RT Journal Article
SR Electronic
T1 Regulation of Chamber-Specific Gene Expression in the Developing Heart by <em>Irx4</em>
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1161
OP 1164
DO 10.1126/science.283.5405.1161
VO 283
IS 5405
A1 Bao, Zheng-Zheng
A1 Bruneau, Benoit G.
A1 Seidman, J. G.
A1 Seidman, Christine E.
A1 Cepko, Constance L.
YR 1999
UL http://science.sciencemag.org/content/283/5405/1161.abstract
AB The vertebrate heart consists of two types of chambers, the atria and the ventricles, which differ in their contractile and electrophysiological properties. Little is known of the molecular mechanisms by which these chambers are specified during embryogenesis. Here a chicken iroquois-related homeobox gene,Irx4, was identified that has a ventricle-restricted expression pattern at all stages of heart development. Irx4 protein was shown to regulate the chamber-specific expression of myosin isoforms by activating the expression of the ventricle myosin heavy chain–1 (VMHC1) and suppressing the expression of the atrial myosin heavy chain–1 (AMHC1) in the ventricles. Thus, Irx4 may play a critical role in establishing chamber-specific gene expression in the developing heart.