Phenotypes Associated with This Genotype

Genotype
MGI:3621013

• Allelic Composition: Etv1^tm1Tmj/Etv1^tm1Tmj
• Genetic Background: involves: 129S1/Sv * C57BL/6J

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

mortality/aging

premature death ( J:78232 )

• die between 3 and 5 weeks of age

nervous system

abnormal muscle spindle morphology ( J:78232 )

• between E18 and P5 impaired muscle spindle differentiation is seen with loss of differentiated intrafusal fibers

• loss of differentiated intrafusal fibers varies between muscles with nearly complete loss in the gluteus, gracilis, biceps femoris, and semitendinosus muscles and partial loss in the pectoralis, adductor, and rectus femoris

• however, no defects in Golgi tendon organs are detected

abnormal sensory neuron innervation pattern ( J:78232 )

• fewer than 1% of the normal number of proprioceptive group 1a afferents are found in the ventral termination zone in the dorsal spinal cord; however densities in the dorsal and intermediate zones are normal

• a similar defect is seen at the forelimb and thoracic levels

• the number of PV+ axons within the muscle mass is reduced

impaired ability to fire action potentials ( J:78232 )

• after stimulation of the dorsal root ganglia monosynaptic responses are about 10 less than in wild-type and fail to evoke action potentials in motor neurons; however long-latency polysynaptic responses are similar to wild-type

• after cutaneous nerve stimulation the amplitude of monosynaptic responses is reduced between 4- and 40-fold

abnormal nerve conduction ( J:78232 )

• at P6 to P8, the latency of the fast component of compound sensory action potentials in the dorsal root ganglia is increased by 1 to 2 ms with a few axons showing even slower conduction velocities

behavior/neurological

ataxia ( J:78232 )

• limb ataxia

impaired limb coordination ( J:78232 )

• abnormal flexor-extensor posturing of the limbs

muscle

abnormal muscle spindle morphology ( J:78232 )

• between E18 and P5 impaired muscle spindle differentiation is seen with loss of differentiated intrafusal fibers

• loss of differentiated intrafusal fibers varies between muscles with nearly complete loss in the gluteus, gracilis, biceps femoris, and semitendinosus muscles and partial loss in the pectoralis, adductor, and rectus femoris

• however, no defects in Golgi tendon organs are detected