Figure 4.

Aberrant expression of coronary vessel and myocardial transcripts. (A) Staining of E12.5 wild-type (+/+) and mutant (ki/ki) hearts with an α-Flk-1 antibody (dorsal view). Staining of the mutant is vastly reduced within the heart, but lung tissue stained with equal intensity. (B) Immunostaining of wild-type and mutant hearts at E12.5 using the α-ICAM-2 antibody (dorsal view). Note the absence of a well-developed vascular tree in the mutant heart. (C) Whole-mount RNA in situ staining of eHand in E11.5 hearts. eHand expression is down-regulated in the outer myocardial layer (white arrows), whereas there is more intense staining in the outflow tract of the mutant (dark arrows). Note that the direction of the outflow tract relative to the heart is altered in the mutant, consistent with the pathological findings.