| First Author | Pennesi ME | Year | 2003 |
| Journal | J Neurosci | Volume | 23 |
| Issue | 2 | Pages | 453-61 |
| PubMed ID | 12533605 | Mgi Jnum | J:81741 |
| Mgi Id | MGI:2449893 | Doi | 10.1523/JNEUROSCI.23-02-00453.2003 |
| Citation | Pennesi ME, et al. (2003) BETA2/NeuroD1 null mice: a new model for transcription factor-dependent photoreceptor degeneration. J Neurosci 23(2):453-61 |
| abstractText | BETA2/NeuroD1 is a basic helix-loop-helix transcription factor that is expressed widely throughout the developing nervous system. Previous studies have shown that BETA2/NeuroD1 influences the fate of retinal cells in culture. To analyze the effect of BETA2/NeuroD1 on the structure and function of the retina, we examined a line of BETA2/NeuroD1 knock-out mice that survives until adulthood. At 2-3 months of age, homozygous null mice showed a 50% reduction in rod-driven electroretinograms (ERGs) and a 65% reduction in cone-driven ERGs. ERGs measured from knock-out mice that were >9 months of age were undetectable. At 2-3 months, the number of photoreceptors in the outer nuclear layer was reduced by 50%. In addition, electron microscopy showed that the surviving photoreceptors had shortened outer segments. The number of cones labeled by peanut agglutinin was decreased 50-60%. By 18 months, retinas from null mice were completely devoid of photoreceptors. There appeared to be few changes in the inner retina, although BETA2/NeuroD1 is expressed in this area. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining revealed a dramatic increase in cell death, peaking at approximately postnatal day 3 and continuing into adulthood. No defects in cell birth were detected using bromodeoxyuridine staining. Our results reveal that BETA2/NeuroD1 not only plays an important role in terminal differentiation of photoreceptors but also serves as a potential survival factor. Loss of BETA2/NeuroD1 results in an age-related degeneration of both rods and cones. |
