Fawcett Jeffrey A, Kawahara Taihachi, Watanabe Hitoshi, Yasui Yasuo
Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwakecho, Sakyoku, Kyoto 606-8502, Japan.
Plant Mol Biol. 2006 Jun;61(3):505-14. doi: 10.1007/s11103-006-0026-7.
The distribution and evolution of Au SINE in plants were examined. Au SINE is a short interspersed element first identified in Aegilops umbellulata, a close relative of wheat. The Au SINE was previously found in species such as wheat, maize, tobacco, and tomato, but not in rice. In this study, we first searched public databases, and next examined the presence of Au in a broad range of plant species by PCR using internal primers of Au. Although Au is likely to be absent from many species including rice, it was identified in many Gramineae, Solanaceae, and Fabaceae species, and also in a basal angiosperm species, Asimina triloba. Phylogenetic studies suggest that Au SINE originated before the divergence of monocots and eudicots. Au SINE sequences of Asimina, Triticum, Zea, Nicotiana, Lotus, Medicago, and Glycine were aligned and compared. Although sequences of Au were highly conserved among distantly related species, every Au element in Glycine had a 16 bp deletion and its 3' end differed from sequences of other species. This type of Au could only be found in G. max, and not in other species including other Fabaceae species such as M. truncatula and L. japonicus. This is the first report of a plant SINE family present in multiple lineages, and the evolution of Au SINE in the plant kingdom, especially in Gramineae and Fabaceae is discussed.
研究了植物中Au SINE的分布与进化。Au SINE是一种短散在重复元件，最初在小麦的近缘种伞穗山羊草中被鉴定出来。此前在小麦、玉米、烟草和番茄等物种中发现了Au SINE，但在水稻中未发现。在本研究中，我们首先搜索了公共数据库，然后使用Au的内部引物通过PCR检测了多种植物物种中Au的存在情况。尽管包括水稻在内的许多物种可能不存在Au，但在许多禾本科、茄科和豆科物种以及一种基部被子植物物种——北美番荔枝中都鉴定到了Au。系统发育研究表明，Au SINE起源于单子叶植物和双子叶植物分化之前。对北美番荔枝、小麦、玉米、烟草、百脉根、苜蓿和大豆的Au SINE序列进行了比对和比较。尽管Au的序列在亲缘关系较远的物种中高度保守，但大豆中的每个Au元件都有一个16 bp的缺失，其3'端与其他物种的序列不同。这种类型的Au仅在大豆中发现，在包括其他豆科物种如蒺藜苜蓿和日本百脉根在内的其他物种中未发现。这是关于一个存在于多个谱系中的植物SINE家族的首次报道，并讨论了Au SINE在植物界，特别是在禾本科和豆科中的进化情况。
