title: CpG islands of hepatitis B virus genome isolated from Chinese patients.
abstract: There are differences in the distribution and length of HBV CpG islands and the viral mutations contribute greatly to the development of HBV-related diseases. However, little is known regarding the effects of such difference and mutations in HBV genotypes B and C sequences on the regulation of HBV gene expression and their clinical outcomes. To study the distribution, length and genetic trait of CpG islands in normal and mutant sequences of HBV genotypes B and C, 320 HBV isolates from Chinese patients were retrieved from GenBank. Programs CLUSTALX 1.83 and MethPrimer were employed to perform multiple sequence alignments and to predict CpG islands, respectively. 72.0% genotype B isolates contained three conventional CpG islands, and 76.1% genotype C only contained CpG islands II and III. 14.6% genotype B and 7.5% genotype C contained three novel CpG islands. In genotype B, lengths of conventional CpG islands between normal and mutant isolates exhibited substantial variations, but in genotype C, those were relatively stable. CpG island II could be "truncated" or "split". "Truncated" region mutations were associated with structural and functional abnormalities of HBV genes. Rate of "split" CpG island II in genotype B was much higher than that in genotype C. In the majority of isolates from HCC and HBV-ACLF, genotype C lacked CpG island I and novel islands. Distribution, length and genetic trait of CpG islands in HBV genotypes B and C might affect their methylation status, and further affect regulation of HBV gene expression, leading to different clinical outcomes.
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China.
authors: Zhiwei
authors: Z
authors: Hou
authors: Jinxin Research Institute for Reproductive Medicine and Genetics, Chengdu Jinjiang Hospital for Maternal and Child Health Care, Chengdu 610000, China.
authors: Jihua
authors: J
authors: Huang
authors: Faculty of Science and Engineering, University Paul Sabatier, Toulouse 31062, France.
authors: Chengyao
authors: C
authors: Zhong
authors: Key Laboratory of Birth Defects and Reproductive Health of National Health and Family Planning Commission, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 400020, China.
authors: Lianbing
authors: L
authors: Li
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China.
authors: Qingdong
authors: Q
authors: Xie
authors: Key Laboratory of Birth Defects and Reproductive Health of National Health and Family Planning Commission, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 400020, China.
authors: Mingfu
authors: M
authors: Ma
authors: Jinxin Research Institute for Reproductive Medicine and Genetics, Chengdu Jinjiang Hospital for Maternal and Child Health Care, Chengdu 610000, China.
authors: Tingting
authors: T
authors: Han
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China.
authors: Degang
authors: D
authors: Wang
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China.
authors: Martin
authors: M
authors: Maldonado
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China.
authors: Lan
authors: L
authors: Xu
authors: Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, China. Electronic address: thhuang@stu.edu.cn.
authors: Tianhua
authors: T
authors: Huang
authors: Jinxin Research Institute for Reproductive Medicine and Genetics, Chengdu Jinjiang Hospital for Maternal and Child Health Care, Chengdu 610000, China. Electronic address: yzhong08@126.com.
authors: Ying
authors: Y
authors: Zhong
mesh_terms: D044466:Asian People / Q000235:genetics; D002681:China; D018899:CpG Islands; D019175:DNA Methylation; D016679:Genome, Viral; D005838:Genotype; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008107:Liver Diseases / Q000821:virology*; D009154:Mutation
keywords: CpG island; DNA methylation; Genotype; Hepatitis B virus; Mutation