Somatic mobility of the maize element Ac and its utility for gene tagging in aspen.
We have investigated the somatic activity of the maize Activator (Ac) element in aspen with the objective of developing an efficient transposon-based system for gene isolation in a model tree species. The analysis of the new insertion sites revealed the exact reconstitution of the Ac, however, aberrant transposition events were also found. Characterization of the genomic sequences flanking the Ac insertions showed that about one third (22/75) of the sequences were significantly similar to sequences represented in public databases and might correspond to genes. The frequency of Ac landing into coding regions was about two-fold higher when compared to the frequency of T-DNA hitting the predicted genes (5/32) in the aspen genome. Thus, Ac is demonstrated to be a potentially useful heterologous transposon tag in a tree species. This is the first report on transposon-based gene tagging in a tree species describing the excision and reinsertion of transposable element into new genomic positions. We also suggest a heterologous transposon tagging strategy that can be used in aspen somatic cells to obtain dominant gain-of-function mutants and recessive loss-of-function mutants overcoming the regeneration time barrier of a long-lived tree species.
Kumar
Sandeep
S
BFH Institute for Forest Genetics and Forest Tree Breeding, Sieker Land Str. 2, D-22927 Grosshansdorf, Germany. kumar@holz.uni-hamburg.de
Fladung
Matthias
M
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics*; D030561:Databases, Nucleic Acid; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000235:genetics*; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D003313:Zea mays / Q000235:genetics*
D004251:DNA Transposable Elements