木薯地毯草黄单胞菌转化子T-DNA插入模式分析

T-DNA Insertion Patterns for the Genome of Xanthomonas axonopodis pv. manihotis Transformants

随机挑取30个已构建的木薯地毯草黄单胞菌（Xanthomonas axonopodis pv.manihotis）Tn5转化子,利用hi Tail-PCR技术获得Tn5转座子插入位点的侧翼序列64条。其中,有19个转化子获得了插入位点左右两端的侧翼序列,11个转化子获得了单侧侧翼序列。序列分析结果发现,插入位点集中在低GC含量区,特别是49%～50%的区域;Tn5转座子倾向于插入基因编码区内;Tn5转座子的插入会形成9 bp正向重复序列,且插入方向没有偏好性,9 bp正向重复序列的上下游碱基位点中,-5,-2,1,4,5,6,9,11位可能对转座酶的识别起关键作用。

Using high-efficiency thermal asymmetric interlaced PCR（ hi TAIL-PCR）,64 specific fragments of Xanthomonas axonopodis pv. Manihotis（ Xam） genomic DNA flanked on the T-DNA were successfully amplified from 30 randomly-picked Xam transformants. Nineteen transformants had fragments flanked on both borders of TDNA,and 11 contained fragments flanked on the left border of T-DNA. Analysis showed that the insertion sites were mainly found in the area with low GC content,especially the area with the GC content ranging between49%-50%; Tn5 transposon tended to be inserted into coding region; Tn5 transposon insertion formed a 9 bp direct repetitive sequence and had no preference in orientation. Among the upstream and downstream of the 9 bp direct repetitive sequence,the sites of-5,-2,1,4,5,6,9 and 11 might play a key role in the transposase recognition.