Publisher Summary This chapter discusses the findings that preceded and led to the
identification of this progenitor cell population, and different molecular and genetic
experiments evaluating the overlap between the first and second heart fields and their
contributions to the definitive heart. It also examines extensive new data that has led to
molecular insights into the transcription factors and signaling pathways that regulate second
heart field deployment, and considers the biomedical significance of the second heart field …

During cardiac looping the heart tube elongates by addition of progenitor cells from adjacent
pharyngeal mesoderm to the arterial and venous poles. This cell population, termed the
second heart field, was first identified ten years ago and many studies in the intervening
decade have refined our understanding of how heart tube elongation takes place and
identified signaling pathways that regulate proliferation and differentiation during
progressive contribution of second heart field cells to the embryonic heart. It has also …