Fig. 7.

Ex vivo culture of salt-stressed Bdkrb2^−/− metanephroi. A: E12.5 metanephroi were harvested from Pax2-GFP;Bdkrb2^+/+, Pax2-GFP;Bdkrb2^+/−, and Pax2-GFP;Bdkrb2^−/− littermates and grown in culture (n = 12–18/group). The intensity of GFP fluorescence, a surrogate of Pax2 promoter activity and expression, was recorded at times 0, 24, and 48 h. Bdkrb2^−/− metanephroi are smaller than the heterozygous and homozygous null mutants and maintain lower GFP fluorescence intensity ex vivo. B: quantitative measurement of GFP fluorescence reveals that although GFP pixel intensity increases in all groups during 24–48 h in the absence of the intrauterine salt stressor, the reduction in GFP intensity remains significantly lower in the Bdkrb2^−/− metanephroi.