Conditional transgenics

Transgenic mice are important experimental systems for understanding the regulation of gene expression and the function of various gene products within the complex environment of an intact organism. Recombinant genes are introduced into the mouse embryo and their patterns of expression or phenotypic effects are examined. Although current technology permits one to target expression of the transgene to many distinct cell types, such as the cardiac myocyte, many experimental models require that gene expression be responsive to additional levels of control-a paradigm known as "conditional transgene expression." Here, we describe the rationale for conditional transgenics, examine the systems that have been utilized to achieve highly regulated gene expression in vivo, and consider how these new experimental approaches may improve our understanding of cardiovascular function and pathology.