Graphical Method to Determine Sequence Variation on NA Protein of H5N1 Virus using Discrete Wavelet Transform

Abstract

Influenza A virus belongs to the Orthomyxoviridae family and its genome is divided in eight distinct linear segments of negative-sense single stranded ribonucleic acid (RNA). Of all the eight influenza protein sequences, mutations in hemagglutinin and neuraminidase proteins show significant variations in their sequences. The threat of Influenza pandemic is ever rising due to its constant antigenic drift. Thus there is a need to characterize the genomic information in these viruses and signal processing methods offer the advantage of faster analysis in comparison to conventional techniques. Genomic information is converted into digital form by representation of the nucleotide bases in the form of mathematical sequences. In this paper, sequence variations of H5N1 virus have been studied using wavelet transforms as a signal analysis technique. Nucleotide sequences of neuraminidase protein of influenza virus occurring in different regions, in different hosts and over different years have been downloaded from National Centre for Biotechnology Information (NCBI) database. Sequences are aligned and converted into mathematical sequences then transformed using wavelet transforms. Graphical representations of the transformed sequences have been used to localise the regions of mutations along the sequence length.