Phenotypes associated with this allele

• Allele Symbol: L1cam^tm1Mtei
• Allele Name: targeted mutation 1, Ned Mantei
• Allele ID: MGI:2181735
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
ot1	L1cam^tm1Mtei/Y	either: (involves: 129/Sv * C57BL/6J) or (involves: 129/Sv * 129S/SvEv)	MGI:3624801
ot2	L1cam^tm1Mtei/Y	involves: 129	MGI:3805890
ot3	L1cam^tm1Mtei/Y	involves: 129 * C57BL/6J	MGI:3624746

Genotype
MGI:3624801

ot1

• Allelic Composition: L1cam^tm1Mtei/Y
• Genetic Background: either: (involves: 129/Sv * C57BL/6J) or (involves: 129/Sv * 129S/SvEv)

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

growth/size/body

decreased body size ( J:43838 )

♂ • mutant mice are smaller than wild-type

behavior/neurological

abnormal motor capabilities/coordination/movement ( J:43838 )

♂ • mutants have trouble using their hindlimbs and often stumble (ie. when walking over a metal grid)

abnormal response to tactile stimuli ( J:43838 )

♂ • mutants show no reaction to being touched lightly on the flank or to a needle poke

impaired limb coordination ( J:43838 )

♂ • hind legs of mutants appear weak and uncoordinated

decreased grip strength ( J:43838 )

♂ • when placed on a metal grid which is then inverted, mutants often lose their grip (11/17) and fall with a average time to falling 17.7 seconds compared to wild-type (1 animal fell after 56 seconds)

abnormal thermal nociception ( J:43838 )

♂ • mutants placed on a warm plate display a delay in jumping off the plate compared to wild-type

nervous system

enlarged brain ventricles ( J:43838 )

♂ • Background Sensitivity: a high percentage of male mutants on the C57BL/6J background displayed enlarged brain ventricles; on a 129/SvEv background, no animals had enlarged ventricles

abnormal Schwann cell morphology ( J:43838 )

♂ • in mutants, many non-myelinating Schwann cells (87%) form additional processes, protruding in the endoneurial space not associated with axons and covered by a basal lamina; no wild-type non-myelinating Schwann cells have such processes

decreased corticospinal tract size ( J:43838 )

♂ • size is reduced in mutants

abnormal neuron morphology ( J:43838 )

♂ • when cultured on poly-L-lysine + L1 substrate, mutant cerebellar neurons show no outgrowth whereas wild-type neurons grow vigorously

♂ • cerebellar explants from mutant mice show reduced fasciculation compared to wild-type

vision/eye

enophthalmos ( J:43838 )

♂ • eyes of mutants are set further back in their sockets

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
MASA syndrome		DOID:0060246	OMIM:303350	J:43838

Genotype
MGI:3805890

ot2

• Allelic Composition: L1cam^tm1Mtei/Y
• Genetic Background: involves: 129

nervous system

nervous system phenotype ( J:136656 )

♂N • Purkinje dendrites appear normal

Genotype
MGI:3624746

ot3

• Allelic Composition: L1cam^tm1Mtei/Y
• Genetic Background: involves: 129 * C57BL/6J

craniofacial

enlarged cranium ( J:107878 )

♂ • mutants displaying severe hydrocephaly have significant enlargement of the skull

nervous system

hydrocephaly ( J:107878 )

♂ • severe hydrocephaly is seen in 4/70 mutants

enlarged brain ventricles ( J:107878 )

♂ • Background Sensitivity: when backcrossed onto a C57BL/6J background, mutants eventually develop enlarged ventricles

♂ • four mutants with severe hydrocephaly have massively enlarged ventricles

abnormal cerebral aqueduct morphology ( J:107878 )

♂ • all mutant mice with enlarged ventricles examined have patent cerebral aqueducts: in severely hydrocephalic mutants the cerebral aqueduct is closed and elongated in a dorso-ventral direction

abnormal hippocampus morphology ( J:107878 )

♂ • in mutants with severely enlarged ventricles, the hippocampus is displaced from a medio-lateral to a ventro-dorsal orientation

thin cerebral cortex ( J:107878 )

♂ • the mutant with severe hydrocephaly has a significantly thinned cerebral cortex

cerebellum atrophy ( J:107878 )

♂ • severely hydrocephalic mutants display cerebellar atrophy

skeleton

enlarged cranium ( J:107878 )

♂ • mutants displaying severe hydrocephaly have significant enlargement of the skull

growth/size/body

decreased body size ( J:107878 )

♂ • L1cam-deficient mice are smaller than wild-type littermates