The paleontology of intergene retrotransposons of maize
The paleontology of intergene retrotransposons of maize
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DOI：
10.1038/1695
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发表时间：
1998-09-01
期刊：
影响因子：
30.8
通讯作者：
Bennetzen, JL
中科院分区：
文献类型：
--
作者：
SanMiguel, P;Gaut, BS;Bennetzen, JL
反转录转座子是一种与动物逆转录病毒相关的转座子，存在于所有真核生物中，并且构成了许多植物基因组的大部分（1-5）。它们的普遍存在表明了它们的重要性，尤其是它们对复杂基因组大规模结构的贡献。在所有高等真核生物中，逆转录元素的出现、激活和扩增的性质和频率尚不清楚。本文采用了一种新的方法，通过比较玉米和高粱中adh1基因的长末端重复序列（LTR）差异，确定了在玉米adh1基因附近发现的23个反转录转座子中的17个的插入日期，以及玉米基因组中未链接位点的另外两个反转录转座子的插入日期。所有被检查的逆转录转座子都是在最近600万年插入的，大多数是在最近300万年插入的。adh的结构？相对于玉米基因组的其他含基因区域，该区域似乎是标准的，因此表明在过去的300万年中，反转录转座子插入使玉米基因组的大小从大约1200 Mb增加到2400 Mb。此外，结果表明，与基因相比，逆转录转座子的突变率增加。
Retrotransposons, transposable elements related to animal retroviruses, are found in all eukaryotes investigated and make up the majority of many plant genomes(1-5). Their ubiquity points to their importance, especially in their contribution to the large-scale structure of complex genomes. The nature and frequency of retro-element appearance, activation and amplification are poorly understood in all higher eukaryotes. Here we employ a novel approach to determine the insertion dates for 17 of 23 retrotransposons found near the maize adh1 gene, and two others from unlinked sites in the maize genome, by comparison of long terminal repeat (LTR) divergences with the sequence divergence between adh1 in maize and sorghum. All retrotransposons examined have inserted within the last six million years, most in the last three million years. The structure of the adh? region appears to be standard relative to the other gene-containing regions of the maize genome, thus suggesting that retrotransposon insertions have increased the size of the maize genome from approximately 1200 Mb to 2400 Mb in the last three million years. Furthermore, the results indicate an increased mutation rate in retrotransposons compared with genes.