A Study On The Distribution Of Bases In Human DNA Sequences

DNA is heredity substance for storing gene information. Genes, simply speaking, are hereditary basic function unit. The up-to-date implication of gene is the integrated DNA section of coding a RNA molecule or protein molecule. In chemistry, gene is nucleotide's linear array, that is DNA sequences' section. Heredity information array in genes is the four bases A, C, G, T array. When the four bases order is definite, the amino acid order of one-to-one correspondence protein is definite, and genes determined ultimately the feature of organisms.With the increasing rapidly of the number of known DNA sequences, the study and analysis of base distribution become more and more important in molecular biology. In this paper, we study and analysis the base distribution in human DNA sequences. On the basis of the distribution sphere whose radius equal to 1/4 by Zhang et al. expounded, with the method of plane mapping figure studying 6000 human DNA sequences, and according to the figure of sierpinski gasket's patch and The brillouin zones of the face-centered cube, we obtain two new distribution figures, one is the frustum-octahedron, another is the regular-octahedron. Through the study and analysis conclude as follows: in human DNA sequences, if the distinction of the number of the four bases is very small, they can distribute in a sphere whose radius equal to 1/4; if the distinction of them is comparative large, they can distribute between the sphere and the frustum-octahedron; if one is 0 in them, they can distribute between the frustum-octahedron and regular-octahedron; if the distinction of them is especial large, they may distribute in the outer of the regular-octahedron.These conclusions are expounded on the basis of the peculiarity of cube and regular tetrahedron of DNA sequences, so they are rationalization, and they will be very useful in the study of the classification and the evolution of organisms.