Phenotypes associated with this allele

• Allele Symbol: Rorb^tm1Mba
• Allele Name: targeted mutation 1, Michael Becker-Andre
• Allele ID: MGI:2158692
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Rorb^tm1Mba/Rorb^tm1Mba	involves: 129P2/OlaHsd	MGI:5905354
hm2	Rorb^tm1Mba/Rorb^tm1Mba	involves: 129P2/OlaHsd * C57BL/6	MGI:3038368

Genotype
MGI:5905354

hm1

• Allelic Composition: Rorb^tm1Mba/Rorb^tm1Mba
• Genetic Background: involves: 129P2/OlaHsd

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

vision/eye

absent amacrine cells ( J:242481 )

absent retina rod cells ( J:242481 )

increased retina cone cell number ( J:242481 )

absent retina horizontal cells ( J:242481 )

absent photoreceptor inner segment ( J:242481 )

absent photoreceptor outer segment ( J:242481 )

abnormal retina inner plexiform layer morphology ( J:242481 )

• disorganized

disorganized retina outer plexiform layer ( J:242481 )

abnormal cone electrophysiology ( J:242481 )

• no scotopic or phototopic responses

abnormal rod electrophysiology ( J:242481 )

• no scotopic or phototopic responses

nervous system

absent amacrine cells ( J:242481 )

absent retina rod cells ( J:242481 )

increased retina cone cell number ( J:242481 )

absent retina horizontal cells ( J:242481 )

absent photoreceptor inner segment ( J:242481 )

absent photoreceptor outer segment ( J:242481 )

Genotype
MGI:3038368

hm2

• Allelic Composition: Rorb^tm1Mba/Rorb^tm1Mba
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

behavior/neurological

behavior/neurological phenotype ( J:48923 )

N • in spite of a grossly abnormal retina, homozygous mice remain entrained to the prevailing light/dark cycle

abnormal learning/memory/conditioning ( J:48923 )

decreased exploration in new environment ( J:48923 )

• reluctant to explore in a new environment

decreased aggression ( J:48923 )

• more docile than littermate controls

abnormal motor capabilities/coordination/movement ( J:48923 )

limb grasping ( J:48923 )

• hind paw grasping reflex when suspended by their tail

impaired coordination ( J:48923 )

• often fall over and roll when first beginning to walk

• gain muscular strength with age

abnormal gait ( J:48923 )

• develop a peculiar "duck-like" gait with age

abnormal social/conspecific interaction behavior ( J:48923 )

abnormal sexual interaction ( J:48923 )

♂ • although generally fertile, males do not breed successfully for the first six months

growth/size/body

decreased body size ( J:48923 )

• homozygotes are undersized

vision/eye

abnormal retina morphology ( J:48923 )

• severely malformed

disorganized retina layers ( J:48923 )

• disorganized and lacking the normal layer structure

• made up of significantly fewer cells

retina degeneration ( J:48923 )

• retinal degeneration apparently begins shortly after birth

abnormal eye physiology ( J:48923 )

• little visual activity in the retino-cortical pathway

nervous system

nervous system phenotype ( J:48923 )

N • no gross anatomical changes in brain