“…For PCR analysis, the gus gene primer set, 5′-AA-TTGATCAGCGTTGGTGG-3′ and 5′-GGTGTAGAGCATTACG-CTGC-3′, which yields a 0.45-kbp fragment inside of the gus gene (Anzai et al 1996), or the hpt gene primer set, 5′-CCTGAA-CTCACCGCGACG-3′ and 5′-AAGACCAATGCGGAGC ATAT-AC-3′, which generates a 0.81-kbp fragment inside of the hpt gene (Cho et al 1997), were used. PCR amplification reactions contained 20 ng of template DNA, 0.4 µM of each primer, 100 µM of a dNTP mixture, 1× Taq DNA polymerase reaction buffer and 1 U Taq DNA polymerase (Takara, Japan) in a 20 µl final volume.…”