Fig. 1. Expression of Hoxd10 in normal chick embryos from stage 15 to stage 25. In situ hybridization on (A,C,E) whole mounts, or (B,D,F) transverse sections. Asterisks in A, C and E mark the approximate levels of the transverse sections. (A,B) Dorsal and transverse views of posterior neural tube regions at stage 16 (A) and stage 15 (B). At stages 15-16, Hoxd10 is diffusely expressed in the tail bud, the neural tube through midLS levels, and LS lateral plate mesoderm (arrow in B). The neural tube at future anterior LS levels shows little if any Hoxd10 expression (arrow in A). (C,D) Ventral and transverse views at stage 21. A ventral laminectomy and hemisection were performed on the embryo pictured in C, revealing one half of the ventral surface of the spinal cord. High expression is visible in the stage 21 ventral LS neural tube, in the region of the future motor columns. Diffuse Hoxd10 expression is still visible at the posterior end of the embryo (arrow in C). (E,F) Ventral and transverse views at stage 25. In the embryo pictured in E, a ventral laminectomy was performed prior to processing. Hoxd10 expression is widespread in postmitotic neurons in LS segments, but not in adjacent segments. Cells lining LS ventral roots (arrow, F) also show expression. Bars, 250 µm.
