Zhang X Y, Dong Y S, LI P, Wang R R
Institute of Crop Germplasm Resources, Chinese Academy of Agricultural Sciences, Beijing.
Yi Chuan Xue Bao. 1998 Apr;25(2):131-41.
Two E genome--(including Ee and Eb) and two St-genome-specific RAPD markers were successfully cloned. Sequencing data indicated that the four DNA fragments were reported for the first time. Chromosome fluorescent in situ hybridization (FISH) showed that OPD-12(444) (E-specific) was a highly tandem repeat. OPF-03(1296) (Eb-specific), OPB-08(525) (St-specific), and OPN-01(817) (St-specific) were highly dispersed repetitive sequences. The FISH and Southern hybridization of genomic DNA also revealed that all of the four highly repetitive sequences were shared among relatively closer genomes of triticeae. The difference was mainly in the fragment length and the copy number. Whether a genome can amplify a specific sequence via RAPD is mainly dependent on if there are primering sites at both ends of this sequence in the genome. We also discussed the potentiality of these highly repetitive DNA fragments in detection of alien chromatin in wheat and determination of genome constitution of polyploid triticeae species.
成功克隆了两个E基因组（包括Ee和Eb）特异的以及两个St基因组特异的RAPD标记。测序数据表明这四个DNA片段首次被报道。染色体荧光原位杂交（FISH）显示OPD-12(444)（E特异）是高度串联重复序列。OPF-03(1296)（Eb特异）、OPB-08(525)（St特异）和OPN-01(817)（St特异）是高度分散的重复序列。基因组DNA的FISH和Southern杂交还表明，这四个高度重复序列在小麦族亲缘关系较近的基因组中都有。差异主要在于片段长度和拷贝数。一个基因组能否通过RAPD扩增出特定序列主要取决于该序列两端在基因组中是否有引物结合位点。我们还讨论了这些高度重复DNA片段在检测小麦中外源染色质以及确定多倍体小麦族物种基因组构成方面的潜力。
