Agrobacterium을 이용하여 형질전환시킨 배추에서 T-DNA Right Border 인접염기서열 분석

Analysis of right border flanking sequence in transgenic chinese cabbage harboring integrated T-DNA

We developed 14 transgenic lines of Chinese cabbage Brassica rapa harboring the T-DNA border sequences and CryIAc1 transgene of the binary vector 416 using Agrobacterium tumefaciens-mediated DNA transfer. Six lines had single copy cryIAc1 gene and four of them contained no vector backbone DNA. Of the left border (LB) flanking sequences six nucleotides were deleted in transgenic lines 416-2 and 416-3, eleven nucleotides in line 416-9, and 65 nucleotides including the whole LB sequences in line 416-17, respectively. And we defined 499 bp of genomic DNA (gDNA) of transformed Chinese cabbage, and blast results showed 96% homology with Brassica oleracea sequences. PCR with specific primer for the right border (RB) franking sequence revealed 834 bp of PCR product sequence, and it was consisted of 3` end of cryIAc1, nosterminal region and 52 bp of Chinese cabbage genomic DNA near RB. RB sequences were not found and the 58 nucleotides including 21 bp of nos-terminator 3` end were deleted. Also, there were deletion of 10 bp of the known genomic sequences and insertion of 65 bp undefined genomic sequences of Chinese cabbage in the integration site. These results demonstrate that the integration of T-DNA can be accompanied by unusual deletions and insertions both in transgenic and genomic sequences.