All Phenotypes Slc24a1<tm1Xen> MGI Mouse

vision/eye

abnormal photoreceptor outer segment morphology ( J:226323 )

• slight thinning of the outer segment is seen at 6 months of age with progressive thinning of this layer to 1 year of age

• many outer segments are disrupted, with their discs occasionally arranged longitudinally rather than horizontally at 3 months

short retina cone cell outer segment ( J:226323 )

• cone outer segments become progressively shorter in older mice but cone numbers are maintained and degeneration is not seen

retina rod cell degeneration ( J:226323 )

thin retina outer nuclear layer ( J:226323 )

• slight thinning of the outer nuclear layer is seen at 6 months of age with progressive thinning of this layer to 1 year of age

increased susceptibility to age-related retinal degeneration ( J:226323 )

• mice exhibit slow progressive retinal degeneration

abnormal a-wave shape ( J:226323 )

• ERG recordings from dark-adapted mice show smaller scotopic a-waves

abnormal rod electrophysiology ( J:226323 )

• the rod flicker response is near saturation already at 3 Hz and is completely blocked at 6 Hz

• rod photoresponses are 100-fold smaller, the level of cGMP in the dark-adapted retinas is reduced, fractional sensitivity of rods is 2.5-fold higher, and the half-saturating flash energy of rods is over 2-fold lower

• dim flash responses of rods are smaller with 88% larger time-to-peak and 175% longer integration time indicating smaller and slower rod responses

nyctalopia ( J:226323 )

• stationary night blindness

• rod-mediated vision is desensitized and slow, with mice attaining the best contrast sensitivity at much brighter background light than wild-type mice and mice showing decreased sensitivity of rod-to-rod bipolar cell signaling

• however, Weber-like rod light adaptation is preserved and cone-mediated vision is not compromised

nervous system