Seminario "Statistical Mechanics of long-⁠range correlations in DNA sequences", Prof. M. Caselle (Torino)

Abstract. One of the most surprising features of higher eukaryotes genomes is the presence of long range correlations in the composition of the DNA sequence. These correlations were discovered more than 20 years ago when the first long continuous DNA sequences became available. In the past few years, thanks to next generation sequencing, an impressive amount of whole-⁠genome sequences have been published, and the composition of genomic DNA can be now studied systematically over a wide range of scales and organisms. This makes now possible to assess the various models proposed for their description. In Statistical Mechanics long  range correlations are the distinctive features of critical points, however it is well known that no such point may exist in one dimensional models with local interactions. In this talk we discuss an alternative possibility, involving non local interactions. We model DNA correlations in the human genome using the long range one dimensional Ising model. For distances between $10^3$ and $10^6$ bp the correlations show a universal behavior and may be described by the non-⁠mean field limit of the model. This allows us to make some testable hypothesis on the evolutionary mechanisms and on the nature of the interactions between distant portions of the DNA chain which led to the formation of the DNA correlations that we observe today in higher eukaryotes.

Persona di contatto:S. Stramaglia   This email address is being protected from spambots. You need JavaScript enabled to view it.

Relatore:Prof. Michele Caselle (U. di Torino e INFN, Torino)