Volume 30, Issue 5 pp. 585-595
Main Articles

The sarcolemma in the largemyd mouse

Patrick W. Reed PhD

Patrick W. Reed PhD

Department of Physiology, University of Maryland School of Medicine, 660 West Redwood Street, Baltimore, Maryland 21201, USA

Search for more papers by this author
Katherine D. Mathews MD

Katherine D. Mathews MD

Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA

Search for more papers by this author
Kathleen A. Mills PhD

Kathleen A. Mills PhD

Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA

Search for more papers by this author
Robert J. Bloch PhD

Corresponding Author

Robert J. Bloch PhD

Department of Physiology, University of Maryland School of Medicine, 660 West Redwood Street, Baltimore, Maryland 21201, USA

Department of Physiology, University of Maryland School of Medicine, 660 West Redwood Street, Baltimore, Maryland 21201, USASearch for more papers by this author
First published: 07 September 2004
Citations: 14

Abstract

In the Largemyd mouse, dystroglycan is incompletely glycosylated and thus cannot bind its extracellular ligands, causing a muscular dystrophy that is usually lethal in early adulthood. We show that the Largemyd mutation alters the composition and organization of the sarcolemma of fast-twitch skeletal muscle fibers in young adult mice. Costameres at the sarcolemma of the tibialis anterior muscle of Largemyd mice contain reduced levels of several membrane cytoskeletal proteins, including dystrophin and β-spectrin. In the quadriceps, longitudinally oriented costameric structures tend to become thickened and branched. More strikingly, proteins of the dystrophin complex present between costameres in controls are absent from Largemyd muscles. We propose that the absence of the dystrophin complex from these regions destabilizes the sarcolemma of the Largemyd mouse and thereby contributes to the severity of its muscular dystrophy. Thus, the positioning of sarcolemmal proteins may have a profound effect on the health of skeletal muscle. Muscle Nerve, 2004

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.

click me