Fig. 4. Pax2 mutant mesenchyme is unresponsive to induction. Metanephric mesenchymes (arrows) from Pax2 and Ret homozygous null embryos were isolated at E11 and co-cultured with E11 dorsal spinal cord (sc). (A) Phase contrast micrographs taken at 0, 24 and 72 hours post explant. Note the disappearance of Pax2 mutant mesenchyme, whereas the Ret mesenchyme forms epithelial aggregates within 24 hours. (B) Whole-mount immunostaining for E-cadherin and Pax2 as indicated. Tubules derived from the Ret mesenchyme show prominent expression of E-cadherin. What little remains of the Pax2 mutant mesenchyme is negative for E-cadherin. Scale bars: 500 µm.
