QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 5 January 2005
doi: 10.1242/dev.01604

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Development Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Levinson, R. S. Articles by Mendelsohn, C. L. Search for Related Content PubMed PubMed Citation Articles by Levinson, R. S. Articles by Mendelsohn, C. L.

Foxd1-dependent signals control cellularity in the renal capsule, a structure required for normal renal development

¹ Department of Urology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
² Department of Pathology, and College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
³ Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA

View larger version (109K): [in a new window]   Fig. 1. Histology of paraffin wax-embedded sections of wild-type and Foxd1-null kidneys. At E11.5 (A,B), ureters in Foxd1+/+ (A) and Foxd1lacZ/lacZ (B) embryos extend dorsally into the kidney blastemas. At E12.5, wild-type kidneys (C) have rotated and separated (only the right kidney is pictured). A gap (yellow arrowheads) separating the kidney from the body wall occurs. In the Foxd1 null (D), the kidneys have failed to separate and are surrounded by a thick layer of mesenchyme (yellow arrowheads). At E14.5, the wild-type (E) is almost fully detached (yellow arrowheads), while the Foxd1-null kidneys (F) continue to remain attached to the dorsal body wall (yellow arrowheads). da, dorsal aorta; ub, ureteric bud; cm, condensed mesenchyme. Scale bar: 75 µm for A,B; 150 µm for C,D; 200 µm for E,F.

View larger version (96K): [in a new window]   Fig. 2. Expression of Foxd1lacZ in heterozygous and mutant embryos. At E13.5 (A,B) there is strong Foxd1lacZ expression in the dorsal body wall and kidneys, as well as a trail of ß-gal+ cells that leads into the capsule of the kidney (arrowheads). At E16.5 (C,D), this trail is thinner (left arrowheads) and a gap between the normal kidney and the dorsal body wall exists (C, right arrowheads), while the mutant kidney is still attached (D, right arrowhead). In wild type (C'), there are both round ß-gal+ cells in the loose connective tissue between the kidney and the dorsal body wall (yellow arrowheads) and flattened ß-gal+ cells in the renal capsule (red arrowheads). In the mutant (D'), there is a mixture of ß-gal+ and ß-gal- cells in the capsule (red arrowheads). At E18.5, the wild-type capsule (E) still consists of a single layer of ß-gal+ cells (red arrowheads), which persists into early adulthood (G). At E18.5, the mutant capsule is thickened (F,F') and still contains a mixture of ß-gal+ (blue arrowheads) and ß-gal- cells (red arrowheads). Higher magnification of bracketed areas in C, D, and F are displayed in (C',D',F'). d, dorsal; v, ventral; cs, cortical stroma. Scale bar: 400 µm for C,D; 250 µm for A,B; 120 µm for C',D'; 75 µm for E,F; 20 µm for G,F'.

View larger version (63K): [in a new window]   Fig. 3. Genetic markers reveal that the renal capsule in the Foxd1 null is aberrant. Arrowheads indicate the position of the capsule. ß-Gal+ cells populate the capsule of the heterozygote (A) and mutant (B). Raldh2 expression in the heterozygote (C) is at high levels in the capsule and the cortical stroma (cs) and is at lower levels in the mesenchyme of the nephrogenic zone. In the mutant (D), Raldh2 is undetectable in the capsule, though a low level of expression remains in the mesenchyme. Sfrp1 expression in wild-type (E) is at high levels in the capsule, but almost undetectable in the mutant (F). Normally (G), Pecam1 expression (brown cells) is localized to the interior of the kidney, away from the capsular stroma (blue cells), but is in high abundance in the capsule of the Foxd1 null (H). Reactivity with peanut agglutinin (PNA) normally is not detectable in the capsule (I), but there is ectopic reactivity in the Foxd1 null at this age (J). Scale bar: 100 µm for A-D; 150 µm for E-H; 200 µm for I,J.

View larger version (115K): [in a new window]   Fig. 4. Ectopic localization of Bmp4+ cells and signaling in the kidney of the Foxd1 null. At E14.5, Bmp4lacZ expression is normally limited to the ureter and structures in the interior of the kidney (A). A Foxd1-null mutant (B) displays weak expression in the interior of the kidney, but high expression in the capsule (ca). At E12.5 (C,D), Bmp4lacZ expression is present in the midline of both Foxd1-null and heterozygous tissue but there is a wider distribution of expression around the kidneys in the mutant. We confirmed these results at E12.5 by immunofluorescence with an anti-ß-gal antibody (red cells in E,F) and GFP expression from the Foxd1GFP allele (green cells in E,F). Expression of GFP and lacZ did not overlap. At E18.5, the heterozygous and mutant kidney both displayed similar expression of Bmp4lacZ (G,H). At E12.5, phospho-Smad1 expression (brown) is in the pre-tubular aggregates (pa) (I,I'), while weaker expression is displayed in the condensed mesenchyme on both sides of the UB. There is no expression in the nascent capsule layer (nca). In the Foxd1-null (J,J'), phospho-Smad1 expression is strongly expressed in the pre-tubular aggregates, but there is also expression in the nascent capsule layer. At E14.5 in wild type (K,K'), phospho-Smad1 expression is in the pre-tubular aggregates, the renal vesicles (rv) and the UB stalk, but not in the condensed mesenchyme above the UB tips, nor the part of the UB tips that face the capsule (ca). In the Foxd1 null (L,L') phospho-Smad1 expression is also in pre-tubular aggregates and renal vesicles, but these structures are ectopically positioned between the UB and the capsule. Higher magnification of the bracketed areas in I-L are displayed (I',J',K',L'). Scale bar: 200 µm for A,B,G,H,K,L; 100 µm for C-F,I,J; 75 µm for K',L'; 50 µm for I',J'.

View larger version (108K): [in a new window]   Fig. 5. Nephrogenesis is delayed and disorganized in the Foxd1 null. (A) Wild type displayed Pax2 expression in condensed mesenchyme (cm) around the UB tips. The Foxd1 null (B) displayed much larger condensates. Wild type (C) and Foxd1 null (D) displayed Wnt4 expression in pre-tubular aggregates (pa) and both displayed expression of Sfrp2 in renal vesicles (rv) (E,F). Cell proliferation was determined by Ki-67 reactivity (G,H). Histochemistry with TRITC-PNA and FITC-lotus lectin revealed the presence of glomeruli (red spheres) and proximal tubules (green structures), respectively. At E15.5 and E16.5, wild-type kidneys (I,K) displayed glomeruli (gl) and proximal tubules (pt) in the juxtamedullary region, just below the nephrogenic zone. The Foxd1 null displayed no glomeruli or tubules at E15.5 (J), but did so at E16.5 (L), although there is no discrete nephrogenic zone. At E18.5, both the wild-type kidneys (M) and the Foxd1-null (N) display numerous glomeruli and proximal tubules, but they are poorly organized in the mutant. We counted 100 nephrons in M and 85 nephrons in N. Scale bar: 250 µm in A,B,D-F,I,J; 150 µm in G,H,K,L; 300 µm in M,N.

View larger version (97K): [in a new window]   Fig. 6. Maturation of the ureteric tree in the Foxd1 null is defective. At E18.5 in HoxB7GFP/+;Foxd1+/+ kidneys, branches of the ureteric bud (ub) have bifurcated numerous times (A). In HoxB7GFP/+;Foxd1lacZ/lacZ (B) the branches elongate but bifurcate very infrequently. Ret expression at E14.5 in wild-type whole-mount tissue (C) is limited to the tips, but has a wider distribution in the mutant (D). This result was confirmed in thin sections (E,F). Higher magnification of the bracketed regions in E and F reveals that wild-type (E') displays strong diminishment of expression in the cleft (arrowhead) of the UB, where there is no condensed mesenchyme, but the Foxd1-null (F') displays strong expression throughout this region of the UB. However, there is no detectable Ret expression in the region of the UB that is not in contact with the condensed mesenchyme (arrowheads). cm, condensed mesenchyme. Scale bar: 75 µm in A-D; 50 µm in E,F; 25 µm in E',F'.