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Fig. 1 (a-g): Rspo2 is expressed in the LRO and is required for LR specification.
a Scheme of dorso-posterior explants from Xenopus St. 19 neurula harboring the left-right organizer (LRO). A anterior, P posterior, R right and L left. b (Left) Whole-mount in situ hybridization (WISH) of rspo2, nodal and dand5 in the LRO. LEC, lateral-endodermal crest; CBC, circumblastoporal collar. Scale bar, 100m. (Right) Cartoons illustrating the ciliated LRO. Central motile cilia (black) generate leftward fluid flow that is sensed by immotile cilia (magenta). c Microinjection strategy for (dj). d Scheme of the morphologic analysis. Dashed square, ventral view of heart and intestine from Xenopus tailbud (St. 42) presented in (ej). e Representative images of normal and reversed heart in Xenopus tailbuds. OFT outflow tract, V ventricle. Scale bar, 100m. R right, L left. f, g Quantification of heart looping in Xenopus tailbuds injected as indicated. |