<p>The Dorsal morphogen directs formation of the Drosophila dorsoventral axis by both activating and repressing transcription. It contains an N-terminal Rel homology domain (RHD), which is responsible for DNA binding and regulated nuclear import, and a C-terminal domain (CTD) that contains activation and repression motifs [<cite idref="PUB00014581"/>].</p> <p>In wild-type embryos, the dorsal protein is found in the cytoplasm during cleavage. After the nuclei migrate to the periphery of the embryo, a ventral-to-dorsal gradient of nuclear dorsal protein is established [<cite idref="PUB00014582"/>].</p> Dorsal protein