Rapid, large-scale generation of Ds transposant lines and analysis of the Ds insertion sites in rice

• Published in: The Plant journal : for cell and molecular biology Vol. 39; no. 2; pp. 252 - 263
• Main Authors: Kim, C.M, Piao, H.L, Park, S.J, Chon, N.S, Je, B.I, Sun, B, Park, S.H, Park, J.Y, Lee, E.J, Kim, M.J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.07.2004; Blackwell Science
• Subjects: Biological and medical sciences; Chromosome Mapping; Crosses, Genetic; Culture Techniques; Diverse techniques; DNA Transposable Elements; DNA, Bacterial - genetics; DNA, Plant - genetics; Fundamental and applied biological sciences. Psychology; Gene Transfer Techniques; Genetic Vectors; Genome, Plant; grain crops; in vitro regeneration; insertional mutagenesis; mapping; micropropagation; Models, Genetic; Molecular and cellular biology; Mutagenesis, Insertional; Oryza - genetics; Oryza sativa; Promoter Regions, Genetic; Regeneration; rice; Seeds - genetics; Seeds - growth & development; Transformation, Genetic; transgenic plants; transposons; Genetic mapping; insertional mutagenesis; Monocotyledones; Ac; mapping; Tissue culture; Transposable element; Experimental protocol; rice; Ds; Oryza sativa; Regeneration; Gramineae; Insertion mutation; Angiospermae; Production; Spermatophyta
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2004.02116.x

Rapid, large-scale generation of a Ds transposant population was achieved using a regeneration procedure involving tissue culture of seed-derived calli carrying Ac and inactive Ds elements. In the F2 progeny from genetic crosses between the same Ds and Ac starter lines, most of the crosses produced an independent germinal transposition frequency of 10-20%. Also, many Ds elements underwent immobilization even though Ac was expressed. By comparison, in a callus-derived regenerated population, over 70% of plants carried independent Ds insertions, indicating transposition early in callus formation. In the remaining population, the majority of plants carried only Ac. Most of the new Ds insertions were stably transmitted to a subsequent generation. An exceptionally high proportion of independent transposants in the regenerated population means that selection markers for transposed Ds and continual monitoring of Ac/Ds activities may not necessarily be required. By analyzing 1297 Ds-flanking DNA sequences, a genetic map of 1072 Ds insertion sites was developed. The map showed that Ds elements were transposed onto all of the rice chromosomes, with preference not only near donor sites (36%) but also on certain physically unlinked arms. Populations from both genetic crossing and tissue culture showed the same distribution patterns of Ds insertion sites. The information of these mapped Ds insertion sites was deposited in GenBank. Among them, 55% of Ds elements were on predicted open-reading frame (ORF) regions. Thus, we propose an optimal strategy for the rapid generation of a large population of Ds transposants in rice.