Disruption of a retinal guanylyl cyclase gene leads to cone-specific dystrophy and paradoxical rod behavior
RB Yang, SW Robinson, WH Xiong… - Journal of …, 1999 - Soc Neuroscience
Journal of Neuroscience, 1999•Soc Neuroscience
One of two orphan photoreceptor guanylyl cyclases that are highly conserved from fish to
mammals, GC-E (or retGC1) was eliminated by gene disruption. Expression of the second
retinal cyclase (GC-F) as well as the numbers and morphology of rods remained unchanged
in GC-E null mice. However, rods isolated from such mice, despite having a normal dark
current, recovered from a light flash markedly faster. Unexpectedly, the a-and b-waves of
electroretinograms (ERG) from dark-adapted null mice were suppressed markedly. Cones …
mammals, GC-E (or retGC1) was eliminated by gene disruption. Expression of the second
retinal cyclase (GC-F) as well as the numbers and morphology of rods remained unchanged
in GC-E null mice. However, rods isolated from such mice, despite having a normal dark
current, recovered from a light flash markedly faster. Unexpectedly, the a-and b-waves of
electroretinograms (ERG) from dark-adapted null mice were suppressed markedly. Cones …
One of two orphan photoreceptor guanylyl cyclases that are highly conserved from fish to mammals, GC-E (or retGC1) was eliminated by gene disruption. Expression of the second retinal cyclase (GC-F) as well as the numbers and morphology of rods remained unchanged in GC-E null mice. However, rods isolated from such mice, despite having a normal dark current, recovered from a light flash markedly faster. Unexpectedly, the a- and b-waves of electroretinograms (ERG) from dark-adapted null mice were suppressed markedly. Cones, initially present in normal numbers in the retina, disappeared by 5 weeks, based on ERG and histology. Thus, the GC-E-deficient mouse defines a model for cone dystrophy, but it also demonstrates that morphologically normal rods display paradoxical behavior in their responses to light.
Soc Neuroscience