Lens-specific expression of a chicken beta A3/A1-crystallin promoter fragment in transgenic mice.

Beta A3/A1-crystallin is one of the major refractive proteins of the chicken eye lens. Previously we showed that a fragment from -382 to +22 bp of the beta A3/A1-crystallin gene functions as a promoter in transfected lens cells. Here we show by use of the bacterial chloramphenicol acetyltransferase reporter gene that the -143/+22 fragment is sufficient for lens-specific promoter activity in transgenic mice. DNase I footprinting shows that lens nuclear proteins protect several regions within the minimal promoter fragment.