Detection of X-gal-positive signals in Nolz-1-expressing urogenital organs of UREB-LacZ embryos.

A: By whole-mount staining, X-gal-positive signals are detected in the urogenital duct (arrow), ureteric tubules (ur) and stomach (sto) of E12.5 line #81 embryos. B–C: Many X-gal+/Nolz-1+ cells (arrows in C, D) were detected in some renal tubules of E13.5 kidney (k). The boxed regions in B are shown at high magnification in C, D. E–L: Expressions of LacZ (E, F, I, J) and Nolz-1 mRNAs (G, H, K, L) in transverse sections of urogenital organs of E13.5 line #81 embryos. The bracketed regions in E, G, I, K are shown at high magnification in F, H, J, L, respectively. M–P: Double labeling of LacZ mRNA (purple) and Nolz-1 protein (brown). LacZ and Nolz-1 mRNAs are both detected in the genital ridge (arrow) and genital duct (arrowhead) (see also arrow and arrowhead in F, H). Many LacZ+/Nolz-1+ cells are detected in these genital tissues (M). LacZ mRNA is also detected in the adrenal gland (ad, E) and stomach (sto, E) of UREB-LacZ embryo. LacZ and Nolz-1 co-expressing cells in stomach are detected (arrows, N). In the embryonic kidney (k), LacZ mRNA is mainly expressed in tubular cells (I, J, O), whereas Nolz-1 mRNA (K, L) and protein are detected broadly both in the metanephric mesenchyme (mm, O) and in ureteric tubules (ur, O). LacZ and Nolz-1 co-expressing cells in ureteric tub are detected (arrows, O). Double arrows in L and P indicate Nolz-1 expression in urogenital tube where LacZ and Nolz-1 co-expressing cells are found. g, gonads; li, liver; ad, adrenal gland.