Mpp5a protein localization in zebrafish pronephric glomerulus. Immunoreactivity for Mpp5a protein is found in both medial and lateral half of nephron primordia at 34 hpf (arrowhead and small arrows in A). At 3 dpf, the signal for Mpp5a is found along the glomerular capillary wall as a tortuous line (arrowhead in B), in addition to the pronephric tubule (small arrows in B). Mpp5a signal is also found at the position of apical tight junction of neural tube (large arrows in A, B). In 3 dpf, immunoreactivity for ZO-1 (red) and Mpp5a (green) are colocalized within the glomerulus (arrowheads in C–C″). Mpp5a signal is also found at parietal epithelium of Bowman’s capsule (arrows in C–C″). In, intestine; NC, notochord. Scale bar = 10 µm.