Phenotypes Associated with This Genotype

Genotype
MGI:5284889

• Allelic Composition: Sema5a^tm1.2Alk/Sema5a^tm1.2Alk; Sema5b^tm1.2Alk/Sema5b^tm1.2Alk
• Genetic Background: involves: 129 * BALB/cJ * C57BL/6

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

vision/eye

abnormal amacrine cell morphology ( J:174679 )

• dopaminergic amacrine cells exhibit dramatic mistargeting within both the inner nuclear layer and the outer plexiform layer

• Slc17a8-expressing amacrine cells show severe neurite mistargeting within both the inner plexiform layer and inner nuclear layer

• selective disruption of OFF but not ON arbors of amacrine cells in the retina

abnormal retina bipolar cell morphology ( J:174679 )

• ectopic band of bipolar cell axon terminals the colocalize with aberrantly projecting axon terminals of cone OFF bipolar cells within the inner nuclear layer

• cone OFF bipolar cells exhibit robust axon termination defects within the inner nuclear layer

• however, rod ON bipolar cells display mostly normal axonal terminations with only a very few mislocalized axon terminals within the inner nuclear layer

• type 3 OFF cone bipolar cell axonal terminations are more disorganized, exhibiting ectopic axonal terminations within the S1 sublamina or the inner nuclear layer

abnormal retina development ( J:174679 )

• at P3-P4 amacrine cells and calbindin positive retinal ganglion cell subtypes extend neurites toward the outer neuroblastic layer

• at P7 calbindin positive neurites extend within the inner nuclear layer forming an ectopic plexiform layer

• cholinergic amacrine cells and calretinin positive cells extend neurites within the inner nuclear layer at P3-P4 and P7

abnormal retina neuronal layer morphology ( J:174679 )

• at P7 calbindin positive neurites extend within the inner nuclear layer forming an ectopic plexiform layer

abnormal retina ganglion cell morphology ( J:174679 )

• M1-type intrinsically photosensitive RGC (ipRGC) dendrites fail to stratify in the S1 sublamina of the inner plexiform layer (IPL) and instead arborize in the inner nuclear layer and outer plexiform layer

• dendritic stratification of ipRGC subtypes in distinct IPL sublaminae at P14 is selectively disrupted

• selective disruption of OFF but not ON arbors of RGCs in the retina

• however, no defects in RGC axonal targeting are seen

abnormal retina inner nuclear layer morphology ( J:174679 )

• the ectopic plexiform layer creates a discontinuity among the Pax6 positive nuclei

abnormal retina inner plexiform layer morphology ( J:174679 )

• minor displacement of nuclei within the inner plexiform layer

abnormal eye physiology ( J:174679 )

• retinas show about a 5 fold increase in retinal ganglion cells that exhibit spontaneous neural activity but do not respond to whole field stimuli

• retinal ganglion cells display an ON-OFF index distribution that is heavily skewed toward ON responses

abnormal rod electrophysiology ( J:174679 )

• the amplitude of the b wave is significantly smaller

• however, the a wave is similar to double heterozygous controls

nervous system

abnormal neurite morphology ( J:174679 )

• severe defects in stereotypic neurite arborization of multiple amacrine cell types

• dopaminergic amacrine cells exhibit dramatic mistargeting within both the inner nuclear layer and the outer plexiform layer

• all amacrine cells, calretinin positive cells and calbindin positive cells exhibit pronounced ectopic neurite extension toward the outer retina

abnormal dendrite morphology ( J:174679 )

• M1-type intrinsically photosensitive retinal ganglion cell dendrites (ipRGC) fail to stratify in the S1 sublamina of the inner plexiform layer (IPL) and instead arborize in the inner nuclear layer and outer plexiform layer

• dendritic stratification of ipRGC subtypes in distinct IPL sublaminae at P14 is selectively disrupted

• selective disruption of OFF but not ON arbors of amacrine and retinal ganglion cells in the retina

abnormal amacrine cell morphology ( J:174679 )

• dopaminergic amacrine cells exhibit dramatic mistargeting within both the inner nuclear layer and the outer plexiform layer

• Slc17a8-expressing amacrine cells show severe neurite mistargeting within both the inner plexiform layer and inner nuclear layer

• selective disruption of OFF but not ON arbors of amacrine cells in the retina

abnormal retina bipolar cell morphology ( J:174679 )

• ectopic band of bipolar cell axon terminals the colocalize with aberrantly projecting axon terminals of cone OFF bipolar cells within the inner nuclear layer

• cone OFF bipolar cells exhibit robust axon termination defects within the inner nuclear layer

• however, rod ON bipolar cells display mostly normal axonal terminations with only a very few mislocalized axon terminals within the inner nuclear layer

• type 3 OFF cone bipolar cell axonal terminations are more disorganized, exhibiting ectopic axonal terminations within the S1 sublamina or the inner nuclear layer

abnormal retina ganglion cell morphology ( J:174679 )

• M1-type intrinsically photosensitive RGC (ipRGC) dendrites fail to stratify in the S1 sublamina of the inner plexiform layer (IPL) and instead arborize in the inner nuclear layer and outer plexiform layer

• dendritic stratification of ipRGC subtypes in distinct IPL sublaminae at P14 is selectively disrupted

• selective disruption of OFF but not ON arbors of RGCs in the retina

• however, no defects in RGC axonal targeting are seen