Functions in the determination of disk-specific identity, downstream of Hox genes. Overexpression induces ectopic wings with antero-posterior and dorso-ventral axes in the eye field. Overexpression is sufficient for ectopic expression of vg in eye disks. Chromatin-associated; colocalizes on polytene chromosomes with Psc. Ubiquitously expressed throughout the larval and pupal developmental stages in larval tissues and imaginal disks. The BAH domain is required for localization to specific sites on polytene chromosomes. Truncated N-terminus.