Daam1 knockdown alters morphogenesis of the pronephric tubules and duct and can be rescued by flDaam1 as assessed by markers of the mature pronephros in Xenopus. (A) Diagram of Xenopus pronephric kidney showing positions of lectin staining in the proximal tubules (green) and 4A6 antibody staining in the distal tubules and collecting duct (red). (B through F) The left V2 blastomere of eight-cell stage embryos was injected with 20 ng of Std MO or Daam1 MO. Embryos developed until stage 38 to 40 and were analyzed for lectin, 4A6 antibody, and 12/101 antibody staining within the proximal tubules, distal tubules/duct, and somites, respectively, on their injected (left) side as compared with their uninjected (right) side. (B) The PNI is greater in Daam1-MO-injected animals than in Std-MO-injected animals. (C) The fraction with reduced proximal tubule and distal tubule/duct marker staining on the injected side as compared with the uninjected side for Daam1-MO-injected animals is greater than that for Std-MO-injected controls, whereas the fraction with reduced somite marker staining on the injected side as compared with the uninjected side for Daam1-MO-injected animals was similar to that of Std-MO-injected controls. (D) Injected sides of Std-MO-injected animals do not have reduced proximal tubule marker staining, whereas injected sides of Daam1-MO-injected animals have significantly reduced proximal tubule marker staining. Bar is 100 μm. (E) Injected sides of Std-MO-injected animals do not have reduced distal tubule and duct marker staining, whereas injected sides of Daam1-MO-injected animals have significantly reduced distal tubule and duct marker staining. Bar is 100 μm. (F) Injected sides of Std-MO- or Daam1-MO-injected animals do not have reduced somite marker staining. Bar is 250 μm. (G through M) The left V2 blastomere of eight-cell stage embryos was injected with 20 ng Std MO + 1 ng β-gal, 20 ng Daam1 MO + 1 ng β-gal, or 20 ng Daam1 MO + 1 ng flDaam1. Embryos developed until stage 38 to 40 and were analyzed for lectin, 4A6 antibody, and 12/101 antibody staining within the proximal tubules, distal tubules/duct, and somites, respectively, on their injected (left) side as compared with their uninjected (right) side. (G) The PNI is greater in Daam1-MO + β-gal-injected animals than in Std-MO + β-gal embryos or Daam1-MO + flDaam1-injected rescue animals. (H) The fraction with reduced proximal tubule marker staining on the injected side as compared with the uninjected side for Daam1 MO + β-gal-injected animals was greater than that of Std-MO + β-gal-injected controls. This reduction in proximal tubule staining seen in Daam1 MO + β-gal animals was rescued in Daam1-MO + flDaam1-injected animals. (I) The fraction with reduced distal tubule and duct marker staining on the injected side as compared with the uninjected side for Daam1-MO + β-gal-injected animals was greater than that of the Std-MO + β-gal-injected controls. This reduction in distal tubule and duct staining seen in Daam1 MO + β-gal animals was rescued in Daam1 MO + flDaam1-injected animals. (J) The fraction with reduced somite marker staining on the injected side as compared with the uninjected side for was similar for Std-MO + β-gal-, Daam1-MO + β-gal-, and Daam1-MO + flDaam1-injected animals. (K) Injected sides of Std-MO + β-gal-injected animals do not have reduced proximal tubule marker staining, whereas injected sides of Daam1-MO + β-gal injected animals have significantly reduced proximal tubule marker staining. This loss of proximal tubule marker staining is rescued in Daam1-MO + flDaam1-injected animals. Bar is 100 μm. (L) Injected sides of Std-MO + β-gal-injected animals do not have reduced distal tubule and duct marker staining, whereas injected sides of Daam1-MO + β-gal-injected animals have significantly reduced distal tubule and duct marker staining. This loss of staining with the distal tubule and duct marker is rescued in Daam1-MO + flDaam1-injected animals. Bar is 100 μm. (M) Injected sides of Std-MO + β-gal-, Daam1-MO + β-gal-, and the Daam1-MO + flDaam1-injected animals do not have reduced somite marker staining. Bar is 250 μm.