Transcription factor which may be involved in developmental processes such as cell fate determination, gene transcriptional regulation and progenitor cell regulation in a number of organs. May be essential in the development and function of the eye. May play a role in the regulation of the circadian rhythm by repressing the expression of clock genes. Additional isoforms seem to exist. Expressed most actively in the developing lens and midgut and at lower levels in the developing brain, heart, muscle and retina. First detected at stage 14 in the early lens placode. At later stages of development, it was observed throughout the lens, but it appeared more abundant around the bow region of the equator than in the anterior epithelium or the fibers. In the retina, expression was detected mainly in the inner nuclear layer during later stages of histogenesis. The Prospero-type homeodomain and the adjacent Prospero domain act as a single structural unit, the Homeo-Prospero domain. Belongs to the Prospero homeodomain family.