Transient Expression Of A Slow-tonic Mhc Isoform By Extrafusal Fibers In The Developing Rat

Title

Transient Expression Of A Slow-tonic Mhc Isoform By Extrafusal Fibers In The Developing Rat

Creator

Kucera J; Walro J M

Publisher

Anatomy and Embryology

Date

1993
1993-10

Description

ALD 19, a monoclonal antibody that recognizes the slow-tonic myosin heavy chain (MHC) isoform, has been used extensively as a marker for nuclear bag intrafusal fibers of muscle spindles in developing and adult rats. Extrafusal fibers of adult rat hindlimb muscles do not express slow-tonic MHC. However, while using ALD 19 to trace the fate of intrafusal fibers following neonatal denervation, we noted that some extrafusal fibers of neonates also bound this antibody. The immunolabeled extrafusal fibers were a subset of slow fibers located in the deep axial regions of crural muscles. The same fiber subset transiently displayed a weak affinity for ALD 19 during the first postnatal week in normal muscles. Denervation at birth increased the intensity of ALD 19 immunolabelling by these extrafusal fibers and extended the duration of the slow-tonic immunoreactivity into the 2nd postnatal week, after which expression diminished or ceased. Demonstration that some developing extrafusal fibers have a nerve-independent capacity for transiently expressing slow-tonic MHC, an MHC previously thought to be expressed only by intrafusal fibers, raises the possibility that both types of fiber originate from a subset of bipotential slow primary myotubes in rat hindlimbs.

Subject

Anatomy & Morphology; denervation; Developmental Biology; diversity; extrafusal fibers; intrafusal fibers; intrafusal muscle-fibers; monoclonal-antibody; motor innervation; muscle; myosin heavy-chain; neonatal rats; skeletal-muscle; slow-tonic myosin; spindles

Identifier

Format

Journal Article or Conference Abstract Publication

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Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

409-418

Issue

4

Volume

188

Citation

Kucera J; Walro J M, “Transient Expression Of A Slow-tonic Mhc Isoform By Extrafusal Fibers In The Developing Rat,” NEOMED Bibliography Database, accessed June 24, 2021, https://neomed.omeka.net/items/show/10585.

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