ABUNDANCE AND DNA-SEQUENCE OF 2-BASE REPEAT REGIONS IN TROPICAL TREE GENOMES
ABUNDANCE AND DNA-SEQUENCE OF 2-BASE REPEAT REGIONS IN TROPICAL TREE GENOMES
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DOI：
10.1139/g91-011
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发表时间：
1991-02-01
期刊：
影响因子：
3.1
通讯作者：
HUBBELL, SP
中科院分区：
文献类型：
--
作者：
CONDIT, R;HUBBELL, SP
双碱基串联重复序列由于其丰富性和长度变异性而成为群体遗传学研究的重要工具。 作为我们对热带森林植物生态学研究的一部分，我们开始了对几个热带树木属中的二核苷酸重复区的研究。 用寡核苷酸探针poly（GT）和poly（AG）筛选细菌期λ中的基因组文库。 这两种类型的重复区域是丰富的所有六种植物的基因组检查。 使用噬菌体文库中插入片段的大小和筛选的噬菌体数量，我们估计每个基因组有5 × 10（3）至3 × 10（5）个聚（AC）和聚（AG）位点，其中AG位点略多于AC位点。 当文库由基因组DNA的较小片段制成时，丰度估计较高，表明两个碱基重复位点在基因组中聚集。 Poly（AC）位点的长度为16-22 bp，测序的5个中有4个邻近poly（AG）或poly（AT）位点。 其他重复区域出现在AC位点两侧的DNA中。 这进一步证明了两个碱基重复序列和其他重复序列在基因组中是成簇的。 双碱基重复序列在植物基因组中大量存在，可以为植物群体遗传学研究提供大量的多态性标记。
Tandem DNA repeats of two-base pairs are potentially important tools for population genetic studies because of their abundance and length variation. As part of our research into the ecology of tropical forest plants, we began a study of dinucleotide repeat regions in several genera of tropical trees. Genomic libraries in bacteriophase lambda were screened with the oligonucleotide probes poly(GT) and poly(AG). Both types of repeat regions were abundant in the genomes of all six plant species examined. Using the size of inserts in the phage libraries and number of phage screened, we estimated that there were 5 x 10(3) to 3 x 10(5) poly(AC) and poly(AG) sites per genome, with slightly more AG than AC sites. When libraries were made from smaller fragments of genomic DNA, abundance estimates were higher, suggesting that two-base repeat sites were clustered in the genome. Poly(AC) sites were 16-22 bp in length, and four of the five sequenced were adjacent to either poly(AG) or poly(AT) sites. Other repeat regions appeared in DNA flanking the AC sites. This further demonstrated that two-base repeats and other repetive DNA were clustered in the genome. Two-base repeats are abundant in plant genomes and could provide a large number of polymorphic markers for studies of plant population genetics.