Mouse Genome Informatics
ot
    Mtm1tm1.1Jman/Y
involves: 129T1/Sv * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       

Clinical evaluation of muscle weakness in Mtm1tm1.1Jman/Y mice

mortality/aging
• hemizygous males are underrepresented ( 16.6% instead of the expected 25%) suggesting a certain degree of pre- or neonatal lethality, however no time of death was reported (J:81791)
• occurs at 59 +/- 19 days due to cachexia and respiratory insufficiency (J:81791)
(J:179741)

growth/size/body
• before death (J:81791)
• a progressive growth impairment compared to wild-type littermates reaching a 35% reduction of body weight by 57 days (J:81791)

behavior/neurological
• a progressive motor deficit (J:81791)
• a decreased muscular strength starting in the hindlimbs at 4-5 weeks (J:81791)
(J:179741)
• hindlimbs become completely paralyzed by 8 weeks (J:81791)

muscle
• altered emplacement of mitochondria (J:81791)
• myofibrillar disorganization with sarcomeric disarray and Z-ine streaming that may originated from ER dilations (J:81791)
• atrophy and loss of myofibrils (J:81791)
• frequently seen vacuoles do not contain cellular debris as observed in autophagic vacuoles (J:81791)
• a progressive amyotrophy (J:81791)
• presence of an abnormal central, peripheral, or anarchical pattern of oxidative enzyme activity in myofibers (J:81791)
(J:81791)
(J:179741)
• skeletal muscle demonstrated a generalized myopathy with fiber size variation, hypotrophy, and progressive accumulation of paracentral or central nuclei (J:81791)
• myogenesis is not delayed (J:81791)
• inflammatory infiltrates and fibrosis, generally present in dystrophic muscle, were absent (J:81791)
• neither necrotic nor apoptotic muscle fibers were seen (J:81791)

skeleton
• by 5-7 weeks (J:81791)

respiratory system
• by 8 weeks (J:81791)

Mouse Models of Human Disease
OMIM IDRef(s)
Myopathy, Centronuclear, X-Linked; CNMX 310400 J:81791