1] Department of Plant Developmental Genetics, Institute of Biophysics ASCR, Brno, Czech Republic [2] Laboratory of Genome Dynamics, CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
Heredity (Edinb). 2013 Oct;111(4):314-20. doi: 10.1038/hdy.2013.51. Epub 2013 May 29.
We analysed the size, relative age and chromosomal localization of nuclear sequences of plastid and mitochondrial origin (NUPTs-nuclear plastid DNA and NUMTs-nuclear mitochondrial DNA) in six completely sequenced plant species. We found that the largest insertions showed lower divergence from organelle DNA than shorter insertions in all species, indicating their recent origin. The largest NUPT and NUMT insertions were localized in the vicinity of the centromeres in the small genomes of Arabidopsis and rice. They were also present in other chromosomal regions in the large genomes of soybean and maize. Localization of NUPTs and NUMTs correlated positively with distribution of transposable elements (TEs) in Arabidopsis and sorghum, negatively in grapevine and soybean, and did not correlate in rice or maize. We propose a model where new plastid and mitochondrial DNA sequences are inserted close to centromeres and are later fragmented by TE insertions and reshuffled away from the centromere or removed by ectopic recombination. The mode and tempo of TE dynamism determines the turnover of NUPTs and NUMTs resulting in their species-specific chromosomal distributions.
我们分析了六个完全测序的植物物种中质体和线粒体起源的核序列（NUPTs-核质体 DNA 和 NUMTs-核线粒体 DNA）的大小、相对年龄和染色体定位。我们发现，在所有物种中，最大的插入片段与细胞器 DNA 的差异比短插入片段更小，表明它们是最近起源的。最大的 NUPT 和 NUMT 插入片段定位于拟南芥和水稻小基因组的着丝粒附近。它们也存在于大豆和玉米大基因组的其他染色体区域。NUPTs 和 NUMTs 的定位与拟南芥和高粱中转座元件 (TEs) 的分布呈正相关，与葡萄和大豆呈负相关，与水稻或玉米无关。我们提出了一个模型，其中新的质体和线粒体 DNA 序列插入到着丝粒附近，然后被 TEs 的插入片段碎片化，并从着丝粒重新排列或通过异位重组去除。TE 动态的模式和时空调控决定了 NUPTs 和 NUMTs 的周转率，从而导致它们在物种特异性染色体分布上的差异。
