Fedoroff N V, Banks J A
Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210.
Genetics. 1988 Oct;120(2):559-77. doi: 10.1093/genetics/120.2.559.
We report the results of genetic studies on derivatives of two different alleles of the maize a locus with an insertion of the Suppressor-mutator (Spm) transposable element in which the element is inactive, but can be reactivated readily. We present evidence that the mechanism that determines whether the element is in an active or inactive phase has two genetically distinguishable components. One determines whether or not the element is genetically active (the phase setting) and the other determines the stability of the setting in development, its heritability, and its phase in the next generation (the phase program). We show that the element's phase can be reset in a reproducible pattern during plant development. We also show that the Spm element can be reprogrammed to undergo a subsequent phase change without a concomitant phase change. The capacity to reset and reprogram the Spm element is differentially expressed within the plant in a pattern that is correlated with the developmental fate of apical and lateral meristems, suggesting the involvement of a basic developmental determination mechanism.
我们报告了对玉米a位点两个不同等位基因衍生物的遗传研究结果，这些衍生物带有抑制-突变体（Spm）转座元件的插入，其中该元件处于无活性状态，但可轻易重新激活。我们提供的证据表明，决定该元件处于活性或非活性阶段的机制有两个在遗传上可区分的组成部分。一个决定元件是否具有遗传活性（阶段设定），另一个决定设定在发育过程中的稳定性、其遗传性以及在下一代中的阶段（阶段程序）。我们表明，在植物发育过程中，元件的阶段可以以可重复的模式重置。我们还表明，Spm元件可以被重新编程以经历随后的阶段变化，而不会伴随同时发生的阶段变化。重置和重新编程Spm元件的能力在植物体内以与顶端和侧生分生组织的发育命运相关的模式差异表达，这表明涉及一种基本的发育决定机制。
