ABSTRACT
It was in the year 2000 that qualitative graphical bioinformatics saw dramatic change-change to a quantitative discipline. One of the present authors (MR) was attending a seminar at the Natural Resources Research Institute of the University of Minnesota in Duluth by a visiting scientist from India, Dr. Ashesh Nandy. He was presenting his two-dimensional graphical representation of DNA. Nandy was showing and comparing visually graphical representations of various DNA. In Figure 13.1, we show a segment of DNA constructed by moving along the DNA sequence following the rule: For each A, move one step along –x-axis; for each C, move one step along +y-axis; for each G, move one step along +x-axis; for each T, move one step along −y-axis. So constructed 2-D graphical representations allowed Nandy to arrive at some insights into similarities of various DNA. Looking at these 2-D graphical representations of DNA, it was immediately clear to MR that such graphical representations of DNA can be numerically characterized by D/D matrices, just as one can numerically characterize molecular structures having fixed geometry. Over the following days in Duluth, a manuscript on numerical characterization of graphical representations of DNA was prepared [4].
