Maize centromeres: Organization and functional adaptation in the genetic background of oat
Maize centromeres: Organization and functional adaptation in the genetic background of oat
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DOI：
10.1105/tpc.018937
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发表时间：
2004-03-01
期刊：
影响因子：
11.6
通讯作者：
Jiang, JM
中科院分区：
文献类型：
--
作者：
Jin, WW;Melo, JR;Jiang, JM
多细胞真核生物中的着丝粒DNA序列通常是高度重复的，并且对于特定的着丝粒或对于着丝粒而言不是唯一的。因此，研究植物个体着丝粒的精细结构是一个重大的挑战。我们使用DNA纤维荧光原位杂交方法研究单个玉米（玉米）着丝粒燕麦（燕麦），玉米染色体附加系。附加系中的玉米着丝粒特异性卫星重复CentC使我们能够描绘单个玉米染色体的着丝粒DNA的大小和组织。我们证明，玉米着丝粒的核心主要包含CentC阵列和集群的着丝粒特异性反转录转座子，CRM。CentC和CRM序列高度混合。不同着丝粒的CentC/CRM序列的大小在300 ~>2800 kb之间。CentC和CRM与着丝粒组蛋白H3（CENH 3）的缔合通过在拉伸的着丝粒上的顺序检测程序可视化。分析显示，CENH 3总是与CentC和CRM相关，但并非所有CentC或CRM序列都与CENH 3相关。我们进一步证明，在存在两个CenH 3基因（一个来自燕麦，一个来自玉米）的染色体附加系中，燕麦CENH 3始终被玉米着丝粒掺入。
Centromeric DNA sequences in multicellular eukaryotes are often highly repetitive and are not unique to a specific centromere or to centromeres at all. Thus, it is a major challenge to study the fine structure of individual plant centromeres. We used a DNA fiber-fluorescence in situ hybridization approach to study individual maize (Zea mays) centromeres using oat (Avena sativa)-maize chromosome addition lines. The maize centromere-specific satellite repeat CentC in the addition lines allowed us to delineate the size and organization of centromeric DNA of individual maize chromosomes. We demonstrate that the cores of maize centromeres contain mainly CentC arrays and clusters of a centromere-specific retrotransposon, CRM. CentC and CRM sequences are highly intermingled. The amount of CentC/CRM sequence varies from similar to300 to >2800 kb among different centromeres. The association of CentC and CRM with centromeric histone H3 (CENH3) was visualized by a sequential detection procedure on stretched centromeres. The analysis revealed that CENH3 is always associated with CentC and CRM but that not all CentC or CRM sequences are associated with CENH3. We further demonstrate that in the chromosomal addition lines in which two CenH3 genes were present, one from oat and one from maize, the oat CENH3 was consistently incorporated by the maize centromeres.