Phenotypes associated with this allele

• Allele Symbol: Cct2^em2Itwa
• Allele Name: endonuclease-mediated mutation 2, Takeshi Iwata
• Allele ID: MGI:7782499
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Cct2^em2Itwa/Cct2^em2Itwa	involves: C57BL/6J	MGI:7782502
ht2	Cct2^em1Itwa/Cct2^em2Itwa	involves: C57BL/6J	MGI:7782503

Genotype
MGI:7782502

hm1

• Allelic Composition: Cct2^em2Itwa/Cct2^em2Itwa
• Genetic Background: involves: C57BL/6J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

vision/eye

abnormal photoreceptor connecting cilium morphology ( J:358007 )

• a small number of photoreceptors exhibit spreading microtubles in the distal part of the connecting cilium

retina photoreceptor degeneration ( J:358007 )

• retinas at 43 weeks of age are depigmented and depleted of photoreceptors

• initiation of photoreceptor cell death appears at 4 weeks of age

• photoreceptor cell death occurs during outer nuclear layer (ONL) thinning at 7 weeks

• both rod and cone photoreceptors degenerate concurrently in the retina from week 4 to 10

• however, counts of retinal bipolar cells, amacrine cells, and retinal ganglion cells are not different and the outer segment and basal body appear normal

retina outer nuclear layer degeneration ( J:358007 )

• retinal pathology progresses from a blurred ellipsoid zone and reduced outer nuclear layer thickness at 4 weeks to more thinned ONL at 7 weeks and 10 weeks

• however, the inner nuclear layer is maintained

abnormal electroretinogram waveform feature ( J:358007 )

• ERG responses from rod and cone photoreceptors progressively decrease from week 4 to 10 and ERG responses are not recordable at 43 weeks

abnormal a-wave shape ( J:358007 )

• ERG indicates reduced scotopic a-wave and photopic a-wave

nervous system

abnormal photoreceptor connecting cilium morphology ( J:358007 )

• a small number of photoreceptors exhibit spreading microtubles in the distal part of the connecting cilium

retina photoreceptor degeneration ( J:358007 )

• retinas at 43 weeks of age are depigmented and depleted of photoreceptors

• initiation of photoreceptor cell death appears at 4 weeks of age

• photoreceptor cell death occurs during outer nuclear layer (ONL) thinning at 7 weeks

• both rod and cone photoreceptors degenerate concurrently in the retina from week 4 to 10

• however, counts of retinal bipolar cells, amacrine cells, and retinal ganglion cells are not different and the outer segment and basal body appear normal

cellular

abnormal photoreceptor connecting cilium morphology ( J:358007 )

• a small number of photoreceptors exhibit spreading microtubles in the distal part of the connecting cilium

Genotype
MGI:7782503

ht2

• Allelic Composition: Cct2^em1Itwa/Cct2^em2Itwa
• Genetic Background: involves: C57BL/6J

vision/eye

abnormal retina cone cell morphology ( J:358007 )

• aberrant cone cell localization in the retina indicating aberrant cone cell lamination

abnormal retina outer nuclear layer morphology ( J:358007 )

• some cone cell bodies are located in the middle of the outer nuclear layer (ONL) and the mean relative cone cell position is slightly, but significantly shorter, suggesting that cone cell migration is affected

• however, outer nuclear layer thickness is normal at P14, counts of cone photoreceptor cell bodies, bipolar cells, amacrine cells, and retinal ganglion cells are normal, and cone pedicle sizes are not different

nervous system

abnormal retina cone cell morphology ( J:358007 )

• aberrant cone cell localization in the retina indicating aberrant cone cell lamination

mortality/aging

postnatal lethality, complete penetrance ( J:358007 )

• mice do not survive longer than P14

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Leber congenital amaurosis		DOID:14791	OMIM:PS204000	J:358007