18 RNA Gene Analysis
Abstract
This chapter describes basic techniques to characterize the primary structure of RNA gene products and the proteins that associate with these RNA to form ribonucleoprotein particles. In yeast, the identification of protein coding genes is relatively straightforward. In its most unsophisticated form, it relies on the identification of open reading frames (ORFs) longer than a statistically defined threshold refined with the search of features, such as putative splice sites. Recently, protein coding gene determination was made considerably more accurate by comparative genomic studies in which protein sequence conservations allowed a reliable annotation of the genome for protein coding gene. The most widely used technique so far to characterize transcripts is Northern-blot hybridization. New technologies, such as those based on DNA microarrays, are now available and are powerful tools for genome-wide transcript analysis, but aside from the new tiling-array technology that is emerging or specialized arrays, it is essentially useful for relative quantifications but will not be able to detect any structural variations or heterogeneities.