Mouse transgenic lines that selectively label Type I, Type IIA, and Types IIX+B skeletal muscle fibers.

Journal Article (Letter)

Skeletal muscle fibers vary in contractile and metabolic properties. Four main fiber types are present in mammalian trunk and limb muscles; they are called I, IIA, IIX, and IIB, ranging from slowest- to fastest-contracting. Individual muscles contain stereotyped proportions of two or more fiber types. Fiber type is determined by a combination of nerve-dependent and -independent influences, leading to formation of "homogeneous motor units" in which all branches of a single motor neuron form synapses on fibers of a single type. Fiber type composition of muscles can be altered in adulthood by multiple factors including exercise, denervation, hormones, and aging. To facilitate analysis of muscle development, plasticity, and innervation, we generated transgenic mouse lines in which Type I, Type IIA, and Type IIX+B fibers can be selectively labeled with distinguishable fluorophores. We demonstrate their use for motor unit reconstruction and live imaging of nerve-dependent alterations in fiber type.

Full Text

Duke Authors

Cited Authors

  • Chakkalakal, JV; Kuang, S; Buffelli, M; Lichtman, JW; Sanes, JR

Published Date

  • January 2012

Published In

Volume / Issue

  • 50 / 1

Start / End Page

  • 50 - 58

PubMed ID

  • 21898764

Pubmed Central ID

  • PMC3969845

Electronic International Standard Serial Number (EISSN)

  • 1526-968X

Digital Object Identifier (DOI)

  • 10.1002/dvg.20794


  • eng

Conference Location

  • United States