Fig. 5

Fig. 5 Bifid hearts are each associated with their own proepicardial organ. Face views of buffer-injected (A) and milMO-injected (B) embryos stained with MF20 against myosin heavy chain (brown) and wt1 to mark the PEO (blue). A PEO cluster is visible at near the AV junction in buffer-injected embryos (arrow in panel A) while each heart in the milMO embryo is associated with a cluster of wt1-positive PEO (arrows in panel B). (C) Dorsal and (D) dorsolateral views on embryos injected with casMO. The nephric wt1 expression is indicated by the arrowheads and lies ventral to the anterior somites stained with MF20 (brown). Large, diffuse clusters of wt1 cells can be seen in the lateral positions (arrows). Dorsal views are shown because these cells fail to reach their more ventral positions next to the heart, seen here below the plane of focus in brown (asterisk). Anterior is to the left in panels C and D.