A theoretical approach for the genetic code
The genetic code offers a wide field of interest for the physicist, as well as by the DNA structure as by the mechanism of polypeptide fixation from codons. We have proposed a few years ago a model based on continuous symmetries to consider some of these questions. Among other applications, sum rules for codon usage probabilities had then been obtained in this so-called Crystal Basis Model. More recently, imposing, still in the framework of our model, a minimum principle for the codon-anticodon interaction, the structure of the minimum set of anticodons allowing the translation-transcription for animal mitochondrial code has been obtained. Inequalities between codon usage probabilities for quartets of codons are also derived, in good agreement with the experimental situation. Such an approach is well adapted for an analysis of the evolution of the genetic code, as we will show in this seminar. This work is made in collaboration with A.Sciarrino, Università di Napoli, Italy.