A mutation in the rod-specific enzyme cGMP phosphodiesterase causes photoreceptor degeneration in the rd/rd animal.
As a result, the rod outer segment membrane's cGMP-gated cation channels are permanently opened, allowing Na(+) and Ca(2+) ions to enter the cell and potentially lethal quantities of Ca(2+).
When being compared gene expression in the rd/rd and wild type (wt) mice retinas using U74A oligonucleotide arrays (Affymetrix)
During the recognized time period of photoreceptor degeneration in order to discover pathways implicated in cell death of the rd/rd rods.
By postnatal day 10, gene expression in rd/rd began to differ from wt.
The decrease in photoreceptor-specific genes coincided with the recognized progression of photoreceptor aging.
