Phenotypes Associated with This Genotype

Genotype
MGI:3817183

• Allelic Composition: Tg(MECP2)1Hzo/0
• Genetic Background: involves: FVB

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

mortality/aging

premature death ( J:94407 )

• 30% of mice die between 20 weeks and 1 year of age; mice surviving past 1 year of age have a normal lifespan

nervous system

nervous system phenotype ( J:126964 )

N • no alteration in synaptic release probability is detected in neurons

clonic seizures ( J:94407 )

• visually observed as early as 20 weeks of age, with increased frequency by 50 weeks

increased CNS synapse formation ( J:126964 )

• in vitro, density of synaptic markers is increased by 60%

• in vivo, at 2 weeks postnatal, number of glutamatergic synapses is increased by 80%; by 5 weeks, difference is much smaller but is still slightly significant

abnormal synaptic vesicle number ( J:126964 )

• neurons exhibit a 104% enhancement in RRP charge relative to wild-type

increased excitatory postsynaptic current amplitude ( J:126964 )

• evoked EPSC amplitudes show a 116% enhancement compared to wild-type

enhanced long-term potentiation ( J:94407 )

• robust enhancement is observed in mutants

abnormal miniature excitatory postsynaptic currents ( J:126964 )

• mEPSCs show a significant increase in frequency compared to wild-type

enhanced paired-pulse facilitation ( J:94407 )

• PPF is greatly enhanced in transgenic mice

behavior/neurological

abnormal contextual conditioning behavior ( J:94407 )

• in conditioned fear analysis, mutants and wild-type show similar results in cued fear conditioning, but in contextual conditioning, mutants show elevated freezing behavior indicating greater hippocampal learning

increased aggression ( J:94407 )

• increased propensity to bite

decreased anxiety-related response ( J:94407 )

• mice show lower anxiety evidenced by increased vertical activity in open field test

limb grasping ( J:94407 )

• forepaw clasping when lifted by tail

abnormal motor coordination/balance ( J:94407 )

• in dowel test, most animals remain inactive on wooden rod the entire trial period

enhanced coordination ( J:94407 )

• at 10 weeks of age, transgenics perform better on a rotating rod test on day 2 of training relative to wild-type; upon retesting at 20 weeks, mutants perform significantly better than wild-type

increased vertical activity ( J:94407 )

• mice show increased vertical activity compared to controls at 10 and 20 weeks

decreased locomotor activity ( J:94407 )

• in dowel test, transgenic animals display significantly reduced movement and walk off the length of an elevated dowel fewer times than wild-type

• characterized by freezing behavior

clonic seizures ( J:94407 )

• visually observed as early as 20 weeks of age, with increased frequency by 50 weeks

skeleton

kyphosis ( J:94407 )