Phenotypes associated with this allele

• Allele Symbol: Robo3^tm1.1Ache
• Allele Name: targeted mutation 1.1, Alain Chedotal
• Allele ID: MGI:4441335
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
cn1	Dbx1^tm2(cre)Apie/Dbx1^+ Robo3^tm1.1Ache/Robo3^tm1.1Ache	involves: 129P2/OlaHsd * 129S2/SvPas * C57BL/6	MGI:4837353
cn2	Ptf1a^tm1.1(cre)Cvw/Ptf1a^+ Robo3^tm1.1Ache/Robo3^tm1.1Ache	involves: 129S1/Sv * 129S2/SvPas * 129X1/SvJ	MGI:4441338
cn3	Egr2^tm2(cre)Pch/Egr2^+ Robo3^tm1.1Ache/Robo3^tm1.1Ache	involves: 129S2/SvPas	MGI:4441336
cn4	Egr2^tm2(cre)Pch/Egr2^+ Robo3^tm1.1Ache/Robo3^tm1.1Ache Tg(Mnx1-EGFP)#Tmj/0	involves: 129S2/SvPas * C57BL/6 * DBA	MGI:4441376

Genotype
MGI:4837353

cn1

• Allelic Composition: Dbx1^tm2(cre)Apie/Dbx1⁺; Robo3^tm1.1Ache/Robo3^tm1.1Ache
• Genetic Background: involves: 129P2/OlaHsd * 129S2/SvPas * C57BL/6

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

mortality/aging

neonatal lethality, complete penetrance ( J:165285 )

• mice do not survive after birth

nervous system

abnormal medulla oblongata morphology ( J:165285 )

• mice exhibit reduced biocytin stained commissural interneurons in the pre-Botzinger complex compared with wild-type mice

abnormal pre-Botzinger complex morphology ( J:165285 )

• mice exhibit reduced biocytin stained commissural interneurons in the pre-Botzinger complex compared with wild-type mice

abnormal pre-Botzinger complex physiology ( J:165285 )

• mice exhibit de-synchronization of rhythmic activity in the left and right pre-Botzinger complex compared with wild-type mice

Genotype
MGI:4441338

cn2

• Allelic Composition: Ptf1a^{tm1.1(cre)Cvw}/Ptf1a⁺; Robo3^tm1.1Ache/Robo3^tm1.1Ache
• Genetic Background: involves: 129S1/Sv * 129S2/SvPas * 129X1/SvJ

Ataxic gait in Robo3^tm1.1Ache/Robo3^tm1.1Ache Ptf1a^{tm1.1(cre)Cvw}/Ptf1a⁺ mice

nervous system

abnormal brain commissure morphology ( J:158918 )

• severe impairment of the interolivary commissure

abnormal innervation ( J:158918 )

• only about 1/3 of inferior olivary neurons project contralaterally compared to wild-type controls where all neurons project contralaterally

behavior/neurological

abnormal motor coordination/balance ( J:158918 )

• in an Erasmus ladder test step time and overall walking pattern are severely abnormal

• impairment is more severe than that of Grid2^Lc mice

ataxia ( J:158918 )

• severe

impaired coordination ( J:158918 )

• decrease in latency to fall of a rotarod

• impairment is more severe than that of Grid2^Lc mice

Genotype
MGI:4441336

cn3

• Allelic Composition: Egr2^tm2(cre)Pch/Egr2⁺; Robo3^tm1.1Ache/Robo3^tm1.1Ache
• Genetic Background: involves: 129S2/SvPas

Reduced internuclear commissure in Robo3^tm1.1Ache/Robo3^tm1.1Ache Egr2^tm2(cre)Pch/Egr2⁺ mice

nervous system

abnormal brain commissure morphology ( J:158918 )

• at E11 - E12, a severe reduction of commissural projections in r3 and r5 is seen

• at E15 and in newborns, virtually no axons are found to cross the midline at the level of the abducens nuclei

abnormal innervation ( J:158918 )

• globular bushy cell projections from the anteroventral cochlear nucleus to the principal cells of the median nucleus of the trapezoid body are exclusively ipsilateral

behavior/neurological

abnormal reflex ( J:158918 )

• impairment in horizontal visual vestibuloocular reflex (VVOR) but not in vertical VVOR

abnormal optokinetic reflex ( J:158918 )

• impairment in horizontal OKR but not in vertical OKR

• defects occur predominantly in the low frequency range

abnormal horizontal vestibuloocular reflex ( J:158918 )

• impairment in horizontal VOR but not in vertical VOR

• defects in VOR are more predominant at high frequencies

hearing/vestibular/ear

abnormal horizontal vestibuloocular reflex ( J:158918 )

• impairment in horizontal VOR but not in vertical VOR

• defects in VOR are more predominant at high frequencies

abnormal auditory brainstem response ( J:158918 )

• 3 rather than 4 waves are present ipsilaterally and the third wave has a longer latency and is not followed by any identifiable wave

• the appearance of contralateral wave IVc is delayed compared to controls

Genotype
MGI:4441376

cn4

• Allelic Composition: Egr2^tm2(cre)Pch/Egr2⁺; Robo3^tm1.1Ache/Robo3^tm1.1Ache; Tg(Mnx1-EGFP)#Tmj/0
• Genetic Background: involves: 129S2/SvPas * C57BL/6 * DBA

nervous system

abnormal pons morphology ( J:158918 )

• at E14, the abducens motor nucleus is closer to the floor plate and abnormally shaped