以转基因白桦(Betula platyphylla)为材料, 采用单酶切结合Southern杂交的方法揭示不同转基因植株中GUS基因的整合拷贝数为1-4个。采用组织化学染色法定性分析不同整合方式转基因白桦植株中GUS基因的表达。结果表明, 11个转基因植株中有2株出现了GUS基因沉默, 其余植株均有不同水平的GUS表达。在此基础上应用分光光度法定量分析不同拷贝数的GUS转基因白桦中b-葡萄糖醛酸酶活性。结果表明, 在11个转基因无性系中除2个株系的GUS基因沉默外, 其它9个转基因植株中GUS酶活力差异明显, 但这种差异与GUS基因的拷贝数没有必然联系。

To determine the copy number of the transgene, the single- restriction enzyme Pst I was used to digest the genomic DNA. Southern blot analys is of transgenic birch plants indicated that the GUS gene had been integrated into the birch genome. Among the 11 transgenic birch lines, the copy number of GUS varied from1 to 4. The expression of the GUS gene w as studied by his tochemic al staining and spectrophotometry . His tochemical staining with X-gluc showed the GUS gene silenced in TP30 and TP96 plants , and that significant dif ferences of GUS activity was observed in other transgenic plants, with GUS activity remarkably high in TP23, TP36 and TP71 plants. However, the copy number and expression of the GUS gene were not significantly related.