Expression of type IV collagen α3 chain in the Danio rerio. Adult Danio rerio tissues were stained with anti-human α3(IV) antibodies and H&E. (A-B) In Danio rerio the gills are the equivalent of the lung. Strong expression of α3(IV) can be seen in the Danio rerio gills (green). DAPI staining is used to stain the nuclei of cells (blue). (C-D) In Danio rerio the kidney is the main hematopoietic organ and thus morphologically distinct from that of higher organisms (C). Strong expression of α3(IV) can be seen in both the GBM (G) and the tubular basement membranes (T) as well as in the hematopoietic tissue (HP) (D).