Fig. 2.

Secondary trunks resulting from ectopic chordin expression contained pronephros. One posterior blastomere of four- to eight-cell stage embryos was injected with chordin mRNA. A,B: Embryos analyzed form muscle and notochord using immunocytochemistry 12/101 and Tor70 antibodies. C,D: At stage 33/34, some embryos were analyzed for pronephros (blue, yellow arrowhead) using in situ hybridization to detect XSMP-30 expression and analyzed for somitic muscle (brown, red arrowhead) formation immunocytochemistry with the 12/101 antibody. E,F: Some embryos were analyzed at stage 38-40 for pronephric duct formation using the 4A6 antibodies. The black arrows indicate pronephric ducts in the secondary and primary axis. G: Injected embryos analyzed at stage 38 for pronephric tubule formation using the 3G8 antibodies. The black arrows indicate pronephric tubules in the secondary and primary axis. H: One posterior blastomere of four- to eight-cell stage embryos was injected with noggin mRNA. Embryos were analyzed at stage 38-40 for pronephric duct formation using the 4A6 antibodies. The black arrows indicate pronephric ducts in the secondary and primary axis.