title: Recombination and natural selection in hepatitis E virus genotypes.
abstract: To gain new insights into the evolutionary processes that created the genetic diversity of the hepatitis E virus (HEV), the Recombination Detection Program (RDP) and SimPlot program were employed to detect recombination events in the genome, then the fixed-effects likelihood (FEL) method was used to detect natural selection effects on viral proteins. Recombination analysis provided strong evidence for both intergenotype and intragenotype recombination events in the sequences analyzed. Recombination events were found to be distributed non-randomly, with the highest frequency in the X domain and the helicase. Strain DQ450072 was identified as intergenotype-recombinant. Natural selection analysis revealed that codons under both negative selection and positive selection were distributed non-randomly. ORF1 and ORF2 have experienced strong purifying selection across genotypes. Furthermore, potentially important sites were also found under positive selection in the N-terminal end of ORF2 and the C-terminal end of ORF3. No significant difference was found among the selective pressures on different genotypes.
authors: Department of Epidemiology, School of Public Health, Fourth Military Medical University, Xi'an, China.
authors: Xiaoming
authors: X
authors: Chen
authors: Qian
authors: Q
authors: Zhang
authors: Chao
authors: C
authors: He
authors: Lei
authors: L
authors: Zhang
authors: Jinghua
authors: J
authors: Li
authors: Weilu
authors: W
authors: Zhang
authors: Wei
authors: W
authors: Cao
authors: Yong-Gang
authors: YG
authors: Lv
authors: Zhengcai
authors: Z
authors: Liu
authors: Jing-Xia
authors: JX
authors: Zhang
authors: Zhong-Jun
authors: ZJ
authors: Shao
mesh_terms: D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D016679:Genome, Viral; D005838:Genotype; D016752:Hepatitis E virus / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D011995:Recombination, Genetic; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins