Phenotypes associated with this allele
nervous system
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• YFP+ neurons exhibit one or more grossly enlarged, rounded mitochondria in the perinuclear region of the soma and in proximal segment of dendrites with some cells containing fragmented mitochondria and small, spherical mitochondrial clustered around the nucleus
• YFP+ neurons exhibit a progressive reduction in distal axonal mitochondrial numbers compared with control cells
• however, mitochondria in the distal dopamine axons are morphologically spared
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• neurons exhibit less intense staining with a retrograde tracer (fluorogold) suggesting impaired retrograde transport and/or uptake of the tracer compared with control cells
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nervous system
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• triple mutants show same phenotype as Tfamtm1Lrsn, Slc6a3tm1(cre)Lrsn mice; neuronal inclusions remain indicating that additional lack of Snca is not required for develoment of the Parkonsonian phenotype
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lmx1atm1Tpe mutation
(0 available);
any
Lmx1a mutation
(20 available)
Lmx1btm1Zfc mutation
(0 available);
any
Lmx1b mutation
(16 available)
Slc6a3tm1(cre)Lrsn mutation
(1 available);
any
Slc6a3 mutation
(66 available)
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behavior/neurological
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• novel object recognition test indicates impaired short-term memory formation in adult and aged mice
• however, no differences are seen in anxiety or depression-like tests
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• impaired motor coordination in the pole test at 6 months of age and in the beam traversal and pole test at 18 months of age
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• in the open field, mice show a modest increase in locomotor activity at 18, but not 6, months of age
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nervous system
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• midbrain dopamine neuron innervation is impaired
• treatment with rapamycin almost completely normalizes the reduced striatal TH innervation
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• 3 month old mice exhibit abnormal nerve terminals in the striatum, with a 50% reduction in the density of TH-positive nerve terminals and abnormally large nerve terminals that reach up to 22 um in diameter frequently throughout the dorsal and ventral striatum
• enlarged presynaptic boutons show fewer synaptic vesicles at active zones and are filled with vacuoles and multilamellar autophagic-lysosomal vesicles that sometimes contain mitochondria
• 23% lower occurrence of synaptic active zones
• treatment with rapamycin alleviates the occurrence of abnormally large TH+ boutons in the striatum
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• synaptic morphology is disrupted in presynaptic midbrain dopamine neuron terminals
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• enlarged presynaptic boutons show fewer synaptic vesicles at active zones
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• progressive loss of TH-positive neurons in the ventral midbrain, with degenerating TH+ neurons frequently seen in young mice; reduction is seen within both the dorsal and ventral striatum
• dopamine transporter (DAT) expression is reduced, showing a modest reduction in young mice but a significant reduction in aged mice, indicating dopaminergic neuron degeneration
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• mice exhibit enhanced induced LTP of Shaffer collateral-CA1 pyramidal cell synapses
• however, basal synaptic transmission is normal
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taste/olfaction
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• social olfaction is impaired in adult (6 months) and aged (18 months) mice
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cellular
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• accumulation of lysosomes in axonal terminals of midbrain dopamine neurons
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• accumulation of autophagosomes in axonal terminals of midbrain dopamine neurons
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• the number of lipofuscin granules are reduced in midbrain dopamine neurons
• accumulation of electron-dense protein aggregates in midbrain dopamine neuron cell bodies
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homeostasis/metabolism
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mfn1tm1.1Arte mutation
(0 available);
any
Mfn1 mutation
(44 available)
Slc6a3tm1(cre)Lrsn mutation
(1 available);
any
Slc6a3 mutation
(66 available)
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normal phenotype
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• viable with normal locomotor activity and body weight
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Nr4a2tm1.1Pcn mutation
(0 available);
any
Nr4a2 mutation
(40 available)
Slc6a3tm1(cre)Lrsn mutation
(1 available);
any
Slc6a3 mutation
(66 available)
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mortality/aging
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• mice do not survive beyond 3 weeks
• however, leaving pups with mothers improves perinatal survival beyond 3 weeks
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nervous system
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• expression of midbrain dopamine neuron markers is lost compared to in wild-type mice
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• mice exhibit a rapid loss of substantia nigra pars compacta cell bodies with only scattered ventral tegmental area neurons remaining compared with wild-type mice
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behavior/neurological
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• L-DOPA-treated mice exhibit hyperactivity unlike similarly treated wild-type mice
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• L-DOPA-treated mice exhibit repetitive behaviors (including repetitive gnawing, excessive grooming, and self-injury) unlike similarly treated wild-type mice
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homeostasis/metabolism
growth/size/body
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• at 2 months, mice left with their mothers after weaning are 40% smaller than wild-type mice
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mfn2tm1.1Arte mutation
(0 available);
any
Mfn2 mutation
(26 available)
Slc6a3tm1(cre)Lrsn mutation
(1 available);
any
Slc6a3 mutation
(66 available)
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mortality/aging
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• die before 7 weeks of age with a median survival of 5.8 weeks
• life span can be increased to 11-12 weeks of age when provided with moist food on the cage floor
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nervous system
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• pathological alterations (irregular margins and elongated nuclei) of the somata of the substantia nigra pars compacta are seen at 5 weeks of age
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• profound lack of dopaminergic neuron innervation in the striatum
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• severe respiratory chain deficiency in mitochondria in dopaminergic neurons
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growth/size/body
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• continue to lose weight even when provided with moist food on the cage floor
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behavior/neurological
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• total distance traveled is significantly increased in an open field test
• however, locomotion as assessed by horizontal beam breaks is similar to controls
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• decreased rearing activity in an open field test
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• become severely hypokinetic with age
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cellular
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• severe respiratory chain deficiency in mitochondria in dopaminergic neurons
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homeostasis/metabolism
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Gt(ROSA)26Sortm1Lrsn mutation
(1 available);
any
Gt(ROSA)26Sor mutation
(942 available)
Mfn2tm1.1Arte mutation
(0 available);
any
Mfn2 mutation
(26 available)
Slc6a3tm1(cre)Lrsn mutation
(1 available);
any
Slc6a3 mutation
(66 available)
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nervous system
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• profound reduction in the number of labeled mitochondria in the dorsal striatum
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• mitochondria are spherical and enlarged with disorganized cristae
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cellular
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• mitochondria in dopaminergic neurons are spherical and enlarged with disorganized cristae
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• profound reduction in the number of labeled mitochondria in the dorsal striatum
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• mitochondria in dopaminergic neurons are spherical and enlarged with disorganized cristae
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Mitochondria abnormalities in Tfamtm1Lrsn/Tfamtm1Lrsn Slc6a3tm1(cre)Lrsn/Slc6a3+ Gt(ROSA)26Sortm1Lrsn/Gt(ROSA)26Sor+ neurons
nervous system
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• YFP+ neurons exhibit one or more grossly enlarged, rounded mitochondria in the perinuclear region of the soma and in proximal segment of dendrites with some cells containing fragmented mitochondria and small, spherical mitochondrial clustered around the nucleus
• YFP+ neurons exhibit a progressive reduction in distal axonal mitochondrial numbers compared with control cells
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cellular
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• smaller mitochondrial and the largest aggregates in a rare number of neurons exhibit reduced import competence compared with mitochondria in control cells
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behavior/neurological
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• impaired from 20 weeks of age
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growth/size/body
muscle
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• rigidity from 20 weeks of age
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mortality/aging
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• mutants have to be terminated at ~45 weeks due to poor general condition
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behavior/neurological
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• mice aged 14-15 weeks display decreased exploratory activity
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• progressive Parkinsonian symptoms are observed, with tremor observed at 20 weeks of age
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• apparent limb rigidity is observed at 20 weeks of age
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nervous system
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• majority of neurons contain small cytoplasmic aggregates, detected at 6 weeks through 43 weeks
• inclusions are present in most dopaminergic midbrain neurons and the mean size increased as the neurodegeneration progressed
• large, partially electron-dense bodies located in dendritic structures close to neuronal somata are observed at 11 weeks; some of these bodies have an amorphous content with a diffuse lining, while others display tubular formations and have distinct double layer membranes which are ultrastructurally typical of mitochondrial membranes
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• dopaminergic (DA) neuron loss is observed in the dorsolateral striatum at 12 weeks of age, progressing to involve most of the dorsal and ventral striatum with age
• tyrosine hydroxylase-expressing midbrain neurons show a slow progressive cell loss, which is more marked and starts sooner in the substantia nigra compared to the ventral tegmental area
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muscle
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• twitching is observed at 20 weeks of age
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homeostasis/metabolism
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