Phenotypes associated with this allele

• Allele Symbol: Unc5c^rcm
• Allele Name: rostral cerebellar malformation
• Allele ID: MGI:1857013
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Unc5c^rcm/Unc5c^rcm	B6C3Fe a/a-Unc5c^rcm/J	MGI:2446448
hm2	Unc5c^rcm/Unc5c^rcm	C57BL/6J-Unc5c^rcm	MGI:3665578

Genotype
MGI:2446448

hm1

• Allelic Composition: Unc5c^rcm/Unc5c^rcm
• Genetic Background: B6C3Fe a/a-Unc5c^rcm/J

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

reproductive system

reproductive system phenotype ( J:1827 )

N • Background Sensitivity: males on this hybrid background can sire litters unlike males on an inbred C57BL/6J background

nervous system

abnormal neuronal migration ( J:45577 )

• abnormal rostral migration of Purkinje and granule cells into the inferior colliculus

abnormal cerebellum development ( J:40243 , J:45577 )

• an abnormal band of granule cells extends from the cerebellum into the inferior colliculus (J:40243)

• partial fusion of the inferior colliculus to the rostral cerebellum (J:40243)

• expression analysis identifies neuroprogenitors ectopically located beneath the pia mater and at E17.5 these cells extend more rostrally than the Purkinje cell progenitors (J:45577)

• ectopic cerebellar cells are seen in the inferior colliculus and pontine area at P7 (J:45577)

abnormal cerebellar lobule formation ( J:40243 )

• only 6 lobes are formed

• vermal fissure formation is also abnormal in the lateral cerebral hemisphere

reduced cerebellar foliation ( J:40243 )

• a reduction in size and number of folia is seen in midline sagital sections

abnormal cerebellum external granule cell layer morphology ( J:40243 )

• abnormal external granule cell migration with cells migrating in cohorts rather than as single cells

• these abnormal groups of cells are often associated with gaps in the Purkinje cell layer

abnormal inferior colliculus morphology ( J:40243 )

• an abnormal band of granule cells extends from the cerebellum into the inferior colliculus

• partial fusion of the inferior colliculus to the rostral cerebellum with ectopic granule and Purkinje cells in the inferior colliculuc and tegmentum of the midbrain

abnormal cerebellar Purkinje cell layer ( J:40243 )

• abnormal groups of migrating granule cells are associated with gaps in the Purkinje cell layer

abnormal Purkinje cell morphology ( J:45577 )

• at E13.5 Purkinje cell progenitors extend slightly more rostrally towards the pontine area

ectopic Purkinje cell ( J:1827 , J:40243 , J:45577 )

• scattered randomly through the granule cell layer and cells are also seen in some areas of the molecular layer, all in the parafloccular lobe lateral to the midbrain (J:1827)

• in the inferior colliculus and tegmentum of the midbrain (J:40243)

• ectopic cells are detected at P3 but not at P0 (J:40243)

• at E17.5 Purkinje cells invade the lateral regions of the pontine area (J:45577)

• in the inferior colliculus and pontine area at P7 (J:45577)

abnormal cerebellar granule layer morphology ( J:1827 )

• variable thickness and cell density in the parafloccular lobe lateral to the midbrain

• throughout the cerebellum small tongue-like extensions of the molecular layer into the granule cell layer are seen

ectopic cerebellar granule cells ( J:1827 , J:40243 , J:45577 )

• in some areas of the molecular layer in the parafloccular lobe lateral to the midbrain (J:1827)

• an abnormal band of granule cells extends from the cerebellum into the inferior colliculus (J:40243)

• ectopic cells are first detected at P3 and increase in number by P7 (J:40243)

• in the inferior colliculus and pontine area at P7 (J:45577)

abnormal cerebellar molecular layer ( J:1827 )

• throughout the cerebellum small tongue-like extensions of the molecular layer into the granule cell layer are seen

small cerebellum ( J:40243 , J:45577 )

• less pronounced than in Unc5c^{rcmTg(Ucp)1.23Kz} homozygotes (J:40243)

• seen at E17.5 (J:45577)

behavior/neurological

ataxia ( J:1827 )

abnormal gait ( J:1827 )

• swaying gait seen at 12 days of age

growth/size/body

postnatal growth retardation ( J:1827 )

• smaller than littermates at 12 days of age but catch up in size by 5 - 6 weeks of age

cellular

abnormal neuronal migration ( J:45577 )

• abnormal rostral migration of Purkinje and granule cells into the inferior colliculus

Genotype
MGI:3665578

hm2

• Allelic Composition: Unc5c^rcm/Unc5c^rcm
• Genetic Background: C57BL/6J-Unc5c^rcm

mortality/aging

preweaning lethality, incomplete penetrance ( J:1827 )

• fewer than expected homozygotes are found at weaning; however, those that survive to weaning have a normal life span

reproductive system

male infertility ( J:1827 , J:14268 )

♂ • Background Sensitivity: males on an inbred C57BL/6J background fail to sire litters however, males on a hybrid B6C3Fe a/a background may sire litters (J:1827)

♂ (J:14268)

nervous system

increased inferior colliculus size ( J:46670 )

• appears to extend further posteriorly

abnormal cerebellum morphology ( J:46670 )

• in lateral sections the cerebellum extends further anteriorly especially in the lateral vermal and paravermal regions

• ectopic cerebellar tissue adheres to the posterior and lateral aspects of the inferior colliculus and along the lateral aspect of the brainstem

• ectopic tissue is present paramedially but not at the midline and does not contain cerebellar nuclear cells

• increased dispersal of cerebellar mossy fiber terminals and additional spinocerebellar mossy fiber terminal bands lateral to the usual 5 bands are seen in the anterior and ectopic cerebellar tissue; however mossy fibers in the posterior region appear similar to wild-type

abnormal cerebellar layer morphology ( J:46670 )

• abnormalities of the layers are more severe in the ectopic tissue

abnormal cerebellar Purkinje cell layer ( J:46670 )

• increasing degree of multilamination as the normal anterior boundary of the cerebellum is approached

ectopic Purkinje cell ( J:14268 , J:46670 )

• Purkinje and granule cells are scrambled (J:14268)

• within the granule cell layer in the ectopic cerebellar tissue (J:46670)

abnormal cerebellar granule layer morphology ( J:46670 )

• acellular areas interrupt this layer

ectopic cerebellar granule cells ( J:14268 , J:46670 )

• Purkinje and granule cells are scrambled (J:14268)

• in the medullary regions especially in the medial area of lobule VI (J:46670)

• clusters of ectopic granule cells in the molecular layer in the ectopic cerebellar tissue (J:46670)

abnormal cerebellum anterior lobe morphology ( J:14268 )

• irregular thickness of the anterior lobe

abnormal cerebellum vermis lobule morphology ( J:46670 )

• smaller lobule V and less pronounced hemispheric part of lobule VI

• lobule VI does not appear to extend to the lateral aspect of the hemisphere

• lobule IX is reduced and appears to be joined to lobule VIII in the midline region

• the medial cerebellum usually has only 2 lobules rather than 3 as in wild-type mice

small cerebellum ( J:46670 )

behavior/neurological

tremors ( J:46670 )

• slight

ataxia ( J:14268 , J:46670 )

• tend to fall to the side (J:14268)

• tend to fall to one side, lean to one side when walking, and only rear when support is available (J:46670)

abnormal posture ( J:46670 )

• broad stance of the hind limbs

• when walking hind limbs and toes are splayed

head bobbing ( J:46670 )

• tend to bob up and down or side to side

abnormal gait ( J:1827 )

• swaying gait seen at 12 days of age

growth/size/body

postnatal growth retardation ( J:1827 )

• smaller than littermates at 12 days of age but catch up in size by 5 - 6 weeks of age