Origin of the smooth muscle cells during murine lung development

Pulmonary smooth muscle cells (SMC) are extremely important for normal respiratory function. Impaired formation or function of SMCs lead to organ failure. The origin of lung airway and vascular SMCs is recently emerging. Using Fgf10LacZ enhancer trap line, we were the first to show that Fgf10-expressing cells could serve as progenitors for the airway SMCs. Our recent lineage tracing data using the Fgf10CreERT2 knock in line showed that only around 3 – 18% of the Fgf10-expressing cells labeled before E13.5 contribute to the SMC (both vascular and airway). However, after E14.5, these progenitor cells are no longer…