Grappin P, Audeon C, Chupeau M C, Grandbastien M A
Laboratoire de Biologie Cellulaire, INRA-Centre de Versailles, France.
Mol Gen Genet. 1996 Sep 25;252(4):386-97. doi: 10.1007/BF02173003.
A new transposable element of tobacco, Slide, was isolated from the tl mutant line, which shows somatic instability, after its transposition into a locus encoding nitrate reductase (NR). The Slide-124 element is 3733 bp long and its coding sequences show similarities with conserved domains of the transposases of Ac, Tam3 and hobo. Excision from the NR locus is detectable in somatic leaf tissues and Slide mobility is triggered by in vitro tissue culture. Slide excision events create footprints similar to those left by Ac and Tam3. Tobacco lines derived from the tl mutant line seem characterized by unmethylated copies of a few members of the highly repetitive Slide family. Slide mobility was monitored in transient expression assays. In wild-type tobacco protoplasts, the complete Slide element, as well as a defective copy, is able to excise. The complete Slide element, but not the defective version, is able to excise in protoplasts of the heterologous species lettuce (Lactuca sativa). These results show that Slide carries the functions required for its own mobility, and represents the first autonomous Ac-like element characterized in Solanaceae species.
从烟草tl突变体品系中分离出一种新的烟草转座元件Slide，该突变体在转座至编码硝酸还原酶（NR）的位点后表现出体细胞不稳定性。Slide-124元件长3733 bp，其编码序列与Ac、Tam3和hobo转座酶的保守结构域具有相似性。在体细胞叶片组织中可检测到从NR位点的切除，并且Slide的移动性由体外组织培养触发。Slide切除事件产生的足迹类似于Ac和Tam3留下的足迹。源自tl突变体品系的烟草品系似乎以高度重复的Slide家族的一些成员的未甲基化拷贝为特征。在瞬时表达试验中监测了Slide的移动性。在野生型烟草原生质体中，完整的Slide元件以及一个缺陷拷贝都能够切除。完整的Slide元件而非缺陷版本能够在异源物种生菜（Lactuca sativa）的原生质体中切除。这些结果表明Slide具有自身移动所需的功能，并且代表了茄科物种中首个被鉴定的自主Ac样元件。
