Fig. 6. Tak1
/
embryos have defects in vascular smooth
muscle. To visualize smooth muscle, embryos were stained by
immunohistochemistry using an antibody to SMA (purple staining in all panels).
(A-C) E9.5 embryos. (D-F) E10.5 embryos. At E9.5 the Tak1+/
control embryo has a layer of SMA-expressing cells beginning along the dorsal
aorta (A, arrowheads). The class II (B) and class I
Tak1
/
(C) embryos have no SMA expression along
their dorsal aorta (arrowheads). At E10.5, the Tak1+/
control
embryo (D) shows a continuous layer of SMA expression all along the
dorsal aorta (arrowheads). The more severely affected
Tak1
/
embryo (F) has a complete absence of SMA
expression in the dorsal aorta (arrowheads) and the less severely affected
embryo (E) has only a few loosely associated expressing cells
(arrowheads). All the embryos display staining of the somites and heart. S,
somites; O, otic vesicle; H, heart.