gene c-Fos is not essential for photoreceptor apoptosis in inherited retinal degeneration, unlike its role in light-induced degeneration. This study investigated c-Fos in rd/rd mice, finding no difference in apoptosis without c-Fos.
Area of Science:
- Retinal biology
- Molecular genetics
- Cell death pathways
Background:
- Apoptosis (programmed cell death) is a key mechanism in photoreceptor degeneration.
- The immediate early gene c-fos is upregulated during photoreceptor apoptosis in both light-induced damage and inherited retinal degeneration models.
- Previous research indicated c-Fos is crucial for light-induced photoreceptor apoptosis.
Purpose of the Study:
- To investigate the role of c-Fos in the apoptotic pathway of inherited retinal degeneration.
- To determine if c-Fos is essential for photoreceptor cell death in the rd mouse model.
Main Methods:
- Generation of double-mutant mice (rd/rd, c-fos-/-) by crossbreeding.
- Genotyping via polymerase chain reaction (PCR).
- Analysis of apoptosis using light microscopy, in situ nick-end labeling, and DNA fragmentation assays at various developmental time points.
Main Results:
- Photoreceptor degeneration and apoptosis in rd/rd, c-fos-/- mice were indistinguishable from rd mice with functional c-fos.
- No significant differences in the timing or outcome of cell death were observed between genotypes.
Conclusions:
- c-Fos is not essential for the process of apoptosis in the rd mouse model of inherited retinal degeneration.
- The role of c-Fos in photoreceptor cell death differs between light-induced degeneration and inherited forms.
