Delfino C M, Cerrudo C S, Biglione M, Oubiña J R, Ghiringhelli P D, Mathet V L
Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET) - Universidad de Buenos Aires (UBA), Instituto de Investigaciones en Microbiología y Parasitología Médica, (IMPAM), Ciudad Autónoma de Buenos Aires, Argentina.
Departamento de Ciencia y Tecnología, Laboratorio de Ingeniería Genética y Biología Celular y Molecular - Área Virosis de Insectos (LIGBCM-AVI), Instituto de Microbiología Básica y Aplicada (IMBA), Universidad Nacional de Quilmes, Bernal, Provincia de Buenos Aires, Argentina.
J Viral Hepat. 2018 Jul;25(7):860-869. doi: 10.1111/jvh.12876. Epub 2018 Feb 21.
In association with hepatitis B virus (HBV), hepatitis delta virus (HDV) is a subviral agent that may promote severe acute and chronic forms of liver disease. Based on the percentage of nucleotide identity of the genome, HDV was initially classified into three genotypes. However, since 2006, the original classification has been further expanded into eight clades/genotypes. The intergenotype divergence may be as high as 35%-40% over the entire RNA genome, whereas sequence heterogeneity among the isolates of a given genotype is <20%; furthermore, HDV recombinants have been clearly demonstrated. The genetic diversity of HDV is related to the geographic origin of the isolates. This study shows the first comprehensive bioinformatic analysis of the complete available set of HDV sequences, using both nucleotide and protein phylogenies (based on an evolutionary model selection, gamma distribution estimation, tree inference and phylogenetic distance estimation), protein composition analysis and comparison (based on the presence of invariant residues, molecular signatures, amino acid frequencies and mono- and di-amino acid compositional distances), as well as amino acid changes in sequence evolution. Taking into account the congruent and consistent results of both nucleotide and amino acid analyses of GenBank available sequences (recorded as of January, 2017), we propose that the eight hepatitis D virus genotypes may be grouped into three large genogroups fully supported by their shared characteristics.
丁型肝炎病毒（HDV）与乙型肝炎病毒（HBV）相关，是一种亚病毒因子，可引发严重的急性和慢性肝病。根据基因组核苷酸同一性百分比，HDV最初被分为三种基因型。然而，自2006年以来，原来的分类已进一步扩展为八个进化枝/基因型。整个RNA基因组上的基因型间差异可能高达35%-40%，而给定基因型的分离株之间的序列异质性小于20%；此外，HDV重组体已得到明确证实。HDV的遗传多样性与分离株的地理来源有关。本研究展示了对HDV完整可用序列集的首次全面生物信息学分析，采用了核苷酸和蛋白质系统发育分析（基于进化模型选择、伽马分布估计、树推断和系统发育距离估计）、蛋白质组成分析和比较（基于不变残基的存在、分子特征、氨基酸频率以及单氨基酸和双氨基酸组成距离），以及序列进化中的氨基酸变化。考虑到GenBank中可用序列（截至2017年1月记录）的核苷酸和氨基酸分析结果一致且相符，我们提议，八种丁型肝炎病毒基因型可根据其共同特征分为三个大的基因群组。
