ABSTRACT
This chapter focuses on the basic transcription of a single gene in the context of chromatin. Complimentary DNA (cDNA) is frequently used in biochemical assays; it corresponds to DNA of a proper gene, and can be obtained from retranscribed mRNA products after splicing has occurred. The chapter addresses how DNA is repaired in the chromatin context and how the genome is duplicated by the process of replication. While the physical mechanism of DNA denaturation is already indicative of the involvement of physical effects also in splicing, recent functional genomics results point to yet another picture, related to the presence of nucleosomes. The chapter describes a basic idea about exons and introns by looking at genomic DNA and at cDNA. GC content can be shown to be significantly enhanced near the center of constitutive exons. The fact that exons exist gives room for a large variation: proteins that are translated can originate from different exon elements.
