Phenotypes associated with this allele
mortality/aging
 |
• 50% mortality by 29-35 weeks of age
|
behavior/neurological
|
|
• mice exhibit repetitive nose-poking behavior in the hole board test
• however, mice do not exhibit motor deficits or alternations in acoustic startle response, partition, or cued memory tests, or differences in anxiety, pre-pulse inhibition, locomotor activity or long-term potentiation
|
|
|
• 50% of mice develop spontaneous epileptic seizures starting at 12 weeks
|
|
|
• mice show generalized tonic clonic seizures during routine handling
|
nervous system
|
|
• 50% of mice develop spontaneous epileptic seizures starting at 12 weeks
|
|
|
• mice show generalized tonic clonic seizures during routine handling
|
Allelic
Composition |
Mecp2tm1Bird/Y
Pvalbtm1.1(cre)Aibs/Pvalb+
|
|
Genetic
Background |
involves: 129P2/OlaHsd * 129S4/SvJaeSor * 129S6/SvEvTac * C57BL/6J * C57BL/6NCrl |
|
|
|
mortality/aging
|
|
• 50% mortality by 29-35 weeks of age
|
behavior/neurological
|
|
• mice develop progressive cued memory deficits, with the difference in freezing response to a conditioned tone becoming significantly different at 15 weeks of age
|
|
|
• mice show a diminished acoustic startle response
|
|
|
• mice develop progressive ataxia that is apparent at 6 weeks and worsens by 20 weeks
• however, mice do not exhibit seizures or stereotypical behaviors
|
|
|
• mice exhibit reduced latency to fall in both the rotarod and dowel walk assays
• mice exhibit impaired performance of the marble-burying test, suggesting forelimb incoordination
|
|
|
• mice develop widely splayed hind limbs after 10 weeks and hind limb retraction after 15 weeks of age
|
|
|
• mice spend more time interacting with novel partner mice in a social behavior assay
|
|
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
Tg(dlx5a-cre)1Mekk mutation
(2 available)
|
|
|
mortality/aging
|
N |
• mice survive to at least 80 weeks of age
|
behavior/neurological
|
N |
• mice show similar grooming times to controls
• mice have a nonsignificant trend to reduced total distance traveled
• time exhibiting aggressive behavior such as wrestling, tail-rattling, boxing, and mounting is similar to controls
• mice exhibit intact olfactory recognition and habituation in response to a novel odorant at 11 weeks of age
• at 12 weeks, mice have intact nociception demonstrated by a hot-plate or tail-flick assay
|
|
|
• mice show impaired maximum acoustic startle response to 120dB
|
|
|
• mice display more footslips, shorter latency to fall on wire, reduced number of side touches on dowel and shorter latency to fall from rotarod compared to controls
|
|
|
• mice show a 200% increase relative to control in number of holes explored with 2 or more sequential nose pokes in a holeboard assay
|
|
|
• nest building is impaired
|
|
|
• mice show increased social interaction with novel and familiar partners; time spent with novel partners is 60% higher than in controls in a 3-chamber assay
|
nervous system
|
|
• 24 week-old mice show increased prepulse inhibition at 74 dB
|
respiratory system
|
N |
• mice show no alterations in tidal volume or minute volume, and display no apneas
|
|
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
Tg(Slc32a1-cre)2.1Hzo mutation
(1 available)
|
|
|
mortality/aging
|
|
• around 50% of mutant mice die by 26 weeks
|
growth/size/body
|
|
• mice exhibit a period of rapid weight loss preceding death; initial weight gain is normal
|
behavior/neurological
|
N |
• at 12 weeks of age, mice show similar responses to controls in thermal nociception assays, indicating that the self-injury observed is not due to impaired nociception
• mice display no anxiety-like phenotypes, indicating that hypoactivity or altered social behavior does not result from increased anxiety
• animals show no increased interest in a novel object than controls at 11-12 weeks
• mice recognize and habituate to a novel vanilla odorant; mutants did spend more time sniffing the novel scent than controls (possible manifestation of repetitive behavior) on the first day, but show no differences on the second day
|
|
|
• in a Morris water maze paradigm, animals show a similar rate of learning to control during the 4 training days, but have difficulty locating the platform during the probe trial
|
|
|
• time spent grooming is 300% greater than in control mice; excessive grooming leads to fur loss and epidermal lesions in group- and single-housed mice
|
|
|
• mice have impaired maximum acoustic startle response than controls to 120 dB at 8 weeks
|
|
|
• after 5 weeks of age, mice show repetitive behavior such as hindlimb clasping
|
|
|
• at 5 weeks, mice show increased numbers of footslips on a wire grid and impaired dowel walk at 9 weeks
• mice have a shorter latency to fall on an accelerating rotarod at 19 weeks
|
|
|
• at 9 weeks, mice show decreased time wire hang time prior to falling and reduce forelimb grip strength compared to controls
|
|
|
• there is a trend to reduced activity observed at 12 weeks, while 19-week old mice are hypoactive
|
|
|
• male mice begin to show repetitive behaviors after 5 weeks of age such as forelimb stereotypies similar to the mid-line hand-wringing that characterizes Rett syndrome in humans
• animals display a greater tendency to place their nose in the same hole 2 or more sequential times in a holeboard assay for head-dipping stereotypy
|
|
|
• mice are poor nest builders, possibly due to social behavior alterations or to forelimb apraxia at 13 weeks
|
|
|
• mice spend more time showing directed interest (sniffing, pawing, rearing) near the novel partner mouse than displayed by controls in a 3-chamber assay of social interaction at 12-13 weeks
|
nervous system
|
N |
• miniature excitatory postsynaptic current quantal size and frequency are similar to controls
• paired pulse ratio is not significantly altered in neurons
|
|
|
• non-seizure hyperexcitability discharges are frequently observed in cultured neurons, but no electrographic seizures are seen
|
|
|
• impaired LTP induced by theta-burst stimulation of Schaffer collaterals is detected
|
|
|
• amplitude and charge of mIPSCs from layer 2/3 pyramidal neurons of the somatosensory cortex are reduced; no change in frequency is observed
• similar results are observed in autaptic GABAergic striatal neurons
|
|
|
• in layer 2/3 pyramidal neurons of the somatosensory cortex
|
|
|
• mice show an increased prepulse inhibition at 78 and 82 dB prepulses at 8 weeks
|
respiratory system
|
|
• coinciding with weight loss, mice display a 42% reduction in tidal volume (and 45% reduction in minute volume)
|
|
|
• mice display frequent apneas of greater than 0.4 second durations, coincident with weight loss
|
|
|
• severe respiratory dysfunction is coincident with weight loss
|
|
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
Tg(Nes-cre)1Kln mutation
(4 available)
|
|
|
mortality/aging
behavior/neurological
|
|
• develop a stiff, uncoordinated gait
|
craniofacial
|
|
• frequently exhibit uneven wearing of the teeth
|
endocrine/exocrine glands
growth/size/body
|
|
• frequently exhibit uneven wearing of the teeth
|
reproductive system
skeleton
|
|
• frequently exhibit uneven wearing of the teeth
|
|
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
|
|
|
mortality/aging
|
N |
• no early mortality is observed in contrast to Mecp2-null animals
|
growth/size/body
|
|
• Background Sensitivity: a mild increase (animals are about 1 gram heavier) is observed relative to wild-type or F1 mutants from an FVB/N cross
|
behavior/neurological
|
|
• mice have a decreased startle response relative to wild-type
|
|
|
• Background Sensitivity: mice display impaired performance in coordination tasks like the rotating rod, hanging wire, and dowel walking tests
|
|
|
• mutants exhibit deficit in pain recognition rather than significant defect in pain sensitivity
|
|
|
• mice show increased latency in the hot plate assay
|
|
|
• mice show deficits in nest-building relative to wild-type, with fewer animals building or completing nests than wild-type animals over the same time period
|
|
|
• mice have altered social behavior and spend more time than wild-type animals interacting with an unfamiliar mouse or with a 'familiar' mouse that has been reintroduced into the cage
|
nervous system
|
|
• mice show decreased prepulse inhibition at 74 and 82 decibels compared to wild-type
|
|
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
|
|
|
mortality/aging
|
N |
• no early mortality is observed in contrast to Mecp2-null animals
|
behavior/neurological
|
N |
• Background Sensitivity: no overt abnormalities are observed; mutants do not exhibit impaired coordination in a variety of tests measured
• mice do not show overt abnormalities like tremor or limb grasping
|
|
|
• percentage of time spent freezing is elevated relative to wild-type when placed back into the conditioning chamber
|
|
|
• percentage of time spent freezing is elevated relative to wild-type when re-exposure to a previously experienced cue
|
|
|
• mice show decrease anxiety-related behavior in open field assays than wild-type mice
|
|
|
• increased number of vertical explorations is observed compared to wild-type; this is indicative of reduced anxiety
|
|
|
• mutants exhibit deficit in pain recognition rather than significant defect in pain sensitivity
|
|
|
• mice have altered social behavior and spend more time than wild-type animals interacting with an unfamiliar mouse or with a 'familiar' mouse that has been reintroduced into the cage
|
nervous system
|
|
• mice show decreased prepulse inhibition compared to wild-type
|
respiratory system
|
|
• at 4 months, respiratory pattern is qualitatively different than in wild-type; coefficient of variability of the respiratory rhythm is higher than in wild-type
|
|
|
• increase in apnea incidence (39.5/hour) is observed compared to wild-type (5.8/hour)
|
growth/size/body
|
N |
• Background Sensitivity: no size difference is detected relative to wild-type, unlike mice on the C57BL/6 background
|
Allelic
Composition |
Mecp2tm1Bird/Y
|
|
Genetic
Background |
involves: 129P2/OlaHsd * C57BL/6J * FVB/N |
|
| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Mecp2tm1Bird mutation
(2 available);
any
Mecp2 mutation
(38 available)
|
|
|
mortality/aging
|
N |
• mice do not show premature lethality
|
respiratory system
|
N |
• mice do not exhibit apneas
|
Analysis Tools