Phenotypes Associated with This Genotype

Genotype
MGI:6302764

• Allelic Composition: Borcs7^Q87X/Borcs7^Q87X
• Genetic Background: involves: 129S6/SvEvTac * C57BL/6 * DBA/2

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

behavior/neurological

abnormal spatial learning ( J:271219 )

• mice show only mild changes in the Morris water maze, with longer latencies to the escape platform on the 3rd day of testing

decreased startle reflex ( J:271219 )

• mice show a small, but significant, reduction in the startle amplitudes at 6 weeks of age, but the difference is no longer seen in subsequent tests

limb grasping ( J:271219 )

• hind limb clasping

ataxia ( J:271219 )

• hind limb ataxia emerges during the adolescent period

impaired coordination ( J:271219 )

• in the accelerating roatarod, mice show reduced latency to fall at 5 and 8 weeks of age

decreased grip strength ( J:271219 )

• in the wire-hang task, mice show reduced latency to fall and decreased overall coordination score at 4 and 8 weeks of age

abnormal gait ( J:271219 )

• altered gait, with progressive severity as mice age

decreased vertical activity ( J:271219 )

• mice show a reduction in rearing at 8 weeks, but not 5 weeks, of age, consistent with loss of hind limb strength

hyperactivity ( J:271219 )

• mice are hyperactive in a novel environment at 5 weeks of age, showing increased general activity in the beginning intervals of test

• however, by the second test at 8 weeks of age, no differences are seen

cellular

abnormal lysosome morphology ( J:271219 )

• modest, but significant, decrease in the number of lysosomes in axons of cortical neurons

nervous system

axonal dystrophy ( J:271219 )

• motor neurons within the ventral horn and sciatic nerve show Luxol Fast Blue stained spherical bodies indicating dystrophic axons

• spheroids show dense accumulations of organelles in various stages of degeneration

• swollen axons are pronounced and numerous in the spinal cord, affecting both myelinated and unmyelinated fibers

• swollen axons have tubulovesicular elements forming an anastomosing, curvilinear network of delicate membrane structures with lumens indicative of dystrophic axons

abnormal axonal transport ( J:271219 )

• neurons show decreased anterograde velocity of LAMP1-GFP-labeled lysosomes compared to controls

• neurons show reduction in both anterograde and retrograde lysosomal run length

reproductive system

reduced male fertility ( J:271219 )

♂ • males exhibit decreased fertility by 15 weeks of age due to progressive loss of motor coordination

♂ • however, sperm are able to fertilize oocytes

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
hereditary spastic paraplegia		DOID:2476	OMIM:PS303350	J:271219
neuroaxonal dystrophy		DOID:2367		J:271219