Nakajima R, Noma K, Ohtsubo H, Ohtsubo E
Institute of Molecular and Cellular Biosciences, University of Tokyo, Japan.
Genes Genet Syst. 1996 Dec;71(6):373-82. doi: 10.1266/ggs.71.373.
Three kinds of DNA sequences (here called TrsB, TrsC and RIRE1) have been previously reported to be those repeated in tandem specifically in the wild rice species with FF, CC or EE genome, respectively. To characterize these genome type-specific sequences, we carried out PCR using a pair of primers, which hybridize to a restricted region in the repeating unit sequence and prime DNA synthesis in both directions. Gel electrophoresis and DNA sequencing revealed that PCR using primers for TrsB (or TrsC) amplified the fragments with an integral series of a unit length not only from total DNA of the rice strain with FF (or CC) genome, but also from those of the rice strains with non-FF (or non-CC) genome. TrsB or TrsC was, however, found to be repeated in an extraordinary number of copies in the species with FF or CC genome, respectively, in which the TrsB (or TrsC) sequence has been originally identified. PCR using primers for RIRE1 produced various sizes of fragments from total DNA of the rice strains with EE genome. The fragments, however, showed no progression at interval of the unit length characteristic for tandem repeats. Nucleotide sequencing of the amplified fragments revealed that they were not the sequences repeated in tandem, but were those interspersed as an element having partial homology with the LTR sequences of retrotransposons, Wis-2-1A in wheat and BARE-1 in barley. RIRE1 was present in the rice species with any types of genomes, but in the species with EE genome in an extraordinary number of copies.
先前有报道称，三种DNA序列（这里称为TrsB、TrsC和RIRE1）分别在具有FF、CC或EE基因组的野生稻物种中特异性串联重复。为了表征这些基因组类型特异性序列，我们使用一对引物进行了PCR，这对引物与重复单元序列中的一个受限区域杂交，并在两个方向上引发DNA合成。凝胶电泳和DNA测序显示，使用TrsB（或TrsC）引物进行的PCR不仅从具有FF（或CC）基因组的水稻菌株的总DNA中扩增出了一系列单位长度整数倍的片段，而且还从具有非FF（或非CC）基因组的水稻菌株的总DNA中扩增出了这些片段。然而，发现TrsB或TrsC分别在最初鉴定出TrsB（或TrsC）序列的具有FF或CC基因组的物种中以极大量的拷贝数重复。使用RIRE1引物进行的PCR从具有EE基因组的水稻菌株的总DNA中产生了各种大小的片段。然而，这些片段在串联重复特征性的单位长度间隔处没有呈现出递进关系。对扩增片段的核苷酸测序表明，它们不是串联重复序列，而是作为一种与小麦中的Wis-2-1A和大麦中的BARE-1反转录转座子的LTR序列具有部分同源性的元件散布的序列。RIRE1存在于任何基因组类型的水稻物种中，但在具有EE基因组的物种中以极大量的拷贝数存在。
