Absence of developmental and unconventional myosin heavy chain in human suprahyoid muscles
Copyright © 2013 Wiley Periodicals, Inc., a Wiley company
- Accepted manuscript online: 8 JUL 2013 07:10AM EST
- Manuscript Accepted: 27 JUN 2013
- Manuscript Revised: 25 JUN 2013
- Manuscript Received: 28 DEC 2012
- National Institute on Deafness and Other Communication Disorders. Grant Number: DC005017
- National Center for Research Resources, NIH. Grant Number: RR00169
- myosin heavy chain;
Introduction: Contradictory reports of the myosin heavy chain (MHC) composition of adult human suprahyoid muscles leave unresolved the extent to which these muscles express developmental and unconventional MHC.
Methods: By immunohistochemistry, separation SDS-PAGE-Coomassie, separation SDS-PAGE-Western blot, and mRNA PCR, we tested for conventional MHCI, MHCIIA, MHCIIX, developmental MHC embryonic and MHC neonatal, and unconventional MHC alpha-cardiac, MHC extraocular, and MHC slow tonic in adult human anterior digastric (AD), geniohyoid (GH) and mylohyoid (MH) muscles.
Results: By separation SDS-PAGE-Coomassie and Western blot only conventional MHC are present. By immunohistochemistry all muscle fibers are positive for MHCI, MHCIIA, or MHCIIX, and fewer than 4 fibers/mm2 are positive for developmental or unconventional MHC. By PCR, mRNA of MHCI and MHCIIA dominate, with sporadically detectable MHC alpha-cardiac and without detectable mRNA of other developmental and unconventional MHC.
Discussion: We conclude that human suprahyoid muscles AD, GH and MH are composed almost exclusively of conventional MHC isoforms. © 2013 Wiley Periodicals, Inc.