RESTRICTION LANDMARK CDNA SCANNING (RLCS) - A NOVEL CDNA DISPLAY SYSTEM USING 2-DIMENSIONAL GEL-ELECTROPHORESIS

We have developed a new method, designated restriction landmark cDNA s canning (RLCS), which displays many cDNA species quantitatively and si multaneously as two-dimensional gel spots, In this method cDNA species of uniform length were prepared for each mRNA species using restricti on enzymes, After the restriction enzyme sites were radiolabaled as la ndmarks, the labeled fragments were subjected to high resolution two-d imensional gel electrophoresis. In analyses of cDNA samples from adult mouse liver and brain (cerebral cortex, cerebellum and brain stem) we detected -500 and >1000 discrete gel spots respectively of various in tensities at a time, The spot patterns of the three brain regions were very similar, although not identical, but were quite different from t he pattern for the liver, RNA blot hybridization analysis using severa l cloned spot DNAs as probes showed that differences in intensity of t he spots among RLCS profiles correlated well with expression levels of the corresponding mRNA species in the brain regions, Because the spot s and their intensities reflect distinct mRNA species and their expres sion level respectively, the RLCS is a novel cDNA display system which provides a great deal of information and should be useful for systema tic documentation of differentially expressed genes.