GDR977 BIOMOVE CNRS, Université Blaise-Pascal, 24, Avenue des Landais, 63177, Aubiere Cedex, France.
Theor Appl Genet. 1995 Jul;91(1):160-8. doi: 10.1007/BF00220873.
The major simple sequence repeats present in the Arabidopsis genome were identified by Southern hybridizations with 49 oligonucleotide probes matching all the possible combinations of motifs up to 4 nucleotides long. The method used allowed us to perform all the hybridizations under the same temperature conditions. A good correlation was observed with the data obtained from database analysis, indicating that the method can be useful for identifying the major classes of microsatellite loci in species for which few or no sequence data are available. AG/CT, AAG/CTT, ATG/CAT and GTG/CAC are the major motifs present in the Arabidopsis genome that can be used as convenient probes to isolate microsatellite loci by screening libraries. AAG/CTT is the more frequent of these motifs, and its relative frequency in Arabidopsis is much higher than averagely found in the plant kingdom. About 8% of the cDNA clones from an immature silique library contains AG/CT, AAG/CTT or ATG/CAT microsatellite loci. Several microsatellite loci were isolated by screening genomic and cDNA libraries. Twenty-six tri-nucleotide loci were PCR amplified from four different ecotypes, and polymorphism was observed for 12 of them; 10 loci showing two alleles and 2 loci showing three alleles.
通过 Southern 杂交实验，用 49 个寡核苷酸探针与所有可能的 4 个核苷酸长的基序组合进行匹配，鉴定出拟南芥基因组中的主要简单序列重复。所使用的方法允许我们在相同的温度条件下进行所有杂交实验。与从数据库分析中获得的数据观察到了很好的相关性，表明该方法可用于鉴定在缺乏或几乎没有序列数据的物种中主要的微卫星基因座类别。在拟南芥基因组中，出现频率较高的主要基序为 AG/CT、AAG/CTT、ATG/CAT 和 GTG/CAC，可用作筛选文库时分离微卫星基因座的便捷探针。在这些基序中，AAG/CTT 的出现频率更高，在拟南芥中的相对频率远高于植物界的平均水平。从一个未成熟的子房文库中获得的约 8%的 cDNA 克隆包含 AG/CT、AAG/CTT 或 ATG/CAT 微卫星基因座。通过筛选基因组和 cDNA 文库，分离出了多个微卫星基因座。从四个不同的生态型中扩增了 26 个三核苷酸基因座，其中 12 个表现出多态性；10 个基因座表现出两个等位基因，2 个基因座表现出三个等位基因。
