title: Polymorphisms of human cytomegalovirus UL148A, UL148B, UL148C, UL148D genes in clinical strains.
abstract: BACKGROUND
  Clinical isolates of human cytomegalovirus (HCMV) display polymorphisms in multiple genes. Some authors have suggested that polymorphisms are implicated in HCMV-induced immunopathogenesis, as well as in strain-specific behaviors, such as tissue-tropism and the ability to establish persistent or latent infections.
  
  
  OBJECTIVE
  To describe the features of HCMV UL148A, UL148B, UL148C and UL148D open reading frames (ORFs) and the variable sites within the frames in clinical strains.
  
  
  METHODS
  PCR was performed to amplify these ORFs in 22 clinical strains. PCR amplification products were sequenced directly and analyzed.
  
  
  RESULTS
  The nucleotide diversity of UL148A, UL148B, UL148C and UL148D ORFs in studied strains is 0.5-8.3%, 0.5-4.6%, 0.5-3% and 1.7-8.1%, respectively; the amino acid diversity of their putative proteins is 1.3-6.3%, 1.3-5.0%, 1.3-3.9% and 1.7-8.1%, respectively, related to the Merlin strain. The modification sites of UL148A, UL148B, UL148C and UL148D predicted proteins from strains in unpassaged urine samples were conserved, except for strain U96, compared with that of the Merlin strain. By phylogenetic and statistical analysis, the UL148A and UL148D sequences of clinical strains were classified into three groups.
  
  
  CONCLUSIONS
  Compared to the UL148A, UL148B and UL148D ORFs, the UL148C ORF was relatively conserved, as was the amino acid sequence of the UL148C putative protein. Isolates that have been passaged several times in human embryonic lung fibroblasts (HELF) showed some changes of modification sites, however. A discrete linkage was found between the groups of UL148A gene and those of UL148D gene.
authors.affiliation: Virus Laboratory, The Second Affiliated Hospital of China Medical University, No. 36, Sanhao Street, Heping District, Shenyang, Liaoning 110004, PR China.
authors.forename: Yao Hua
authors.initials: YH
authors.lastname: Ji
authors.forename: Zheng
authors.initials: Z
authors.lastname: Rong Sun
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ruan
authors.forename: Jin Jin
authors.initials: JJ
authors.lastname: Guo
authors.forename: Rong
authors.initials: R
authors.lastname: He
authors.forename: Ying
authors.initials: Y
authors.lastname: Qi
authors.forename: Yan Ping
authors.initials: YP
authors.lastname: Ma
authors.forename: Zhi Qin
authors.initials: ZQ
authors.lastname: Mao
authors.forename: Yu Jing
authors.initials: YJ
authors.lastname: Huang
mesh_terms: D003587:Cytomegalovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000635:transmission / Q000821:virology*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D016366:Open Reading Frames; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA