Transcription factor which is a downstream target of gcm and repo. Directly or indirectly activates the transcription of locos and pros, which are essential for the development of some glial cells. Plays an essential role in defining the cell shape and migration characteristics of longitudinal glia that enable them to establish a normal axon scaffold. Present in the pharyngeal muscles, hindgut epithelium, amnioserosa, ring gland, midgut-hindgut junction, posterior region of each brain lobe, longitudinal glial cells of the CNS and the salivary gland duct of germ-band retracted embryos. Expressed maternally throughout the embryo at the syncytial cleavage divisions and zygotically at the termini and in a broad central band during cellularization. At germ band extension, the protein is found in the mesoderm. Expressed in a subset of neurons from larva and pupa. Flies show axon guidance abnormalities in mushroom bodies and pathfinding errors by photoreceptor and subesophageal neurons. Female flies with retn defects are strikingly resistant to male courtship and show male-like courtship of females and males, especially as they age.