(A–C): Organ position in Xenopus embryos at stage 45. A) Wildtype organ situs in an untreated embryo, with the stomach (yellow arrow) coiling to the embryo’s left, the gall bladder (green arrow) on the embryo’s right, and the heart apex (red arrow) located on the embryo’s left. B) Heterotaxic organ situs in an embryo injected with DNaPKC. In a small percentage of embryos, only the position of the gall bladder is affected. C) Situs inversus observed in an embryo injected with DNPar6, marked by the inverted position of all three organs. D) Schematic showing the wildtype position of three asymmetric organs, the heart (red), stomach (yellow), and gall bladder (green).