The elements regulating lens-specific expression of the mouse gamma F-crystallin gene were examined. Here we show that mouse gamma F-crystallin sequences -67 to +45 contain a low basal level of lens-specific promoter activity and that sequences -67 to -25, which are highly conserved among different gamma-crystallin genes, are able to function as a strong transcriptional activator when duplicated and placed upstream of the TATA box. We also show that nuclear factors from lens and nonlens cells are able to form different complexes with sequences centered at -46 to -36 and demonstrate that binding of the factor from lens cells correlates with lens-specific promoter activity of the mouse gamma F-crystallin gene.