在茄子中鉴定出一种柑橘裂皮类病毒（CEVd）变体，其在棒状二级结构的右末端区域存在96个核苷酸的重复。

Identification in eggplant of a variant of citrus exocortis viroid (CEVd) with a 96 nucleotide duplication in the right terminal region of the rod-like secondary structure.

作者信息

Fadda Z, Daròs J A, Flores R, Duran-Vila N

机构信息

Instituto Valenciano de Investigaciones Agrarias (IVIA), Apartado Oficial, 46113 Moncada, Valencia, Spain.

出版信息

Virus Res. 2003 Nov;97(2):145-9. doi: 10.1016/j.virusres.2003.08.002.

DOI:10.1016/j.virusres.2003.08.002

PMID:14602207

Abstract

Analysis of eggplants, kept for years under greenhouse conditions after having been mechanically inoculated with nucleic acid preparations from field-grown eggplants containing two viroids, Eggplant latent viroid (ELVd) and Citrus exocortis viroid (CEVd), revealed the presence of an additional larger viroid RNA. Molecular characterization of this RNA showed that it is a stable 467-nt variant of CEVd with a 96-nt duplication of the right terminal region (CEVd-D96) that preserves the rod-like secondary structure. The coexistence in eggplant of CEVd (371nt) and CEVd-D96, and the fact that they have an almost identical sequence, strongly suggests the emergence of the latter from the former through an internal recombination mediated by a jumping RNA polymerase with low processivity. CEVd-D96 from eggplant is similar to the CEVd-D92 variant characterized previously in a hybrid tomato, suggesting that certain hosts may play a critical role in selecting and replicating this class of enlarged variants.

摘要

对茄子进行分析，这些茄子在温室条件下保存多年，此前已用来自田间种植的茄子的核酸制剂进行机械接种，这些核酸制剂含有两种类病毒，即茄子潜隐类病毒（ELVd）和柑橘裂皮类病毒（CEVd），结果发现存在一种额外的更大的类病毒RNA。对这种RNA的分子特征分析表明，它是CEVd的一种稳定的467个核苷酸的变体，其右末端区域有96个核苷酸的重复（CEVd-D96），保留了杆状二级结构。CEVd（371个核苷酸）和CEVd-D96在茄子中共存，并且它们具有几乎相同的序列，这强烈表明后者是通过由低持续合成能力的跳跃RNA聚合酶介导的内部重组从前者中产生的。来自茄子的CEVd-D96与先前在杂交番茄中鉴定的CEVd-D92变体相似，这表明某些宿主可能在选择和复制这类扩大的变体中起关键作用。