ABSTRACT
The lung is a complex organ that requires interactions between tissues and cells of various lineages to effi ciently perform the task of gas exchange. Here we review the general development of the lung, focusing on what is known about the embryonic progenitor lineages that give rise to the mature cell types found in the adult lungs. While the epithelial lineages have been well characterized in terms of the major contributing cell populations, much less is understood about the mesenchymal development, including the lineages that give rise to the vascular, smooth muscle, and lung haematopoietic cells. Adult multipotent lineages and their role in maintenance, repair, and regeneration will also be examined. Characterization of these adult populations is important for understanding the potential of the various lung lineages for differentiation into functional cells that could be used to regenerate the lung.
