Fig. 2

Reduction of somitic mesoderm in no tail/spadetail double-mutants. Whole-mount in situ hybridizations. Anterior is towards the left, dorsal (A-J) and lateral views (E'-J'). (A-D) pax2a expression confirms the presence of intermediate mesoderm in ntl/spt; glomeruli are compacted in ntl/sp (arrowheads). (E-H,E'-H') Expression of aldh1a2 in somites is largely unchanged in ntl (F,F'), but reduced in spt (G,G') and absent in ntl/spt double-mutant embryos (H,H'); expression in double-mutants is upregulated in the ventral trunk (arrows), consistent with expression in intermediate mesoderm. (I-J') Double-staining reveals aldh1a2 expression in the intermediate mesoderm (delimited by arrowheads) of wild-type and ntl/spt embryos; the latter lack myod expression (J,J').