水稻第4号染色体不同位置的Ds转座子转座行为的分析

使用农杆菌介导的方法转化粳稻品种中花11，构建了在第4号染色体不同位置插入了Ds（dissociation）因子的水稻转化群体和带有Ac（activator）转座酶基因的转化植株。将携带了Ac转座酶基因的植株与不同Ds转化植株杂交，杂交F1代同时带有Ac转座酶和Ds因子（Ac／Ds植株）。用PCR方法检测了杂交F1代Ds的切离频率，结果发现靠近第4号染色体着丝粒附近的Ds转座子切离频率低，而靠近第4号染色体末端区域的Ds转座子切离频率高，这表明Ds转座子的原始插入位置对其杂交后代的切离频率有很大的影响，推测与原始插入位点附近的染色体结构有关。

Transpositional Behaviour Analysis of Ds Element from Different Insertion Sites on Chromosome 4 in Rice

Transgenic plants with Ds element dis- tributed over different loci on chromosome 4 (Fig. 1) and the homozygous transformants with Ac transposase gene were established through Agrobacterium-mediated approach. In this study, the plants carrying Ds element from different loci were crossed with the plant carrying Ac transposase individually. The plants of F1 generation carrying both Ds element and Ac transposase were used to produce the F2 populations (Table 1). Analysis of the F2 generation by the PCR method revealed that the excision frequencies of Ds element were higher in the telomeric region of chromosome 4 than inthe centromeric region (Fig.4). These results showed that the insertion site of Ds element has strong effect on its excision frequency. We sug- gest that the special construct of chromosome near the insertion site of Ds element is related to the excision frequency of the Ds element.