Meyer P, Heidmann I, Niedenhof I
Max-Delbrück-Laboratorium in der MPG, Cologne, F.R.G.
Gene. 1992 Jan 15;110(2):213-7. doi: 10.1016/0378-1119(92)90650-e.
This paper describes the development of a gene-displacement vector based on DNA1, one of two single stranded circular genomic components of a bipartite geminivirus, African cassava mosaic virus (ACMV). The DNA1 molecules of ACMV were cloned as dimers into a plant transformation vector and the constructs have been integrated into tobacco protoplasts by PEG-mediated DNA transfer. In transgenic plants extrachromosomal copies of DNA1 monomers could be detected. Deletion of the coat protein-encoding gene in chimeric constructs resulted in free DNA1 copies of reduced size, and extrachromosomal recombinant molecules were detected after displacement of the coat protein-encoding region by foreign DNA fragments of comparable size. Due to the absence of the second component of ACMV, DNA2, the transgenic plants are free from viral infection symptoms which allows the establishment of healthy transformants that carry a recombinant construct in an extrachromosomal form.
本文描述了一种基于DNA1构建的基因置换载体的开发过程，DNA1是双生病毒非洲木薯花叶病毒（ACMV）的两个单链环状基因组组件之一。ACMV的DNA1分子以二聚体形式克隆到植物转化载体中，构建体通过聚乙二醇（PEG）介导的DNA转移整合到烟草原生质体中。在转基因植物中可以检测到DNA1单体的染色体外拷贝。嵌合构建体中衣壳蛋白编码基因的缺失导致游离的DNA1拷贝大小减小，并且在衣壳蛋白编码区被大小相当的外源DNA片段置换后检测到染色体外重组分子。由于缺少ACMV的第二个组件DNA2，转基因植物没有病毒感染症状，这使得能够建立以染色体外形式携带重组构建体的健康转化体。
