ABSTRACT
Hepatitis B is a serious infectious disease worldwide, and hepatitis B virus (HBV) is the direct cause of this disease. In recent years, as an essential part of its evolutionary process, HBV mutation has been extensively studied domestically and globally. However, the study on the conserved sequences in HBV sequences is still in its infancy. In this study, we applied multiple EM for motif elicitation (MEME) algorithm to discover HBV motif and proposed a new metric, conservative index (CI), to carry out phylogenetic analysis based on HBV sequences. Then, the constructed phylogenetic tree was subjected to reliability assessment. The results demonstrated that the new metric CI combined with the MEME algorithm can effectively help to discover motifs in HBV sequences and construct a phylogenetic tree based on them and to analyze the evolutionary relationship between HBV sequences; in addition, the possible ancestral sequences of samples may be obtained by conservative analysis. The proposed method is valuable for the exploratory study on large HBV sequence data sets.
Subject(s)
Humans , Computational Biology , Conserved Sequence , Evolution, Molecular , Hepatitis B virus , Genetics , Nucleotide Motifs , Phylogeny , Reproducibility of ResultsABSTRACT
Hepatitis B is one of the most serious global threats to human health. Phylogenetic analysis of hepatitis B virus (HBV) can reveal the evolutionary relationship between HBV sequences and thus provide a basis for the prediction and treatment of hepatitis B and other aspects. In this study, we performed sequence analyses on the HBV sequences of five clinical HBV samples and the HBV sequences retrieved from the GenBank, EMBL, and DDBJ to construct a phylogenetic tree and analyze sequence structures. The experimental results revealed that the C gene of one cloned sequence had a recombinant structure of HBV B/ C subtype. Moreover, the phylogenetic results proved the existence of a newly found subtype HBV/B6 in Xishuangbanna of Yunnan Province, China. The experimental conclusion represents certain value for phylogenetic studies of HBV in Yunnan ethnic minority groups.