Tomita M, Kuramochi M, Iwata S
Molecular Genetics Laboratory, Faculty of Agriculture, Tottori University, Tottori, Japan.
Cytogenet Genome Res. 2009;125(4):306-20. doi: 10.1159/000235937. Epub 2009 Oct 27.
A new class of rye-specific repetitive DNA elements designated Superior has been identified. The rye genome library was constructed by cleavage with EcoO109I, the recognition sites of which consisted of 5'-PuGGNCCPy-3' multi-sequences and were present with high frequency in the rye repetitive families. A novel 495-bp segment enriched in the rye genome was successfully identified. Southern blot hybridization and fluorescence in situ hybridization using the repetitive element showed a dispersed array through all 7 chromosomes of rye. The repetitive DNA element did not share identity with known class I or class II transposable elements or known repetitive elements. Only several DNA segments in BACs and ESTs of barley showed partial similarity to the repetitive DNA element in all DNA databases of living species. The new class of dispersed repetitive elements was designated Superior. The entire structure of Superior was determined by using a rye genomic library of lambda FIXII screened by the 495-bp probe. The Superior family consisted of 1,292-bp, 1,324-bp, and 1,432-bp elements in which the 5' regions had been destroyed, indicating the presence of considerable structural diversity. Superior might be a useful tool for studying genomic organization and differentiation.
已鉴定出一类新的黑麦特异性重复DNA元件，命名为“Superior”。黑麦基因组文库是通过用EcoO109I酶切构建的，其识别位点由5'-PuGGNCCPy-3'多序列组成，并且在黑麦重复家族中高频出现。成功鉴定出一个在黑麦基因组中富集的495bp新片段。使用该重复元件进行的Southern印迹杂交和荧光原位杂交显示，其在黑麦的所有7条染色体上呈分散排列。该重复DNA元件与已知的I类或II类转座元件或已知的重复元件没有同源性。在所有生物物种的DNA数据库中，大麦BAC和EST中的几个DNA片段仅与该重复DNA元件显示出部分相似性。这种新的分散重复元件类别被命名为“Superior”。通过用495bp探针筛选lambda FIXII黑麦基因组文库，确定了“Superior”的完整结构。“Superior”家族由1292bp、1324bp和1432bp的元件组成，其中5'区域已被破坏，表明存在相当大的结构多样性。“Superior”可能是研究基因组组织和分化的有用工具。
