Fig. 5. Repressed Phox2b and Th expression in Gata3 mutant chromaffin cells. Whole-mount X-gal staining (A-C), HE staining (D-F), anti-Phox2b, anti-Th and anti-chromogranin A staining (G-O) on adrenal gland sections of E18.5 control (A,D,G,J,M), Gata3 mutant embryos bearing Tg^hDBH-G3 (B,E,H,K,N) or no transgene (C,F,I,L,O). ß-Gal⁺ adrenal medulla (arrow) and organ of Zuckerkandl (arrowhead) is significantly smaller in the pharmacologically rescued E18.5 Gata^Z/- embryos (C). The size of adrenal medullary region is reduced in the pharmacologically rescued Gata3^-/- embryos in the HE sections (F). Expression of Phox2b, Th and chromogranin A is virtually absent in the Gata3^-/- embryos (I,L,O). In the Tg-rescued homozygous mutant embryos, the adrenal chromaffin cell population and the expression of above-mentioned SA markers are partially restored (B,E,H,K,N). The control animals used were Gata3^Z/+ (A) and Gata3^+/+ (wild-type) littermates (D,G,J,M). (P-R) Co-localization of transgenic eGFP and restored Th expression in Gata3^Z/-:Tg^hDBH-G3-rescued mutants. (S) Relative Th- and Phox2b-positive chromaffin cell areas in serial sections of adrenal glands. At least four serial sections of each of the four examined ganglia from different two embryos of each genotype were evaluated. Data are presented as mean±s.e.m. Scale bars: 100 µm. The statistical significance of the differences between Gata3^-/-:Tg^hDBH-G3 and Gata3^-/- are indicated (^*P<0.05; ^**P<0.01; Student's t-test).