Fig. 2. Histology of the lumbar region of rs embryos at E11. (A,B,D,E) On the sections (A,D, near midsagittal; B,E, parasagittal; the rostral side is to the left of each panel), somite borders demarcated by intersegmental vessels (arrowheads in A,B,D,E) are clearly visible in the control (A,B), whereas they are unclear in rs/rs (D,E). DRGs (d in B,E) are fused in rs/rs (E), while they are clearly segmented in controls (B). (C,F) Transverse sections at a proximal tail region from control (C) and rs/rs (F) embryos reveal malformations of the neural tube in rs/rs. The epithelial organization of dermomyotome (dm in C) is disturbed in rs/rs (F). da, dorsal aorta; hg, hindgut; nc, notochord; nt, neural tube. Scale bars: 100 µm.