Complete Nucleotide Sequence of RNA2 of Cucurbit chlorotic yellows virus Isolated from Melons in Taiwan and Its Comparisons with Currently Existing Isolates

台灣瓜類退綠黃化病毒RNA2之全長核苷酸序列及其與現有株系的比較

林羿廷(Yi-Ting Lin) ； 廖吉彥(Jye-Yann Liao) ； 蔡錦慧(Chin-Hui Tsai) ； 鄧汀欽(Ting-Chin Deng)

《台灣農業研究》 61卷2期 (2012/06) Pp. 132-143

https://doi.org/10.6156/JTAR/2012.06102.06

摘要

瓜類退綠黃化病毒（Cucurbit chlorotic yellows virus, CCYV） 雲林縣二崙鄉分離株 （CCYV-Erlun）與宜蘭縣壯圍鄉分離株（CCYV-Yilan），以反轉錄聚合酶鏈式反應（RT-PCR）及Rapid amplificationof 5' complementary DNA ends（5' RACE）等方法將其RNA2完全解序，各得全長為8041 bp之核苷酸序列；除 5'- 和 3'- 未轉譯端外，包括p4.9基因（132 nt）、HSP70h基因 （1671 nt）、p6 基因（165nt）、p59基因（1554 nt）、p9基因（240 nt）、CP基因（753 nt）、CPm基因（1425 nt）及p26基因（642nt）。利用其中CP基因序列設計引子對進行RT-PCR，可提高 CCYV檢測的敏感性與準確性。藉由RNA2核苷酸序列比對及親緣分析，結果顯示於台灣發現之CCYV-Erlun （JN126045）及CCYVYilan（JN126046）都與日本、台灣、中國及蘇丹之CCYV相關核苷酸序列相同度達99-100%。熵圖（Entropy plot）顯示兩個台灣分離株與日本原始分離株的RNA2核苷酸差異只有12 nt（在總數8041 nt 中），且主要都發生在5'- 及3'- 端未轉譯區。本研究發現目前全球各地發生之CCYV分離株彼此間基因同質性極高，親緣關係非常近，因此推論這些病毒都是同一來源。

關鍵字

瓜類退綠黃化病毒 ； 反轉錄聚合酶鏈式反應 ； 親緣分析 ； 熵圖

並列摘要

The nucleotides of genomic RNA2 of Cucurbit chlorotic yellows virus (CCYV) isolates CCYV-Erlun (JN126045) and CCYV-Yilan (JN126046) collected from Taiwan were completely sequenced. In addition to 5'- and 3'- terminal untranslated regions, a total of 8041 bp in length encoding genes of p4.9 (132 nt), HSP70h (1671 nt), p6 (165 nt), p59 (1554 nt), p9 (240 nt), CP (753 nt), CPm (1425 nt), and p26 (642 nt) were determined by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of 5' complementary DNA ends (5'-RACE). The CP gene-targeted primers for RT-PCR would be useful for improving the sensitivity and accuracy of CCYV detection. Comparative analyses of the nucleotide sequences of CCYV isolates with those of various geographic origins including Japan, Taiwan, China, and Sudan revealed that the identities are as high as 99% to 100% in respective genes of HSP70h, CP, CPm and entire RNA2. Entropy plotting demonstrated the variability of nucleotide sequences among two Taiwan isolates and an initial Japan isolate had only 12 divergent nt in a total of 8041 nt of RNA2, and the nucleotide sequence variance located mainly in the 5'- and 3'- terminal regions. The remarkable homogeneity and very close cluster of all CCYV nucleotide sequences available for the phylogenetic analyses indicate that all the currently existing CCYV isolates in the world were originated from the same source.

並列關鍵字

CCYV ； RT-PCR ； Phylogenetic analysis ； Entropy plot