一个水稻重复序列的分析与定位

Analysis and Mapping of a Rice Repeated Sequence

在利用PCR简并引物扩增水稻NBS LRR类抗病基因同源序列的研究中,克隆了一个大小为560bp左右的重复序列,命名为DH17。序列分析和同源性比较发现,该序列包含352bp的重复单位,与已报道的OS48和TrsA等重复单位序列进行比较,差异多低于5%,具有很高的同源性,因此为同一重复序列家族。分子杂交表明,该序列在籼型品种"窄叶青8号"(ZYQ8)中以大量的串联拷贝存在,拷贝数显著高于粳型品种"京系17"(JX17)。利用ZYQ8和JX17组配的DH群体,通过RFLP分析,直接将DH17的大量串联拷贝定位于ZYQ8的12号染色体长臂末端区域。

A repeated sequence with a length of 560 bp,termed as DH17,was obtained during PCR amplification of rice NBS-LRR homologues.A repeated unit of 352 bp in the DH17 fragment was revealed through sequence analysis and comparison,which has a high homology with the known sequences of OS48 and TrsA,and belongs to the same repeat family.Southern hybridization displayed that there are higher DH17 copies in the genome of an indica variety,ZYQ8,than that in the genome of japonica variety,JX17.The tandom repeated DH17 sequence was mapped on the long arm end of chromosome 12 through RFLP analysis of a double haploid population derived from ZYQ8 and JX17 using DH17 as a probe.