Isolated ureteric buds from E11.5 Dicer mutants (b) and control littermates (a) showed no significant difference at the point of dissection. On culturing in Matrigel supplemented with Gdnf and retinoic acid, the mutant ureteric buds (d, f, h, j, l) displayed a significant reduction in branching compared to ureteric buds derived from kidneys of control littermates (c, e, g, i, k) as early as 24 h in the culture (d). Scale bar =10 μm.