MOUSE MODELS OF RETINAL DEGENERATION

RD10 MICE

These mice harbor a point mutation in the PDE6b gene which is required for the phototransduction cascade. As such, these mice develop a severe and progressive retinal degeneration that begins with photoreceptor cell death. As opposed to other retinal degeneration models in which the retina has degenerated completely by P21, these mice do not lose their complement of photoreceptors until ~P35. Moreover, this loss can be delayed until ~P50 by rearing newborn pubs in the dark until they are of adult age (P21), which provides a larger window for therapeutic intervention. The severity of retinal degeneration can be monitored by histological cell counts, biochemical analyses of photoreceptor gene and protein expression, and visual function by electroretinography. This is an excellent animal model for screening neuroprotective compounds that could delay or prevent photoreceptor cell death that occurs in retinitis pigmentosa, macular degeneration, and diabetic retinopathy.

RDS MICE

This mice are genetic knockouts for the Rds gene, which produces a structural protein required for the formation of photoreceptor outer segments. In the absence of outer segments, the retina of these mice degenerate, but at a much slower rate (several months). If addition, Rds+/- mice can also be used wherein some misformed outer segments are present, and the rate of retinal degeneration is delayed even further. The Rds mouse presents a unique model to test neuroprotective compounds, especially since several human mutations in Rds have been associated with various forms of macular degeneration.