n nnnComposite or closely linked maize (Zea mays) Ac/Ds transposableelements can induce chromosome breakage, but the precise configurationsof Ac/Ds elements that can lead to chromosome breakage are notcompletely defined. Here, we determined the structures and chromosomebreakage properties of 15 maize p1 alleles: each allele containsa fixed fractured Ac (fAc) element and a closely linked full-lengthAc at various flanking sites. Our results show that pairs ofAc/fAc elements in which the termini of different elements arein direct or reverse orientation can induce chromosome breakage.By contrast, no chromosome breakage is observed with allelescontaining pairs of Ac/fAc elements in which the external terminiof the paired elements can function as a macrotransposon. Amongthe structures that can lead to chromosome breaks, breakagefrequency is inversely correlated with the distance betweenthe interacting Ac/Ds termini. These results provide new insightinto the mechanism of transposition-induced chromosome breakage,which is one outcome of the chromosome-restructuring abilityof alternative transposition events.展开▼
机译：ABSTRACTn n
n TOP n <字体颜色= 464c53>抽象 n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n n nnn复合或紧密连锁的玉米（ Zea mays ） Ac / Ds 可转座 元素可以诱导染色体断裂，但是可以导致染色体断裂的 Ac / Ds 元素的精确配置 不是 完全定义。在这里，我们确定了15个玉米 p1 等位基因的结构和染色体 断裂特性：每个等位基因均包含 固定断裂的 Ac （ fAc ）元素和在各个侧翼位点紧密连接的全长 Ac 。我们的结果表明，成对的 Ac / fAc 元素对（其中不同元素的末端为 ）可以诱导染色体断裂。相比之下，等位基因 包含成对的 Ac / fAc 元素对（其中的外部末端 ）没有观察到染色体断裂配对的元件可以充当宏转座子。在可能导致染色体断裂的 结构中，断裂 的频率与相互作用的 Ac / Ds之间的距离与 之间的距离成反比。我>总站。这些结果为 对转座诱导的染色体断裂的机制提供了新的认识， 是替代性转座事件的染色体重构能力 的结果之一。 。展开▼
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011|Department of Agronomy, Iowa State University, Ames, Iowa 50011;
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011|Department of Agronomy, Iowa State University, Ames, Iowa 50011;
School of Biological Sciences, Illinois State University, Normal, Illinois 61790;
School of Biological Sciences, Illinois State University, Normal, Illinois 61790;
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011|Department of Agronomy, Iowa State University, Ames, Iowa 50011;
