Lineage-based primary muscle fiber type diversification independent of MEF2 and NFAT in chick embryos. J Muscle Res Cell Motil 2011 Mar;31(5-6):369-81
Date
02/04/2011Pubmed ID
21290171Pubmed Central ID
PMC3388508DOI
10.1007/s10974-011-9242-0Scopus ID
2-s2.0-79952315640 (requires institutional sign-in at Scopus site) 9 CitationsAbstract
Differences in primary avian skeletal muscle fiber types are based on myoblast cell lineages and independent of innervation. To understand the basis for this mode of myogenesis, embryonic myoblasts specifically committed to the formation of either fast or fast/slow muscle fiber types were isolated, characterized, and examined for their capacities to transcriptionally regulate the slow myosin heavy chain 2 (MyHC2) gene. Myogenic basic helix-loop-helix protein binding sites within the slow MyHC2 promoter were mutated and did not direct fast versus fast/slow muscle fiber type development. Using promoter analyses coupled with overexpression studies and transcriptional sensors, the roles of Nuclear Factor of Activated T cells (NFATc1), and MEF2A in regulation of the slow MyHC2 gene were determined. MEF2A activated the slow MyHC2 promoter in both fast and fast/slow primary muscle fibers. In contrast, NFATc1 repressed promoter activity. These results do not support the roles of MEF2 and NFAT as direct regulators of primary muscle fiber type differences. Rather, the results reflect intrinsic differences in the modes of regulation of the slow MyHC2 gene in primary muscle fiber types.
Author List
Theobald J, DiMario JXAuthor
Jillian Lee Theobald MD, PhD Associate Professor in the Emergency Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCell Lineage
Chick Embryo
MEF2 Transcription Factors
Muscle Fibers, Skeletal
Myoblasts
Myogenic Regulatory Factors
NFATC Transcription Factors