Open AccessSegregation of cardiac and skeletal muscle-specific regulatory elements of the beta-myosin heavy chain gene.
Author(s) -
Hansjörg Rindt,
Stephanie Knotts,
Jeffrey Robbins
Publication year - 1995
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.92.5.1540
Subject(s) - chloramphenicol acetyltransferase , biology , skeletal muscle , transgene , gene expression , myosin , reporter gene , regulation of gene expression , cardiac muscle , gene , genetically modified mouse , microbiology and biotechnology , endocrinology , genetics
The beta-myosin heavy chain (beta-MyHC) gene is expressed in cardiac and slow skeletal muscles. To examine the regulatory sequences that are required for the gene's expression in the two compartments in vivo, we analyzed the expression pattern of a transgene consisting of the beta-MyHC gene 5' upstream region linked to the chloramphenicol acetyltransferase reporter gene. By using 5600 bp of 5' upstream region, the transgene was expressed at high levels in the slow skeletal muscles. Decreased levels of thyroid hormone led to the up-regulation of the transgene in both cardiac and skeletal muscles, mimicking the behavior of the endogenous beta-MyHC gene. After deleting the distal 5000 bp, the level of reporter gene expression was strongly reduced. However, decreased levels of thyroid hormone led to an 80-fold skeletal muscle-specific increase in transgene expression, even upon the ablation of a conserved cis-regulatory element termed MCAT, which under normal (euthyroid) conditions abolishes muscle-specific expression. In contrast, cardiac-specific induction was not detected with the deletion construct. These observations indicate that the cardiac and skeletal muscle regulatory elements can be functionally segregated on the beta-MyHC gene promoter.