Figure 7. Perturbations of the Müllerian duct (MD) and rete ovarii by deletion of Pax2 and/or Pax8 disrupt ovary morphogenesis.

(A) Pax2/Pax8 deletion allelic series. Maximum intensity projections from confocal Z-stacks of whole ovary/mesonephros complexes at E17.5 and E18.5, immunostained for KRT8 (cyan) and PAX8 (red). Each sample is representative of the phenotype observed for different combinations of Pax2 and Pax8 deletion alleles. Images in the top row were captured from the dorsal side, and images in the middle, and bottom row from the dorsal side. Images in the bottom row are close-ups of the regions outlined in the middle row. White arrows point to disruptions of the MD. Dashed lines in the bottom row represent the KRT8+ cortical domain of the ovary. (B) The segment of the oviduct is required for ovary encapsulation. Maximum intensity projections from confocal Z-stacks of whole ovary/mesonephros complexes at E17.5, immunostained for KRT8 (cyan) and counterstained with Hoechst nuclear dye (grayscale). The dashed outline represents the ovarian capsule, which is absent in Pax2^del/del; Pax8^del/+ samples. (C) Only the infundibulum and connecting rete persist in Pax2^del/del; Pax8^del/+ samples. Maximum intensity projections from confocal Z-stacks of whole ovary/mesonephros complexes at E17.5, immunostained for KRT8 (cyan) and PAX8 (red). Images in the bottom row are close-ups of the regions outlined in the top row: left, rete ovarii; right, infundibulum. (D) The cranial suspensory ligament (CSL) remains tethered to the infundibulum remnant in Pax2^del/del; Pax8^del/+ and Pax2^del/+; Pax8^del/del samples. Maximum intensity projections from confocal Z-stacks of whole ovary/mesonephros complexes at E18.5, immunostained for KRT8 (cyan), aSMA (green), and TNC (red). Images in the bottom row are close-ups of the regions outlined in the top row. White arrowheads point to the attachment of the CSL to the infundibulum. Yellow asterisks indicate the location of the infundibulum of the presumptive oviduct for reference. CR, connecting rete; EOR, extraovarian rete; IOR, intraovarian rete; Mv, mesovarium; OA, ovarian artery; OC, ovarian capsule; Ov, ovary; Ovi, oviduct, Ut, uterus. Scale bars, 100 μm.

Figure 7—figure supplement 1. Gross morphology of Pax2^del; Pax8^del fetuses.

(A, B) Macrophotography of the urogenital complex in situ (top row) or isolated (bottom row) in Pax2^del/+; Pax8^del/+ (A) or Pax2^del/del; Pax8^del/+ (B) fetuses at E18.5. (C) Macrophotography of the isolated urogenital complex from a Pax2^del/+; Pax8^del/del fetus at E18.5. Note the absence of kidneys (K) in (B) and (C), and the resulting shorter distance between ovary (ova) and adrenal (A) compared to (A). A, adrenal; B, bladder; DA, dorsal aorta; K, kidney; MD, Müllerian duct; Ova, ovary; Ovi, oviduct.