Skeletal muscles display a remarkable diversity in their arrangement of fibers into fascicles and in their patterns of innervation, depending on functional requirements and species differences. Most human muscle fascicles, despite their great length, consist of fibers that extend continuously from one tendon to the other with a single nerve endplate band. Other mammalian muscles have multiple endplate bands and fibers that do not insert into both tendons but terminate intrafascicularly. We investigated whether these alternate structural features may dictate different modes of cell hypertrophy in two mouse gracilis muscles, in response to expression of a muscle-specific insulin-like growth factor (IGF)-1 transgene (mIGF-1) or to chronic exercise. Both hypertrophic stimuli independently activated GATA-2 expression and increased muscle cross-sectional area in both muscle types, with additive effects in exercising myosin light chain/mIGF transgenic mice, but without increasing fiber number. In singly innervated gracilis posterior muscle, hypertrophy was characterized by a greater average diameter of individual fibers, and centralized nuclei. In contrast, hypertrophic gracilis anterior muscle, which is multiply innervated, contained longer muscle fibers, with no increase in average diameter, or in centralized nuclei. Different modes of muscle hypertrophy in domestic and laboratory animals have important implications for building appropriate models of human neuromuscular disease.
Skip Nav Destination
Article navigation
18 February 2002
Article|
February 11 2002
Different modes of hypertrophy in skeletal muscle fibers
Angelika C. Paul,
Angelika C. Paul
Mouse Biology Program, European Molecular Biology Laboratory, 00016 Monterotondo-Scalo, Rome, Italy
Search for other works by this author on:
Nadia Rosenthal
Nadia Rosenthal
Mouse Biology Program, European Molecular Biology Laboratory, 00016 Monterotondo-Scalo, Rome, Italy
Search for other works by this author on:
Angelika C. Paul
Mouse Biology Program, European Molecular Biology Laboratory, 00016 Monterotondo-Scalo, Rome, Italy
Nadia Rosenthal
Mouse Biology Program, European Molecular Biology Laboratory, 00016 Monterotondo-Scalo, Rome, Italy
Address correspondence to Nadia Rosenthal, Mouse Biology Program, European Molecular Biology Laboratory, Via Ramarini 32, 00016 Monterotondo-Scalo, Rome, Italy. Tel.: (39) 06-90091 241. Fax: (39) 06-90091 272. E-mail: [email protected]
*
Abbreviations used in this paper: AChE, acetylcholinesterase; EDL, extensor digitorum longus; EX, exercised; IGF, insulin-like growth factor; MLC, myosin light chain; WT, wild-type.
Received:
May 31 2001
Revision Received:
December 26 2001
Accepted:
January 08 2002
Online ISSN: 1540-8140
Print ISSN: 0021-9525
The Rockefeller University Press
2002
J Cell Biol (2002) 156 (4): 751–760.
Article history
Received:
May 31 2001
Revision Received:
December 26 2001
Accepted:
January 08 2002
Citation
Angelika C. Paul, Nadia Rosenthal; Different modes of hypertrophy in skeletal muscle fibers . J Cell Biol 18 February 2002; 156 (4): 751–760. doi: https://doi.org/10.1083/jcb.200105147
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionEmail alerts
Advertisement
Advertisement