The myotonic mouse mutant ADR: physiological and histochemical properties of muscle.

The myotonic mouse mutant ADR: electrophysiology of the muscle fiber.

The hereditary neuromuscular syndrome of the mouse, "arrested development of righting response" (ADR), is characterized by after-contractions of skeletal muscle. In order to analyze the etiology of this hereditary defect, mutant and wildtype muscle fibers were studied by intracellular recording. Direct stimulation of ADR muscle fibers elicited runs of action potentials of 1-5 seconds duration, ...

Activation of the MEF2 transcription factor in skeletal muscles from myotonic mice.

Becker syndrome, a recessive nondystrophic myotonia caused by mutations in the chloride channel 1 gene (CLCN1), is characterized by delayed muscle relaxation after contraction. The ADR (arrested development of righting response) mouse is an animal model for Becker syndrome. Skeletal muscles from ADR myotonic animals show an increased number of oxidative fibers with a lack of glycolytic fibers a...

Ultrastructural, Histochemical and Immunohistochemical Studies on Muscle Lesions of Myotonic Dystrophy-like Myopathy in a Mutant Lwc Strain of Japanese Quails

Identification of secondary effects of hyperexcitability by proteomic profiling of myotonic mouse muscle.

Myotonia is a symptom of various genetic and acquired skeletal muscular disorders and is characterized by hyperexcitability of the sarcolemma. Here, we have performed a comparative proteomic study of the genetic mouse models ADR, MTO and MTO*5J of human congenital myotonia in order to determine myotonia-specific changes in the global protein complement of gastrocnemius muscle. Proteomic analyse...

A muscleblind knockout model for myotonic dystrophy.

The neuromuscular disease myotonic dystrophy (DM) is caused by microsatellite repeat expansions at two different genomic loci. Mutant DM transcripts are retained in the nucleus together with the muscleblind (Mbnl) proteins, and these abnormal RNAs somehow interfere with pre-mRNA splicing regulation. Here, we show that disruption of the mouse Mbnl1 gene leads to muscle, eye, and RNA splicing abn...