Research on the Evolutionary Tree for H1N1 Flu Virus Based on HA and NA Protein Sequences

Abstract:

The goal of this paper is to propose a new method for constructing evolutionary tree of H1N1 flu viruses in order to reveal the relationship between the molecular variation of H1N1 and epidemics. First，based on the 22455 HA and 16444 NA protein sequence data of H1N1 flu viruses from 1902 to 2013 years，the similarity index of protein sequences was constructed by using inner product of their eigenvectors. Then，the coarse-graining similar information of data was extracted by applying the complete graph clustering based on the similarity index of protein sequences. Finally，the evolutionary tree for HA and NA protein sequences of H1N1 flu viruses was studied by using the structure clustering method based on fuzzy proximity relations. Test results shown that the mutation of the H1N1 viruses was not only closely related to its outbreak time，but also to the outbreak regions and the geographical distances among the distribution regions，and the closer distance between the geographical distribution and the outbreak of the H1N1 viruses，the higher similarity degree of of the H1N1 viruses. Therefore，the new method based on the large data processing can effectively reveal the evolutionary relationship of H1N1 flu viruses，and can provide a foundation for further study of the mutation，evolution and prediction of flu viruses.