玉米基因枪法把五个不同基因共转移的研究

采用基因枪法把五个不同基因p35sGFP、pA ctG us、pU b iLuc、p35sPatP IV 4、pAH 2转移到玉米幼胚愈伤组织,以研究基因共转移的某些特性。试验结果表明,在处理B 1、B 2、B 3和B 4中,共获得转基因再生植株34株,分别涉及73、46、80和109个玉米幼胚愈伤组织,其基因转移频率分别是30.14%、17.39%、1.25%和2.75%。在基因转移中,一个幼胚愈伤组织一般可以获得一株转基因植株,同时也存在一个幼胚愈伤组织可以获得3株或以上的转基因植株的可能性。此外,有70%的机率能把3~4个不同基因进行至少一次克隆后共转移整合到玉米转基因再生植株上,而把五个不同基因共转移整合到玉米转基因再生植株上的机率则很低。不同基因的大小和质量会影响克隆的频率。已经整合到玉米转基因再生植株基因组上的转移基因的表达频率达到50%以上,不表达的转移基因则可能是基因沉默现象。

Co-transformation of five different genes on maize by particle bombardment

In order to study some properties of co-transformation,five different genes were introduced into embryogenic calluses of maize by particle bombardment.The DNAs used for co-transformation were p35sGFP and pActGus(two types of scorable mark gene),pUbiLuc(luciferase enzyme reporter gene),p35sPatPIV4(a selectable herbicide-resistance gene) and pAH2.Total 34 surviving independent transplants were obtained from B1,B2,B3 and B4 involving 73,46,80 and 109 bombarded embryos.The frequencies of B1,B2,B3 and B4 were 30.14%,17.39%,1.25% and 2.75%,respectively.One transplant generally was obtained from one event of bombarded embryo.The possibility was that more than three transplants might be obtained from the same event of bombarded embryo.There was 70% chance that three and four genes could be integrated into the genomes of the transformants for at least one copy.The chance of all five genes integrated into the genomes of the transformants was very low.The size of the transgenes and the quality of the DNAs might affect the clone frequency.The expression frequency of transgenes integrated to the genomic DNA of maize plants reached more than 50%.The non-expressional transgenes integrated to the genomic DNA might have the presence of gene silence phenomena in the transformants obtained in this study.