ABD-A expression in <i>Abd-B</i> mutant embryos.

<p>Stage 14 embryos in A–C were stained with antibody to ABD-A, opened along the dorsal midline and flattened for photography. ABD-A is absent from PS13 in wild type (A), but appears throughout PS13 in <i>Df(3R)C4</i> homozygotes (B). In <i>Abd-B^D16</i> homozygotes, ABD-A is only in the lateral and dorsal epidermis of PS13 (C). Dissected CNS's from stage15 embryos in D were doubly stained for ABD-A (red) and ABD-B (green). In wild type, the expression domains overlap through PS10-12, with some nuclei expressing both proteins. In <i>Abd-B^D14</i> homozygotes, ABD-B expression is absent from PS10-13, but the ABD-A pattern is unchanged, leaving PS13 without either protein.