Taramino G, Tingey S
Agricultural Products Department, E.I. du Pont de Nemours and Co. (Inc.), Wilmington, DE 19880-0402, U.S.A.
Genome. 1996 Apr;39(2):277-87. doi: 10.1139/g96-038.
Simple sequence repeats (SSRs) are a relatively new class of DNA markers consisting of short runs of tandemly repeated sequence motifs evenly distributed throughout eukaryotic genomes. Owing to the high rate of variation in the number of repeat units, the polymorphism level shown by SSRs is high. Furthermore, they are easy to analyze by means of the polymerase chain reaction, using flanking unique sequence primers. In order to establish the utility of SSR markers for genetic mapping and for the analysis of corn germplasm, corn genomic libraries were constructed and screened for clones containing dinucleotide and trinucleotide repeats. One hundred and fifty clones were isolated and 34 of them were used in this study to analyze 15 (AG)n repeats, 15 (AC)n repeats, and 4 trinucleotide repeats. Twelve corn inbred lines, representing 87% of the RFLP alleles present in a collection of public corn cultivars, were used to assess the information content of the SSR markers. The expected heterozygosity of each SSR marker was compared with the expected heterozygosity of 100 different RFLP markers. The stability of SSRs was also tested through segregation analysis on an existing mapping population.
简单序列重复（SSRs）是一类相对较新的DNA标记，由短串联重复序列基序组成，这些基序均匀分布于整个真核生物基因组中。由于重复单元数量的变化率很高，SSRs显示出的多态性水平也很高。此外，利用侧翼独特序列引物，通过聚合酶链反应很容易对它们进行分析。为了确定SSRs标记在遗传图谱构建和玉米种质分析中的效用，构建了玉米基因组文库，并筛选含有二核苷酸和三核苷酸重复序列的克隆。分离出150个克隆，其中34个用于本研究，以分析15个（AG）n重复序列、15个（AC）n重复序列和4个三核苷酸重复序列。代表公共玉米品种集合中87%的RFLP等位基因的12个玉米自交系用于评估SSRs标记的信息含量。将每个SSRs标记的预期杂合度与100个不同RFLP标记的预期杂合度进行比较。还通过对现有作图群体的分离分析来测试SSRs的稳定性。
