RESUMEN
Ac and Ds insertions among the genomic DNAs of hybrids of Ac x Ds lines were screened by PCR. The genomic DNAs, which were proved to harbour both Ac and Ds, were used as templates in TAIL-PCR to clone the Ds flanking sequences. The cloned specific fragments were sequenced, and the sequenced Ds flanking sequences were used as query sequences to perform on-line sequence comparing analysis against GenBank by employing BLAST program of NCBI. The information about the chromosome location of Ds-inserted genes, or genes immediately downstream of the inserted sites, and their functional innotations were achieved. Based on the analysis from the cloned 93 Ds-flanking sequences, it was found that 21 hybrid plants had Ds insertions in genic regions, whereas the remaining 72 samples's intergenic regions were inserted by Ds element. Moreover, among the 72 regions, 12 were inserted immediately upstream (within 3 kb) of specific genes. Also, the strategies to improve the performance in cloning the Ds flanking sequences and in screening the Ac/Ds lines were emphasized.
