Figure 4.

Nascent PPFs are lateral-plate derived and the target of diaphragm muscle progenitors and phrenic nerve. At E10.0 just forming PPFs are a medial extension of lateral plate, as labeled by Prx1Cre^Tg/+;Rosa26^mTmG/+ (and outlined in orange) and are the target of muscle progenitors migrating from somites C3–C5 (outlined in yellow, as extrapolated from Fig 3C) and phrenic nerve axons. Forelimb is outlined in white. Scale bar = 100um. 3-dimensional movie in Supplemental Movie 7.