Wild-type mouse diaphragms at E13.5 (A) and E14.5 (B). In three consecutive frames of 240 × 240 μm in the vicinity of the nerve entry, stacks of images were taken at 0.5 μm intervals, and maximum intensity projections (left) and three-dimensional renderings (right, in full and semitransparent coloring) were made to resolve neuromuscular contacts (yellow). At E13.5 (A), microclusters increased in number and many are enlarged compared with E12.5. Only a small minority of clusters in the central AChR cluster band are contacted by nerve (large arrow). Note that some branches grow laterally beyond the AChR cluster band (small arrows). At E14.5 (B), the band of AChR patches is significantly wider and AChR patches are significantly larger than at E13.5. Numerous clusters are contacted by axons (yellow). Scale bar, 30 μm.