gpr22 deregulation results in defective LR patterning.
(A) Ventral or (B, C) dorsal views with anterior to the top of embryos at (A, B) 4 dpf or (C) 20 somite stage. (A) Transgenic embryos expressing GFP under control of the cmlc2 promoter. In contrast to water controls, gpr22 morphants show (from top to bottom) normal, absent, reversed or bicardial cardiac looping. Co-injection of 0.2 mM gpr22 MO and 100 pg/nl gpr22 RNA partially rescues the randomized cardiac looping (last panel). (B) WISH for foxa3. The liver of water control embryos develops at the left side of the embryo. In contrast, the position of the liver in embryos injected with 0.2 mM gpr22 MO is randomized (straight line). (C) WISH for southpaw (spaw). gpr22 morphants show randomized expression of the early left-specific LPM marker southpaw (straight line). (D) Quantifications of the heart or (E) liver/gut phenotype. MO = morpholino, V = ventricle, A = atrium, dpf = days post-fertilization, n = number of analyzed embryos, GFP = green fluorescence protein, cmlc2 = cardiac myosin light chain type 2, LR = left-right, WISH = whole mount in situ hybridization, LPM = lateral plate mesoderm.