Isolation and characterization of a 1.7-kb transposable element from a mutator line of maize.
Isolation and characterization of a 1.7-kb transposable element from a mutator line of maize.
复制标题
从玉米突变系中分离和表征 1.7-kb 转座元件。
DOI：
10.1093/genetics/117.2.297
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发表时间：
1987
期刊：
影响因子：
3.3
通讯作者：
Walbot,V
中科院分区：
文献类型：
--
作者：
Taylor,LP;Walbot,V
我们从玉米 Mutator 品系中克隆并测序了一个 1.7 kb Mu 元件，并将其结构与 1.4 kb 元件 Mu1 进行了比较。除了 1.7 kb 元件中存在的 385 bp DNA 块外，这些转座元件在结构上相似，共享末端倒置序列和内部直接重复序列。 Mu1.7 中额外 DNA 的一部分是 1.4-kb 元件中截短的同向重复序列的一部分，这表明通过删除内部序列可以从 1.7-kb 类衍生出 1.4-kb 元件。与该额外DNA的一部分同源的丰富的poly(A)+RNA存在于突变系和非突变系的多个组织中。对基因外显子中插入的含有 Mu1.7 元件的不稳定突变体青铜 1(bz) 等位基因的转录物进行分析，检测到与 aBz1(青铜) 基因探针杂交的三种 Poly(A)+RNA：最大的包含 Bz1 基因转录物中的整个 Mu1.7 元件；另一个似乎是剪接的嵌合转录本；最小的是正常大小的Bz1mRNA。后者很可能是由表达紫色素的组织的 Southern 分析检测到的正常大小的等位基因编码的，这表明通过切除 Mu1.7 元件可以恢复正常的基因功能。
We have cloned and sequenced a 1.7-kbMuelement from a Mutator line of maize and compared its structure toMu1, a 1.4-kb element. With the exception of a 385-bp block of DNA present in the 1.7-kb element, these transposable elements are structurally similar, sharing terminally inverted and internal direct repeated sequences. Derivation of 1.4-kb elements from the 1.7-kb class via deletion of internal sequence is suggested by the finding that a portion of the extra DNA inMu1.7is part of a truncated direct repeat sequence in the 1.4-kb element. An abundant poly(A)+RNA homologous to a portion of this extra DNA is present in several tissues of both Mutator and non-Mutator lines. Analysis of transcripts from an unstable mutantbronze1(bz) allele containing aMu1.7element inserted in an exon of the gene detects three species of poly(A)+RNA that hybridize to aBz1(Bronze) gene probe: the largest contains the entireMu1.7element in theBz1gene transcript; another appears to be a spliced, chimeric transcript; the smallest is normal sizeBz1mRNA. The latter is most likely encoded by the normal-size alleles detected by Southern analysis of tissue expressing purple pigment, suggesting that normal gene function is restored by excision of theMu1.7element.