Fedoroff N V, Smith D L
Carnegie Institution of Washington, Department of Embryology, Baltimore, MD 21210.
Plant J. 1993 Feb;3(2):273-89. doi: 10.1111/j.1365-313x.1993.tb00178.x.
The maize transposable element Activator (Ac) has been shown to be active in a number of dicots, including Arabidopsis thaliana, whose small genome and short generation time have favored its wide adoption as a model organism for molecular genetic approaches to plant physiology and development. Using the Ac element and several bacterial and plant marker genes, we have devised a versatile system for identifying plants in which a transposon has excised and reinserted elsewhere in the genome. The transposons have been designed to facilitate the identification of insertions downstream of promoters and in the vicinity of enhancers by the inclusion of a beta-glucuronidase (GUS) gene either lacking a promoter or having a minimal promoter sequence. The system permits the transposon and the source of transposase to be maintained either stably in separate plants or in the same plant. Plants in which transposition is occurring can be identified by the frequent somatic activation of the GUS gene. The herbicide chlorsulfuron is used as a selective agent to identify progeny plants in which the transposon has excised from its original insertion site within a chlorsulfuron-resistant acetolactate synthase gene. Additional selectable markers permit the identification of plants containing a transposed element, but lacking transposase. Here we describe our initial characterization of the system and demonstrate its reliability and efficiency in identifying plants with transposed elements.
玉米转座因子激活子（Ac）已被证明在多种双子叶植物中具有活性，包括拟南芥。拟南芥基因组小、世代时间短，这使得它被广泛用作研究植物生理学和发育的分子遗传学方法的模式生物。利用Ac因子以及几个细菌和植物标记基因，我们设计了一个通用系统，用于鉴定转座子已从基因组中的一个位置切除并重新插入到其他位置的植物。这些转座子的设计通过包含一个缺少启动子或具有最小启动子序列的β-葡萄糖醛酸酶（GUS）基因，便于鉴定启动子下游和增强子附近的插入情况。该系统允许转座子和转座酶来源在不同植物中稳定维持，也可以在同一植物中维持。正在发生转座的植物可以通过GUS基因的频繁体细胞激活来鉴定。除草剂氯磺隆用作选择剂，以鉴定转座子已从抗氯磺隆乙酰乳酸合酶基因内的原始插入位点切除的后代植物。其他选择标记允许鉴定含有转座元件但缺乏转座酶的植物。在此，我们描述了该系统的初步特征，并证明了其在鉴定含有转座元件的植物方面的可靠性和效率。
