A HIGHLY CONSERVED LENS TRANSCRIPTIONAL CONTROL ELEMENT FROM THE PAX-6 GENE

We have identified a short segment of the mouse Pax-6 gene 5' flanking region that is necessary and sufficient for reporter construct expres sion in components of the eye derived from non-neural ectoderm. This t ranscriptional control element has a highly conserved nucleotide seque nce over 341 bp and is located approximately 3.5 kb upstream of the st art-point for transcription from the most proximal promoter (PO) of th e Pax-6 gene. The level of identity between the human and mouse Pax-6 genes in this region is 93%. When combined either with its natural pro moter or a heterologous minimal promoter, this element directs reporte r construct expression to a region of surface ectoderm overlying the o ptic cup beginning at E8.5-9.0 (12-14 somites). Subsequently, expressi on is restricted to the lens (primarily the lens epithelium) and the c orneal epithelium. This element will provide an important tool in futu re transgenic analyses of lens formation and will allow identification of transcription factors with a central function in lens development. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.