Ma Y P, Ruan Q, Ji Y H, Wang N, Li M L, Qi Y, He R, Sun Z R, Ren G W
Virus Laboratory, The Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning, PR China.
Genet Mol Res. 2011 Apr 5;10(2):566-75. doi: 10.4238/vol10-2gmr1059.
Human cytomegalovirus (HCMV) is a double-stranded DNA virus with the largest genome (~235 kb) of the known human herpes viruses. The coding potential and transcript structures of most HCMV predicted genes have not been identified. New or unknown genes could exist in clinical strains. The SMART (switching mechanism at 5' end of RNA template of reverse transcriptase) technique was used to construct a full-length cDNA library of an HCMV clinical strain in the late expression phase. Randomly selected clones were sequenced. The sequenced expressed sequence tags were used to identify the expression and transcript structures of some predicted and unpredicted genes of HCMV. The transcripts of the UL99, TRL5/IRL5, UL73 to UL75, UL4, and UL115 genes, which were previously detected, were obtained with full-length structures from this library. Some novel transcripts, including several transcripts of UL/b' genes and three antisense transcripts of UL83, UL87 and UL31 were found. The novel transcripts that were found, particularly the antisense transcripts of UL83, UL87 and UL31, showed that the transcription of HCMV genes is more complex than previously predicted. Our study highlights the usefulness of the full-length cDNA library for discovering new genes and transcripts of HCMV.
人巨细胞病毒（HCMV）是一种双链DNA病毒，在已知的人类疱疹病毒中拥有最大的基因组（约235 kb）。大多数HCMV预测基因的编码潜能和转录结构尚未确定。临床毒株中可能存在新的或未知的基因。利用SMART（逆转录酶RNA模板5'端的切换机制）技术构建了处于晚期表达阶段的HCMV临床毒株的全长cDNA文库。对随机挑选的克隆进行测序。测序得到的表达序列标签用于鉴定HCMV一些预测和未预测基因的表达及转录结构。从该文库中获得了先前检测到的UL99、TRL5/IRL5、UL73至UL75、UL4和UL115基因的具有全长结构的转录本。发现了一些新的转录本，包括几个UL/b'基因的转录本以及UL83、UL87和UL31的三个反义转录本。所发现的新转录本，特别是UL83、UL87和UL31的反义转录本，表明HCMV基因的转录比先前预测的更为复杂。我们的研究突出了全长cDNA文库在发现HCMV新基因和转录本方面的作用。
