玉米简单重复序列不对等交换的热点区域定位

Mapping Unequal Crossing over Hotspot Region of Simple Sequence Repeat in Maize

生物基因组中简单重复序列的多态性是同源染色体不对等交换的结果之一,因此明确不对等交换的热点区域具有重要的理论意义。利用来源于优良玉米杂交种豫玉22的一套重组近交系(RIL)群体,对其遗传组成进行了SSR标记分析,发现40个不对等交换的SSR标记,不对等交换在群体间发生的概率介于0.34%～14.63%之间,每世代发生的频率为10-2～10-1,其中(AG)n重复的标记占发生不对等交换总标记的58.3%。有31个不对等交换标记分布于染色体上的11个热点区域,位于第9染色体以外的其他染色体上,其中第3和第5染色体上各分布2个不对等交换的热点区域。

The polymorphism of simple sequence repeat （SSR） in biological genome is one result of unequal crossing over for homologous chromosomes; therefore it has theoretical importance in clarifying the hotspot regions of unequal crossing over. A set of recombinant inbred lines （RILs） population that derived form an elite hybrid Yuyu 22 was used in this study, its genetic components of the population was analyzed by means of SSR analysis, and 40 unequal crossing over SSR markers were found. The frequency of the unequal crossing over in the RIL population was 0.34-14.63%, with 10^-2-10^-1 frequency per generation, and the （AG）n repeat SSR markers accounted for 58.3%. There were 31 unequal crossing over markers locating on 11 chromosomal hotspot regions, distributing on 10 chromosomes except for chromosome 9, including two unequal crossing over hotspot regions each in chromosomes 3 and 5.