Essential protein that may function as a transcription regulator. Vital for pupal development. Required for proper development of the optic lobes and wings, and abdominal pigmentation. In third-instar larvae, expressed in the brain region that will develop into optic lobes and more weakly in the thoracic part of the ventral ganglion. The peak periods of expression are: mid-embryogenesis, the second day of pupal development and in the adult.