We propose to build a database of quantitative information concerning the expression of the 10,000 to 20,000 most prevalent mouse brain mRNAs in different anatomical sites within the brain, at several developmental stages, in peripheral tissues, and in response to physiological and behavioral paradigms. From the data, to be collected by a newly developed PCR-based methodology conceptually similar to but more exhaustive than differential display, we will recognize a few thousand differentially expressed or physiologically regulated mRNAs. We will determine partial sequences of 900 differentially expressed or regulated mRNAs, which will provide an identity tag for each and lead to the identification of novel proteins. Specific PCR primers will be used to establish expression profiles at higher degrees of precision and for SSCP-PCR amplification of genomic DNA from a panel of 94 interspecific backcross mice so as to determine linkage of each PCR product, within a few cM, to markers already mapped on the panel. From these studies will emerge an annotated public database cataloguing PCR primer, PCR product length, relative amounts of the products in different tissues, partial nucleotide sequence and gene location in which genes identified by their differential expression patterns can be identified by scientists with particular developmental/physiological/ behavioral questions for in depth studies. Equally important, the genetic and expression pattern aspects will allow candidate genes for genetically determined disorders of the CNS and certain peripheral tissues to be recognized. The studies will answer questions of gene number and clustering of genes preferentially transcribed in specific anatomical and/or developmental windows, and provide a better understanding of patterns of gene expression, and thus will provide baseline data for a technology that is certain to become, because of its digital approach to total gene expression, a major analytic tool for discerning normal and defective physiological function.
