Detection of the T - DNA in Chromosome a of Haplopappus gracilis by in Situ Hybridization

다국어 초록 (Multilingual Abstract)

The T-DNA of the pTi plasmid of Agrobacterium tumefaciens has been analyzed by in situ hybridization and Southern analysis in cloned transformed plant cell lines of Haplopappus gracilis, a plant with two distinctive chromosomes. Southern analyses performed on these tumor cell lines indicated that transformation in plants of H. gracilis by A. tumefaciens strain C58 can result in T-DNA integration at different positions within the plant genome, and of varying size and copy number. A cell line with one full length copy of T-DNA was selected for in situ hybridization analysis. Protoplasts isolated in metaphase provided relatively planar target chromosomes free of interfering cell walls. In situ hybridization analysis has mapped this T-DNA insertion to a region near the centromere in the long arm of chromosome A of H. gracilis. Similarly (using the ribosomal RNA genes of wheat as probe) the position of ribosomal RNA genes of H. gracilis have been mapped by in situ hybridization to a position near the subterminal centromere of chromosome B.