Transcription regulator. Does not seem to be essential for embryonic development and postnatal survival. Expressed in testis. Expressed in the developing nervous system. Expressed at 9.5 dpc in the geniculate (VIIth), petrosal (IXth), and nodose (Xth) ganglia. Expressed in postnatal eyes. The Prospero-type homeodomain and the adjacent Prospero domain act as a single structural unit, the Homeo-Prospero domain. Mice grow normally and body weight was similar to that of wild type. Heterozygous mutant mice survived to adulthood and appeared normal. Belongs to the Prospero homeodomain family.