喜姆比蘭崁紋病毒台灣系統基因序列譯讀與分析

Molecular Sequencing and Analysis of the Viral Genome of Cymbidium Mosaic Virus Taiwan Strain

王惠亮(H. L. Wang) ； 林偉志(W. C. Lin)

《植物病理學會刊》 13卷1期 (2004/03) Pp. 61-68

https://doi.org/10.6649/PPB.200403_13(1).0007

摘要

喜姆比蘭嵌紋病毒（Cymbidium mosaic virus, CymMV），是感染蘭科植物最重要的病毒，在分類上屬於馬鈴薯X屬（genus Potexvirus），為一種長絲狀的病毒，其顆粒大小約為13×490 nm。由蝴蝶蘭（Phalaenopsis）獲得之分離株（CymMV-TW）經病毒純化，病毒核酸萃取後，以RT-PCR選殖，經核苷酸序列譯讀後得到CymMV-TW全長度核苷酸序列6227個核苷酸（accesion number: AY571289），其中RdRp（RNA-dependent RNA polymerase）基因4254個核苷酸，可轉譯成1417個胺基酸，分子量為159,956 Da、TGB1（triple-gene-block 1）基因690個核苷酸，可轉譯成229個胺基酸，分子量為159,863 Da、TGB2（triple-gene-block 2）基因339個核苷酸，可轉譯成112個胺基酸，分子量為12,474 Da、TGB3（triple-gene-3）基因276個核苷酸，可轉譯成91個胺基酸，分子量為9,682 Da、CP（coat protein）基因672個核苷酸，可轉譯成223個胺基酸，分子量為23,808 Da、5’端非轉譯區73個核苷酸和3’端非轉譯區74個核苷酸。CymMV-TW（台灣系統）與CymMv-K2（韓國系統）及CymMV-S1（新加坡系統）作全長度核苷酸序列及五個基因核苷酸、胺基酸序列比對，結果顯示三者為同種病毒之不同系統。但是泰國與法國系統的CP基因核苷酸序列，和上述三個系統及馬來西亞系統之比較只有49～53%相同度。

關鍵字

喜姆比蘭崁紋病毒 ； 開放轉譯架構 ； 核苷酸序列

並列摘要

Cymbidium mosaic virus (CymMV) is a member of genus Potexvirus in the family Potexviridae. The purpose of this study was to sequence the genomic regions of a domestic CymMV stain (CymMV-TW), and compare its nucleotide and amino acid sequences with those of two reported strains, K2 from Korea and S1 from Singapore, of CymMV. Full-length nucleotide sequences obtained from cDNA clones of CymMV-TW genome was 6227 and was highly homologous (97%) to that of two reported strains. No significant differences were observed in the length and sequence of the RNA of the three CymMV strains. All comprise of a 5’-NTR, 5 ORFs, and a 3’ NTR. The RNA molecules contain identical nucleotide numbers in the ORFs of their RdRp, TGB2, TGB3 and CP genes, but vary in length in their TGB1 ORF and NTRs which indicated that all three are different strains of the same virus. The comparison of multiple alignments of nucleotide and amino acid sequences among CymMV strains displayed high identities in intraspecies. Phylogenetic analysis revealed that CymMV-Tw was mor relaed to CymMV-S1 than to CymMV-K2.

並列關鍵字

Cymbidium mosaic virus ； open reading frame ； nucleotide sequences