Fig. 8. Loss of IRSp53 causes defects in pro-nephric ducts and in adult kidneys in zebrafish.

a Digital light sheet confocal images of 72 hpf pronephric ducts. Embryos obtained from either wild-type (b2a WT) or baiap2a (b2a −/−) mutant females in a Tg(CldnB:GFP) genetic background were treated with scrambled morpholino (b2a WT; b2a −/−) or with spliced and translation blocking morpholinos (b2a WT b2b_Mo; b2a −/− b2b_Mo), and fixed and mounted in agarose. Samples were stained with an anti-GFP antibody (green) and DAPI (blue). Z-stack projections (magnification, 3.4×) are shown on the right for the dashed, rectangular boxes on the left. Arrowhead, extra-duct structure in the b2a −/− b2b_Mo embryo. Scale bars, 10 µm. Two-thirds of the b2a −/− b2b_Mo embryos showed such defects (n = 8/12). b) Hematoxylin and eosin staining of adult zebrafish kidneys. Adult wild-type (b2a WT) and b2a −/− strains were fixed, decalcified, and paraffin embedded. Bottom: Magnification (2×) of the light green dashed boxes from the upper images. Renal tubules are surrounded by yellow dashed lines. Arrowheads, abnormal disarrayed and not patent tubules in the b2a −/− sample, characterized by the irregular distribution and shape of the nuclei; asterisks, vascular lacunae; arrows, infiltrating cells. In all, 70% of the b2a −/− samples show such defects (n = 7/10) versus ~10% of the b2a wild-type (n = 1/9). Scale bar, 50 µm.