Normal neural patterning and motor neuron development in Dicer mutant spinal cord. Spinal cord sections from E11.5 Olig1Cre/+/Dicer+/+ and Olig1Cre/+/Dicerflox/flox embryos were immunostained simultaneously with anti-Olig2 and anti-Pax6 (A, B), anti-Nkx2.2 (C, D), anti-HB9 (E,F) or anti-Isl-1(G,H). I. Quantification of HB9+ and Islet1+ motor neurons in the control and Dicer mutant tissues (n=3).