Study on the Influenza AVirus H5N1 Based on the Z-Curve Method

All over the world, many countries and regions have been made suffer a lot by the Avian Influenza. Especially Influenza A virus H5N1, which can cause illness in humans and many other animal species, has been a focus on many scientists. So it has become more and more important to research the evolution of the H5N1 and its features. There are many approaches to study the Influenza A virus H5N1. Among these methods the Z curve is a very useful method for visualizing and analyzing DNA sequences. It is a three-dimensional space curve constituting the unique representation of a given DNA sequence in the sense that each can be uniquely reconstructed from the other. This paper picks up the some DNA sequences of the Influenza A virus H5N1 (HA) from the NCBI database , which root in the same kind of host--chicken but occurred in different countries and different years, 2006,2007 and 2008, respectively. Based on the Z-Curve theory, we map the relevant curves and compare them, then calculate the base content. The conclusion is the corresponding Z curves of the sequences have some special geometrical features. It shows that the aberrance or evolution of Influenza A virus H5N1 (HA) relates with areas and years.