Promiscuous expression of myosin in myotonic dystrophy.
The pathologic changes in myotonic dystrophy (DM) skeletal muscle biopsies have been analyzed at both the histochemical and molecular level. A histochemical stain for pretyping single fibers in conjunction with sodium dodecyl sulphate-polyacrylamide gel electrophoresis allowed biochemical differences to be pinpointed in specific histochemical fiber types. These biochemical differences can be related to histochemical changes in fiber type observed in cross-section of the DM biopsies. Such changes included specific fiber type atrophy, hypertrophy, and disproportion. The pathogenesis of DM appears to be characterized by a large increase in the number of promiscuous fibers, that is, those fibers that express both fast and slow myosins. This promiscuity, which is rare in control muscle (less than 2%), is also prevalent at high levels in some family members at risk for DM. The observed promiscuity, although probably not a primary effect of DM, appears to be linked to the histochemical changes in fiber type observed in the DM biopsies.
G E
GE
Moore
A D
AD
Roses
M A
MA
Pericak-Vance
W E
WE
Garrett
F H
FH
Schachat
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D008297:Male; D009132:Muscles / Q000032:analysis* / Q000378:metabolism / Q000473:pathology; D009218:Myosins / Q000032:analysis*; D009223:Myotonic Dystrophy / Q000378:metabolism* / Q000473:pathology; D012967:Sodium Dodecyl Sulfate
D012967:Sodium Dodecyl Sulfate; D009218:Myosins