The literature on recoding is scattered, so this superb book ?lls a need by prov- ing up-to-date, comprehensive, authoritative reviews of the many kinds of recoding phenomena. Between 1961 and 1966 my colleagues and I deciphered the genetic code in Escherichia coli and showed that the genetic code is the same in E. coli, Xenopus laevis, and guinea pig tissues. These results showed that the code has been c- served during evolution and strongly suggested that the code appeared very early during biological evolution, that all forms of life on earth descended from a c- mon ancestor, and thus that all forms of life on this planet are related to one another. The problem of biological time was solved by encoding information in DNA and retrieving the information for each new generation, for it is easier to make a new organism than it is to repair an aging, malfunctioning one. Subsequently, small modi?cations of the standard genetic code were found in certain organisms and in mitochondria. Mitochondrial DNA only encodes about 10–13 proteins, so some modi?cations of the genetic code are tolerated that pr- ably would be lethal if applied to the thousands of kinds of proteins encoded by genomic DNA.
The dynamic nature of decoding the information in messenger RNA was unanticipated at the time the genetic code was first deciphered. We now know that both the meaning of individual codons and the framing of the readout process can be modified by information in specific messenger RNAs. This book describes this "Recoding" phenomenon, revealing the diversity of an additional layer of information in mRNAs that serves to enrich the expression of genes. Knowledge of recoding is essential for understanding the organization and expression of genes in viruses and all organisms ranging from bacteria to archeae to plants to humans, making Recoding pertinent to all biological sciences.