Figure 4.
Effect of Drug Treatment and Microinjection of Overexpressed Formin on Chirality in the Frog
(A) Embryos were treated with DMSO, CK-666, or SMIFH2 at the concentrations indicated, allowed to develop, and scored for visceral organ chirality at stage 45.
(B) Embryos were injected into the animal pole with mRNA encoding mouse dia1 formin and scored for visceral organ situs at stage 45. Images: Examples of organ situs for experimental microinjection with wild-type mouse dia1 mRNA. The control shows a wild-type (situs solitus) tadpole, ventral view, demonstrating the normal arrangement of the stomach (yellow arrowhead), heart apex (red arrowhead), and gall bladder (green arrowhead). Heterotaxic tadpoles (ventral view) resulting from formin overexpression show reversal of all three organs, i.e., situs inversus; the gut position and looping and gall bladder; or the heart.