Basic mechanisms of cardiac gene expression.

Although the physiological properties of the myocardium and their dynamic character have been the focus of intense research during the past three decades, the biochemical and molecular correlates underlying cardiac development and performance have, until recently, remained poorly understood. The development of modern biology has provided the necessary tools to undertake the study of the mechanisms involved in cardiac development and to understand the basis for important clinical and experimental problems in cardiovascular physiology. Most of the gene encoding contractile proteins have been cloned and characterized. The availability of molecular probes and the ability to introduce genes into individual cell types and tissues of living animals are the most important breakthroughs of molecular and cell biology. This permits not only analysis of basic mechanisms of gene expression but has also significant practical applications for gene therapy. It is now possible to analyse the role of different regulatory gene sequences and identify their corresponding transactive factors. In addition direct gene injection makes it possible to study gene expression in a natural context, under conditions that are physiologically relevant and controllable.