DEVELOPMENTAL REGULATION AND CELL-TYPE-SPECIFIC EXPRESSION OF THE MURINE GAMMA-F-CRYSTALLIN GENE IS MEDIATED THROUGH A LENS-SPECIFIC ELEMENT CONTAINING THE GAMMA-F-1 BINDING-SITE

The mouse gammaF-crystallin gene, one of six differentially regulated members of the gamma-crystallin gene family, is expressed exclusively in central nuclear fiber cells of the adult lens. The expression of th is gene is controlled through regulatory elements contained in two ups tream enhancers and the proximal promoter. Here we show that while the upstream enhancers and the proximal promoter could each direct gene e xpression in fiber cells formed at early stages of lens growth and dev elopment, cooperation between these elements is required to achieve ex pression in fiber cells formed at later stages. Evidence is provided t hat cooperative interaction between these elements modulates gene expr ession by increasing promoter strength. We also show that sequences wi thin the proximal promoter region that bind lens cell nuclear factor g ammaF-1 are sufficient to elicit gene expression in central nuclear fi ber cells of the adult lens. (C) 1993 Wiley-Liss, Inc.