Phenotypes associated with this allele

• Allele Symbol: Brsk2^tm2.1Jrs
• Allele Name: targeted mutation 2.1, Joshua R Sanes
• Allele ID: MGI:5524054
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
cn1	Brsk2^tm2.1Jrs/Brsk2^tm2.1Jrs Chat^tm1(cre)Lowl/Chat^+	involves: 129S1/Sv * 129S6/SvEvTac * 129X1/SvJ	MGI:5524149
cn2	Brsk2^tm2.1Jrs/Brsk2^tm2.1Jrs Isl1^tm1(cre)Tmj/Isl1^+	involves: 129S1/Sv * 129X1/SvJ * C57BL/6 * SJL	MGI:5524148

Genotype
MGI:5524149

cn1

• Allelic Composition: Brsk2^tm2.1Jrs/Brsk2^tm2.1Jrs; Chat^tm1(cre)Lowl/Chat⁺
• Genetic Background: involves: 129S1/Sv * 129S6/SvEvTac * 129X1/SvJ

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

nervous system

nervous system phenotype ( J:201695 )

N • type Ia proprioceptive sensory neuron projections grow normally to the ventral horn

Genotype
MGI:5524148

cn2

• Allelic Composition: Brsk2^tm2.1Jrs/Brsk2^tm2.1Jrs; Isl1^tm1(cre)Tmj/Isl1⁺
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6 * SJL

mortality/aging

neonatal lethality, incomplete penetrance ( J:201695 )

• few mice survive beyond 24 hours after birth

nervous system

nervous system phenotype ( J:201695 )

N • interneurons exhibit normal migration to proper positions Golgi tendon organs are normally innervated

abnormal axon extension ( J:201695 )

• reduced outgrowths from type Ia proprioceptive sensory neuron in dorsal root ganglia explants in the presence of NT-3 or NGF

abnormal sensory neuron innervation pattern ( J:201695 )

• type Ia proprioceptive sensory neuron projections are disrupted and exhibit arrest at E15.5 as they reach the brainstem or ventral spinal cord in the medial spinal cord adjacent to the central canal and entire rostral-caudal extent of the spinal cord that persists through fetal development until P8 compared to in control mice

• type Ia proprioceptive sensory neuron projections fail to form terminal arbors

• mice exhibit defects in a second population of sensory neurons with few axons of the T12 dorsal root ganglion that cross the midline and only rare occurrences of axons that reach the proper contralateral target compared with control mice

• whisker axons have sparse arbors that fail to reach the correct target region in the bed nucleus of the stria terminalis (BSTC) without extensive branching

• however, mice exhibit normal growth of the sensory axons in the spinal cord and neuron targeting of nociceptive sensory axons in laminae I/IIi/IIo

• however, mice exhibit normal Pv+ proprioceptive axons growth into fore and hind limb muscles, trunk sensory axons form normal disc shaped endings on Merkel cells in the epidermis and axons in the deep vibrissal nerve that innervate whisker follicles

abnormal proprioceptive neuron morphology ( J:201695 )

• type Ia proprioceptive sensory neuron projections are disrupted and exhibit arrest at E15.5 as they reach the brainstem or ventral spinal cord in the medial spinal cord adjacent to the central canal and entire rostral-caudal extent of the spinal cord that persists through fetal development until P8 compared to in control mice

• type Ia proprioceptive sensory neuron projections fail to form terminal arbors

• fewer proprioceptor axons in the cuneate nucleus, but not the cuneate fascicle

• however, growth of the sensory axons in the spinal cord is normal

behavior/neurological

absent gastric milk in neonates ( J:201695 )

• little milk in stomachs

bradykinesia ( J:201695 )

• hypokinetic

cellular

abnormal axon extension ( J:201695 )

• reduced outgrowths from type Ia proprioceptive sensory neuron in dorsal root ganglia explants in the presence of NT-3 or NGF