Optogenetic mapping of embryonic cardiac pacemaker cells

Congenital heart defects (CHDs) constitute a substantial proportion of all congenital anomalies worldwide and are commonly observed in newborns. To improve CHD management, it is crucial to understand how molecular, genetic, mechanical, and electrical processes interact during embryonic development. For that, genetic mouse models are invaluable to understanding normal heart development and the mechanisms underlying CHD with well-established genome manipulation tools and thousands of genetic lines. While genetic and molecular factors governing heart development and disease have been well studied, the role of the early heartbeat and conduction is less understood due to the lack of tools for imaging and controlling cardiodynamics in mouse embryos. Here, we present an optogenetic platform enabling real-time mapping of mouse embryonic cardiac pacemakers, providing a unique tool for studying early conduction development and potentially CHD.