Phenotypes Associated with This Genotype

Genotype
MGI:5426828

• Allelic Composition: Tg(ACTA1-cre/ERT2)97.16Mtz/0; Tg(CAG-DMPK*)1323Coop/0
• Genetic Background: involves: FVB

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

behavior/neurological

abnormal motor capabilities/coordination/movement ( J:132154 )

• on a graded treadmill protocol, mutants treated with tamoxifen show a decrease in the time of drop off from the treadmill compared to controls

abnormal locomotor behavior ( J:132154 )

• by 4 weeks after tamoxifen administration, 70% of mutants show reduced mobility

abnormal gait ( J:132154 )

• by 4 weeks after tamoxifen administration, 70% of mutants show abnormal gait

muscle

abnormal skeletal muscle fiber morphology ( J:132154 )

• mutants treated with tamoxifen exhibit increased numbers of smaller myocytes, scattered basophilic fibers, acute myofibrillar degeneration with significant numbers of necrotic fibers and many fibers with basophilic cytoplasm and central nuclei consistent with regeneration

• four weeks after tamoxifen administration, mutants show a loss in fibers expressing solely slow twitch myosin and an increase in the number of fibers showing simultaneous expression of slow and fast twitch myosin isoforms

decreased skeletal muscle size ( J:132154 )

• by 4 weeks after tamoxifen administration, mutants show a severe reduction in muscle size

• muscle wasting progressively worsens with a 15% reduction in diameter by 4 weeks after tamoxifen administration

skeletal muscle degeneration ( J:132154 )

• mutants treated with tamoxifen exhibit severe and progressive skeletal muscle wasting and degeneration

skeletal muscle fibrosis ( J:132154 )

• mutants treated with tamoxifen exhibit focal regions with increased fibrosis in skeletal muscle

impaired muscle relaxation ( J:132154 )

• mutants treated with tamoxifen to induce cre-recombination exhibit sustained myotonia, with waxing and waning myotonic runs noted on electromyogram

• mutants not treated with tamoxifen also develop myotonia, indicating basal leakiness of the transgene, however they do not show overt skeletal muscle wasting, histological abnormalities or muscle dysfunction as do tamoxifen treated mutants

skeleton

kyphosis ( J:132154 )

• by 4 weeks after tamoxifen administration, 70% of mutants show kyphosis

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
myotonic dystrophy type 1		DOID:11722	OMIM:160900	J:132154