Regulatory sequences and nuclear factors governing tissue-restricted expression of the mouse arrestin gene were investigated. The results showed that while proximal promoter sequence positions -38 to +304 are sufficient to direct low levels of retina-specific gene expression, sequences extending upstream to position -209 support higher levels of expression in the retina, as well as detectable expression in the lens, pineal gland, and brain. Within the interval between positions -209 and -38, a broadly expressed nuclear factor, Bd, binds to sequences centered between positions -205 and -185, a region which contains two direct repeats of the hexamer, TGACCT. The proximal promoter binds three apparently retina-specific nuclear factors, Bpl, Bp2, and Bp3, through overlapping sequences centered between positions -25 and -15. Bpl and Bp3 also recognize a closely related sequence found in the promoter regions of several other vertebrate photoreceptor-specific genes. Moreover, the consensus binding site for Bpl, designated PCE I, is identical to RCS I, an element known to play a critical role in eliciting photoreceptor-specific gene expression in DrosophUia melanogaster. The results suggest that PCE I and RCS I are functionally as well as structurally similar and that, despite marked differences in the fly and vertebrate visual systems, the transcriptional machinery involved in photoreceptorspecific gene expression has been strongly evolutionarily conserved.