Mouse Genome Informatics
hm
    Cngb1tm1.1Biel/Cngb1tm1.1Biel
involves: 129S1/Sv * 129X1/SvJ * C57BL/6N
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
mortality/aging

growth/size/body
• body weight at P30 is 10.4 g compared to 16.2 g for wild-type

vision/eye
• at 2 months of age the photoreceptor number is normal, at 4 months only 8-10 rows of photoreceptor nuclei are seen in the outer nuclear layer instead of the 10-12 rows normally present, and this decreases to 6 rows at 6 months and 1 discontinuous row at 10 months
• horizontal cell processes are retracted, only a single sprouting process is sent into the outer nuclear layer, and occasionally the cell bodies are misplaced into the outer plexiform layer
• rod bipolar cell processes are retracted, only a single sprouting process is sent into the outer nuclear layer, and occasionally the cell bodies are misplaced into the outer plexiform layer
• rod outer segments are shorter than normal starting at P15 before any degeneration is seen
• a slow progressing loss of photoreceptors that is slightly more sever in the periphery than in the central portion of the retina is seen beginning after 2 months of age
• cone morphology is normal however as the rod nuclei are lost the cone outer segments collapse so that by about 1 year essentially no rods or cones are present
• apoptosis of photoreceptors is seen after P15 and peaks between P21 and P28, during this time no apoptotic cells are seen in wild-type mice<
• single rod membrane currents indicate that only a few rods (3 out of 35) respond to light and the amplitude of these responses is only 10-15% of wild-type
• at 4 weeks and 6 months of age in dark-adapted conditions, electroretinographs from mutants show no response until the flash intensity reaches about 10-30 mcd/m2 compared to wild-type which respond to about 1 mcd/m2 suggesting that the rod system is not functional
• at 6 months of age, light-adapted responses are normal indicating that the cone system is functional; however, mid-wavelength- and short-wavelength-sensitive cones begin to degenerate after 6 months of age

nervous system
• at 2 months of age the photoreceptor number is normal, at 4 months only 8-10 rows of photoreceptor nuclei are seen in the outer nuclear layer instead of the 10-12 rows normally present, and this decreases to 6 rows at 6 months and 1 discontinuous row at 10 months
• horizontal cell processes are retracted, only a single sprouting process is sent into the outer nuclear layer, and occasionally the cell bodies are misplaced into the outer plexiform layer
• rod bipolar cell processes are retracted, only a single sprouting process is sent into the outer nuclear layer, and occasionally the cell bodies are misplaced into the outer plexiform layer
• rod outer segments are shorter than normal starting at P15 before any degeneration is seen
• a slow progressing loss of photoreceptors that is slightly more sever in the periphery than in the central portion of the retina is seen beginning after 2 months of age
• cone morphology is normal however as the rod nuclei are lost the cone outer segments collapse so that by about 1 year essentially no rods or cones are present
• apoptosis of photoreceptors is seen after P15 and peaks between P21 and P28, during this time no apoptotic cells are seen in wild-type mice<

Mouse Models of Human Disease
OMIM IDRef(s)
Retinitis Pigmentosa; RP 268000 J:95768