Comparative Analysis Of Bacterial Essentiail And Non-essential Genes Based On Chaos Game Representation

With the development of molecular biology techniques, DNA sequencing work has been widely carried out. Research of DNA sequence structure and how it determines the transmission and express of genetic information, has important practical significance. Therefore, DNA sequence analysis has become an important basis for genetic research. Essential genes are necessary to maintain basic life activities of genes, identify the essential gene sequences has the important application value for the new drug development and disease control. Due to the huge amount of data of species, there are many species essential genes has not yet been determined, and the actual process is very cumbersome. So comparative analysis of essential and non-essential genes by the nonlinear theory is very necessary for identification of two kinds of genes.In this paper, comparative analysis of the Hurst exponent and the information dimension of bacterial essential and non-essential genes is studied based on chaos game representation method. We found that Hurst exponents of both essential and non-essential genes follow Gamma distribution, there is a linear relationship between the sequence length and Hurst exponent.Moreover, there exists significant difference between the Hurst exponents of essential and non-essential genes. For the protein sequence information dimension, there is a linear relationship between the protein sequence length and the information dimension. The information dimension of most bacterial essential and non-essential genes has a significant difference. In addition, similarity comparison of cytochrome C sequences of 21 organisms is made by using absolute difference method and Pearson distance method. The result shows that the evolutionary tree drawn with Pearson distance method is more in line with biological evolution relationship than absolute difference method.