Fate map of early avian cardiac progenitor cells

Cardiogenic fate maps are used to address questions on commitment, differen tiation, morphogenesis and organogenesis of the heart. Recently, the accura cy of classical cardiogenic fate maps has been questioned, raising concerns about the conclusions drawn in studies based on these maps. We present acc urate fate maps of the heart-forming region (HFR) in avian embryos and show that the putative cardiogenic molecular markers Bmp2 and Nkx2.5 do not gov ern the boundaries of the HFR as suggested in the literature. Moreover, thi s paper presents the first fate map of the HFR at stage 4 and addresses a v oid in the literature concerning rostrocaudal patterning of heart cells bet ween stages 4 and 8.