Phenotypes associated with this allele

• Allele Symbol: Dscam^del17
• Allele Name: deletion in exon 17
• Allele ID: MGI:3761008
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Dscam^del17/Dscam^del17	B6.CBy-Dscam^del17/RwbJ	MGI:4417836
hm2	Dscam^del17/Dscam^del17	either: (involves: BALB/cByJ * C57BL/6J) or (involves: 129S1/SvImJ * BALB/cByJ * C57BL/6J)	MGI:4834678
hm3	Dscam^del17/Dscam^del17	involves: BALB/cByJ * C57BL/6J	MGI:3769764
cx4	Dscam^del17/Dscam^del17 Dscaml1^Gt(CC0772)Wtsi/Dscaml1^Gt(CC0772)Wtsi	involves: 129P2/OlaHsd * BALB/cByJ * C57BL/6J	MGI:4417835

Genotype
MGI:4417836

hm1

• Allelic Composition: Dscam^del17/Dscam^del17
• Genetic Background: B6.CBy-Dscam^del17/RwbJ

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

mortality/aging

neonatal lethality, complete penetrance ( J:163979 )

• Background Sensitivity: homozygotes die shortly after birth but can survive when outcrossed to BALB or 129 strains

vision/eye

abnormal retina morphology ( J:155397 )

• dendrite fascicles are observed in the ON portion of the retina unlike in wild-type mice

• mosaic patterning of DA and intrinsically photoresponsive ganglion cells is disrupted

• however, gross synaptic lamination is intact

abnormal retina bipolar cell morphology ( J:155397 )

• retinal bipolar cell axons exhibit varicosities unlike in wild-type mice

abnormal retina ganglion layer morphology ( J:155397 )

• paired cholinergic and alpha retinal ganglion cell bands are not as compact as in wild-type mice

increased retina ganglion cell number ( J:155397 )

• in the peripheral retina

abnormal eye electrophysiology ( J:155397 )

• electroretinogram amplitude is decreased compared to in wild-type mice

nervous system

increased retina ganglion cell number ( J:155397 )

• in the peripheral retina

abnormal retina bipolar cell morphology ( J:155397 )

• retinal bipolar cell axons exhibit varicosities unlike in wild-type mice

Genotype
MGI:4834678

hm2

• Allelic Composition: Dscam^del17/Dscam^del17
• Genetic Background: either: (involves: BALB/cByJ * C57BL/6J) or (involves: 129S1/SvImJ * BALB/cByJ * C57BL/6J)

mortality/aging

postnatal lethality, incomplete penetrance ( J:163979 )

• Background Sensitivity: offspring from heterozygous intercrosses produce only 10.5% affected homozygotes, detected at 2 days of age from kyphosis and vestibular phenotype, and only 5.7% survive to wean age

prenatal lethality, incomplete penetrance ( J:163979 )

• less than the expected number of homozygotes are produced from heterozygous intercrosses

behavior/neurological

abnormal maternal behavior ( J:163979 )

♀ • while some homozygous females do reproduce and wean pups successfully, most fail to deliver and clean their pups and the pups are often found dead within an intact amniotic sac

Genotype
MGI:3769764

hm3

• Allelic Composition: Dscam^del17/Dscam^del17
• Genetic Background: involves: BALB/cByJ * C57BL/6J

craniofacial

abnormal cranial cavity morphology ( J:222353 )

• abnormal dome-shaped cranial cavities

domed cranium ( J:222353 )

• by 3 weeks of age, mice show dome-shaped heads

small ears ( J:222353 )

• tiny ears are seen by 3 weeks of age

mortality/aging

mortality/aging ( J:129238 )

N • lifespan of greater than 24 months is observed

growth/size/body

small ears ( J:222353 )

• tiny ears are seen by 3 weeks of age

postnatal growth retardation ( J:222353 )

• by 3 weeks of age, mice show reduced body size, however mice catch up in growth and body size is similar to wild-type mice by 2 months of age

vision/eye

abnormal amacrine cell morphology ( J:129238 )

• dopaminergic amacrine cells exhibit defects in arborization by postnatal day 6

• although process length and branch number are normal, there is an increase in the number of self-crossing processes that is evident by postnatal day 10

• processes from many cells form large fascicles in the retina

• dopaminergic amacrine cells associate with fascicles, exhibit abnormal positioning of cell bodies and clump

• Nos1-positive amacrine cells have short, bundled processes and randomly spaced cell bodies

delayed eyelid opening ( J:222353 )

• mice often show closed eyes at 3 weeks of age

disorganized retina ganglion layer ( J:129238 )

abnormal retina inner plexiform layer morphology ( J:129238 )

• mice exhibit disorganization of the IPL by postnatal day 4

hearing/vestibular/ear

small ears ( J:222353 )

• tiny ears are seen by 3 weeks of age

nervous system

seizures ( J:129238 )

abnormal brain morphology ( J:222353 )

• 2 of 5 mice at 2 months of age show obvious brain deformation

• some mice show severe deformation in the middle to caudal regions of the brain at 2 months of

abnormal cerebellar foliation ( J:129238 )

• disorganization of the caudal folium of the cerebellum

hydrocephaly ( J:222353 )

abnormal brain ventricle morphology ( J:222353 )

• the ratio of ventricular volume to brain volume is enlarged and absolute ventricular volume is larger

abnormal lateral ventricle morphology ( J:222353 )

• 3 of 5 mice exhibit lateral ventricles that are merged into one large ventricle and develop new ventricles located on the lateral of striatum on both sides

enlarged lateral ventricles ( J:222353 )

dilated brain ventricle ( J:222353 )

• all mice exhibit brain ventricular dilation, although severities and the affected regions vary among individual mice

dilated third ventricle ( J:222353 )

• dilation of the dorsal third ventricle and the third ventricle

enlarged cerebral aqueduct ( J:222353 )

• the aqueduct connecting the third and fourth ventricle is enlarged

abnormal brain commissure morphology ( J:222353 )

• the commissural fibers are thinner

abnormal corpus callosum morphology ( J:222353 )

• the corpus callosum fails to form properly with severe deformations especially in the caudal regions

• the dorso-ventral thickness of the corpus callosum is reduced in both the medial and cortical regions

• the corpus callosum forms thinner commissure in the medial region of the brain and appears disrupted or even disappears in caudal parts

abnormal brain internal capsule morphology ( J:222353 )

• internal capsule fibers are extended

decreased striatum size ( J:222353 )

• the striatum is constricted

abnormal hippocampus morphology ( J:222353 )

• the hippocampus shows malformations

abnormal cerebral cortex morphology ( J:222353 )

• 2 of 5 mice at 2 months of age show collapsed cortex in the lateral-caudal region

thin cerebral cortex ( J:222353 )

• different cortical regions such as motor and sensory cortices are displaced laterally and become much thinner

• the cortex fibers are thinner

small olfactory bulb ( J:222353 )

• 2 of 5 mice at 2 months of age show reduced olfactory bulb size

abnormal amacrine cell morphology ( J:129238 )

• dopaminergic amacrine cells exhibit defects in arborization by postnatal day 6

• although process length and branch number are normal, there is an increase in the number of self-crossing processes that is evident by postnatal day 10

• processes from many cells form large fascicles in the retina

• dopaminergic amacrine cells associate with fascicles, exhibit abnormal positioning of cell bodies and clump

• Nos1-positive amacrine cells have short, bundled processes and randomly spaced cell bodies

behavior/neurological

abnormal motor learning ( J:222353 )

• mice show impaired motor learning ability when trained on the rotarod for 8 trials in 2 days, with mice showing no change in average running time following the training sessions as seen in wild-type mice

impaired coordination ( J:129238 , J:222353 )

• mice exhibit severely impaired coordination by postnatal day 3 (J:129238)

• mice gradually become uncoordinated during the first 3 weeks after birth (J:222353)

• mice fall off the rotarod much sooner and at lower speeds than controls (J:222353)

• mice fail to stand steadily even on the resting rod and fall off within a short period of time (J:222353)

abnormal gait ( J:222353 )

• mice exhibit a walking posture that is different from wild-type mice, with mice standing on their toes and walking with tetanic hind limbs bent back, putting down their forelimbs and curving their tails downward to balance the body

seizures ( J:129238 )

skeleton

abnormal cranial cavity morphology ( J:222353 )

• abnormal dome-shaped cranial cavities

domed cranium ( J:222353 )

• by 3 weeks of age, mice show dome-shaped heads

kyphosis ( J:129238 )

Genotype
MGI:4417835

cx4

• Allelic Composition: Dscam^del17/Dscam^del17; Dscaml1^{Gt(CC0772)Wtsi}/Dscaml1^{Gt(CC0772)Wtsi}
• Genetic Background: involves: 129P2/OlaHsd * BALB/cByJ * C57BL/6J

vision/eye

abnormal retina morphology ( J:155397 )

• retinas are extremely disorganized compared to in wild-type mice

• the number of cells in the retina is increased compared to in wild-type mice

• however, some degree of costratification is maintained

• dendrite fascicles are observed in the outer nuclear portion of the retina unlike in wild-type mice

abnormal retina bipolar cell morphology ( J:155397 )

• retinal bipolar cell axons exhibit varicosities unlike in wild-type mice

abnormal retina ganglion layer morphology ( J:155397 )

• paired cholinergic and alpha retinal ganglion cell bands are not as compact as in wild-type mice

abnormal retina inner nuclear layer morphology ( J:155397 )

• a small number of cholinergic amacrine cell neuritis are laminated in an ectopic plexiform layer within the inner nuclear layer unlike in wild-type mice

• All amacrine cells stratify neuritis in an ectopic plexiform layer within the inner nuclear layer and project neurites past retinal bipolar cell terminals towards the retinal ganglion layer unlike in wild-type mice

nervous system

abnormal retina bipolar cell morphology ( J:155397 )

• retinal bipolar cell axons exhibit varicosities unlike in wild-type mice