Abstract
Abstract: :
Purpose. The mouse αA-crystallin (αA) promoter is effective at driving transgene expression to lens fiber cells, but not to lens epithelium. A modified lens-specific promoter was made in an attempt to achieve transgene expression in both lens epithelium and fiber cells. Methods. Chick δ1-crystallin lens enhancer was added to the 5’-end of αA promoter to create δen-αA. To test the δen-αA promoter activity in transgenic mice, several minigenes were constructed using different types of introns and polyadenylation signals. Transgene expression was analyzed by X-gal staining, immunohistochemistry, or in situ hybridization. Results. Staining the whole embryo with X-gal showed that, at embryonic day 11.5 (E11.5), eye is the only place where lacZ reporter gene is expressed. Eye sections of the stained embryo showed expression in both lens epithelial and fiber cells. Transgenic mice expressing insulin were generated using either αA or δen-αA promoter. In situ hybridization confirmed that αA targets insulin expression only in lens fiber cells, while δen-αA targets expression in both lens epithelial and fiber cells. Developmental studies showed that δen-αA is activated in the lens at E10.5 and high activities remain in all lens cells throughout development. δen-αA also successfully drives transgene T-antigen, E2F2 and P57/Kip2 expression in both lens epithelium and fiber cells, confirming consistency of the δen-αA promoter. Conclusions. δen-αA is a lens-specific promoter, driving high levels of transgene expression in both epithelium and fiber cells throughout development. δen-αA is particularly useful for transgenic studies requiring protein expression in lens cells before fiber differentiation occurs.
Keywords: transgenics/knock-outs • gene/expression • molecular biology