CATALOGING ALTERED GENE-EXPRESSION IN YOUNG AND SENESCENT CELLS USINGENHANCED DIFFERENTIAL DISPLAY

Recently, a novel PCR-based technique, differential display (DD), has facilitated the study of differentially expressed genes at the mRNA le vel, We report here an improved version of DD, which we call Enhanced Differential Display (EDD), We have modified the technique to enhance reproducibility and to facilitate sequencing and cloning, Using EDD, w e have generated and verified a catalog of genes that are differential ly expressed between young and senescent human diploid fibroblasts (HD F), From 168 genetags that were identified initially, 84 could be sequ enced directly from PCR amplified bands, These sequences represent 27 known genes and 37 novel genes, By Northern blot analysis we have conf irmed the differential expression of a total of 23 genes (12 known, 11 novel), while 19 (seven known, 12 novel) did not show differential ex pression. Several of the known genes were previously observed by other s to be differentially expressed between young and senescent fibroblas ts, thereby validating the technique.