Project description:Mitochondrial calcium is an important second-messenger controlling fight-or-flight responses in the heart. The molecular identity of MCU (Mitochondrial Calcium Uniporter) was recently discovered allowing us to test this hypothesis in vivo by expressing a myocardial delimited dominant negative form of MCU. We queried mRNA expression changes induced by dominant negative MCU expression in the heart. Neonatal (< 24 h) and 6 week old hearts were harvested from mice expressing the dominant negative MCU construct or wild-type littermates.