mortality/aging
• some mice exhibit difficulty in delivering full-term offspring resulting in the death of the mother
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reproductive system
N |
• despite pregnancy-associated lethality, uterine structure and position are normal
• despite male infertility, spermatogenesis and morphology of male reproductive organs are normal
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• male mice are infertile likely due to hindlimb defects
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behavior/neurological
• 70% of mice are unable to bring their hindlimbs together to grasp a midline object unlike wild-type mice
• 30% of mice exhibit difficulties in adduction motion needed to grasp a midline object unlike wild-type mice
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• mice exhibit abnormal gait, adduction, mobility, and weight-bearing ability
• mice walk with their feet positioned outward, generating a large angle between their feet position and their direction of motion unlike wild-type mice
• mice distribute their weight more uniformly over the entire lower surface of their feet compared with wild-type mice
• mice drag their feet during locomotion unlike wild-type mice
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abnormal gait
(
J:59070
)
• 65% of mice exhibit mild gait abnormalities including increased hindlimb stiffness, jerky gait, and abnormal outward positioning of the hind feet
• 12% of mice exhibit severe gait abnormalities including pronounced hindlimb stiffness, abnormal posterior hindlimb extension, and improper weight distribution
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• during an open field test, mice stand upright less frequent than wild-type mice
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• mice enter fewer quadrants in an open field-test compared to wild-type mice
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nervous system
• at E13.5, fibers in the tibial nerve arbor lack identifiable fascicles unlike in wild-type mice
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• L3 projection is greatly reduced compared to in wild-type mice
• in 36% of mice the tibial nerve is truncated and the distal arbor is missing unlike in wild-type mice
• some mice exhibit disorganized tibial nerve arbors with fewer nerve fibers and well-defined nerve branches compared to in wild-type mice
• at E13.5, fibers in the tibial nerve arbor lack identifiable fascicles unlike in wild-type mice
• the deep branch of the peroneal nerve exhibits a 40% reduction in nerve diameter compared to in wild-type mice
• peripheral nerve projections are abnormal with 1 hindlimb lacking the common peroneal nerve, 10 hindlimbs exhibiting reduced common peroneal nerve, and 2 hindlimbs exhibiting reduced tibial nerve
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• in one hindlimb the sciatic nerve branches into 3 nerves instead of 2 as in wild-type mice
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limbs/digits/tail
• 17% of mice exhibit an ectopic sesamoid bone on the dorsal aspect of the forelimb curved around the base of the humerus opposite the position of the orthotopic sesamoid bone present on the ventral side of the forelimb
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• 11% of mice exhibit a flattened humeral head compared to in wild-type mice
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• 13% of mice exhibit alterations in the deltoid crest such that the slope of the crest begins more distally than normal and the size of the crest is reduced compared to in wild-type mice
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• mice occasionally lack a single muscle in the medial and lateral regions of the distal hindlimb while forelimb muscles are minimally affected
• most muscles, with the exception of the peroneus brevis, appear to be deleted in at least one mouse, with the flexor hallucis longus, peroneus tertius, fourth digit dorsolateral, and fifth digit lateral most often affected
• hindlimb tendons are reduced in size and misrouted compared to in wild-type mice
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• the patella is smooth and oval to highly irregular in shape or even composed of several parts unlike in wild-type mice
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• 32% of mice exhibit small ectopic anterior sesamoid bones proximal to the patella
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skeleton
• 11% of mice exhibit a flattened humeral head compared to in wild-type mice
|
• 13% of mice exhibit alterations in the deltoid crest such that the slope of the crest begins more distally than normal and the size of the crest is reduced compared to in wild-type mice
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• the patella is smooth and oval to highly irregular in shape or even composed of several parts unlike in wild-type mice
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• 32% of mice exhibit small ectopic anterior sesamoid bones proximal to the patella
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• hindlimb tendons are reduced in size and misrouted compared to in wild-type mice
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• 18 mice exhibit alterations in the shape and position of spinous processes on lumbar vertebrae
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• sacral vertebrae posterior to S1 exhibit shape changes in the transverse processes producing additional vertebra with wing-shaped transverse processes
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• 31 of 41 mice exhibit anterior transformation of S1
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• 27% of hind limbs exhibit a shift in the articulation point between the femur and tibia producing outward rotation o the lower part of the limb
• spacing between the femur and tibia is expanded compared to in wild-type mice
• 74% of mice exhibit a shift in the patella proximal to the lateral epicondyle
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• 25 of 41 mice exhibit four fused sacral vertebrae
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muscle
• mice occasionally lack a single muscle in the medial and lateral regions of the distal hindlimb while forelimb muscles are minimally affected
• most muscles, with the exception of the peroneus brevis, appear to be deleted in at least one mouse, with the flexor hallucis longus, peroneus tertius, fourth digit dorsolateral, and fifth digit lateral most often affected
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• hindlimb tendons are reduced in size and misrouted compared to in wild-type mice
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renal/urinary system
small kidney
(
J:59070
)
• at E15.5 and in newborn mice kidney size is 70% of normal
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cellular
• at E13.5, fibers in the tibial nerve arbor lack identifiable fascicles unlike in wild-type mice
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