Fig. 7. Mid-dorsal and ventral populations of neurons are not affected in Bmpr double knockout animals. (A,B) Lmx1b expression labels the DI5 neurons of the dorsal spinal cord at 11.5 dpc normal (A) and mutant animals (B). (C) In normal animals, Lim1/2 is expressed by three populations of dorsal sensory neurons, DI2, DI4 and DI6, and by two populations of ventral neurons, V0 and V1. (D) In double mutant animals, Lim1/2 expression is unaffected in the DI6, V0 and V1 populations, but the number of DI2 cells is greatly reduced (arrow). (E,F) Sections from 11.5 dpc spinal cord, labeled with antibodies against Isl1/2 (green) and Pax2 (red). (E) In the neural tube, Isl1/2 marks dorsal DI3 cells and ventral motoneurons (MN). Pax2-positive cell groups include DI4, DI6, V0 and V1. (F) In double knockout animals, DI3 and DI4 cells are shifted dorsally toward the roof plate (^*), but are otherwise normal. Other populations marked by Isl1 and Pax2 are unaffected. (G,H) Sections from 11.5 dpc spinal cord, showing expression of En1 in normal (G) and double knockout (H) animals, indicating V1 populations are unaffected.