Construction and behavior of engineered minichromosomes in maize
Construction and behavior of engineered minichromosomes in maize
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DOI：
10.1073/pnas.0700932104
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发表时间：
2007-05-22
影响因子：
11.1
通讯作者：
Birchler, James A.
中科院分区：
文献类型：
--
作者：
Yu, Weichang;Han, Fangpu;Birchler, James A.
通过修饰天然的A染色体和额外的B染色体，在玉米中构建了工程微染色体。通过使用端粒介导的染色体截短，它被证明，这样的方法是可行的正常A染色体的minichromosornes通过选择自发的多倍体事件，补偿所产生的缺陷的一代。B染色体很容易通过截短质粒的基因枪转化而分离。外源基因从整合到正常B染色体和从截短的miniB染色体中忠实地表达。证明了miniA染色体上的末端转基因与正常染色体上的末端位点之间的位点特异性重组。还发现miniA染色体在减数分裂期间不与其祖先染色体配对，表明此类构建体的有用性质。小B染色体忠实地从一代传递到下一代，但在正常B染色体存在的情况下可以改变剂量。这种构建工程染色体的方法可以很容易地扩展到其他植物物种，因为它不依赖于克隆的着丝粒序列，这是物种特异性的。这些平台将为植物染色体结构和功能的研究以及生物技术和农业的未来发展提供途径。
Engineered minichromosomes were constructed in maize by modifying natural A and supernumerary B chromosomes. By using telomere-mediated chromosomal truncation, it was demonstrated that such an approach is feasible for the generation of minichromosornes of normal A chromosomes by selection of spontaneous polyploid events that compensate for the deficiencies produced. B chromosomes are readily fractionated by biolistic transformation of truncating plasmids. Foreign genes were faithfully expressed from integrations into normal B chromosomes and from truncated miniB chromosomes. Site-specific recombination between the terminal transgene on a miniA chromosome and a terminal site on a normal chromosome was demonstrated. It was also found that the miniA chromosome did not pair with its progenitor chromosomes during meiosis, indicating a useful property for such constructs. The miniB chromosomes are faithfully transmitted from one generation to the next but can be changed in dosage in the presence of normal B chromosomes. This approach for construction of engineered chromosomes can be easily extended to other plant species because it does not rely on cloned centromere sequences, which are species-specific. These platforms will provide avenues for studies on plant chromosome structure and function and for future developments in biotechnology and agriculture.