Figure 4.

Identification and expression of a nematode Dll gene. (a) Alignment of the homeodomains of Drosophila (52), mouse (48, 53), and nematode Dll/Dlx (50) gene products. The amino acid sequence of the Ce-Dll homeodomain is 74% identical to that of Drosophila Dll. (➤), The position of an intron conserved between the fly (54), ascidian (15), and nematode (50) genes. (b and c) Lateral views of 100-cell (b) and comma (c) stage Caenorhabditis elegans embryos stained with the Dll antibody (green) and an antibody (O1C1D4) that recognizes P-granules (blue). (d) Dorsolateral view of a three-fold stage C. elegans embryo stained with the Dll antibody (green) and an antibody (3NB12) that recognizes pharyngeal cells (red). The Ce-Dll expressing cells in b and c are the precursors of the nerve ring cells that express Ce-Dll in d. Anterior is to the left in b–d, and the magnification in b–d is the same. (Bar = 10 μm.)