Patent ID: 7498481

Claim:
A method for obtaining a transgenic maize plant containing a coding sequence of interest that is free of ancillary selection marker sequence comprising: (a) transforming a maize plant, or a cell of a maize plant, that lacks an active Ac element transposase, with a transformation vector comprising: (1) a first expression cassette comprising a coding sequence of interest that is not bordered by mobilizable sequences of a maize active Ac element transposon; and (2) a second expression cassette comprising a nucleotide sequence encoding an ancillary selection marker that is bordered by the mobilizable sequences of a maize active Ac element transposon, wherein said nucleotide sequence encoding the ancillary selection marker is operably linked to a plant expression control sequence, to obtain primary transformants; (b) growing the primary transformants under selective conditions to obtain at least one transformed parental maize plant having the ancillary selection marker coding sequence; (c) producing an F1 generation by crossing the selected transformed parental maize plant with a second parental maize plant, said second maize plant having within its genome a sequence encoding an endogenous active Ac element transposase that operates on the mobilizable sequences of the second expression cassette, wherein said sequence encoding the endogenous active transposase encodes the active Ac element within an R-nj::AC allele of the R-nj chromosomal locus such that excision of the said Ac element results in the production of anthocyanin-containing sectors on the crown of the seed, including the embryo; (d) selecting a maize plant from the F1 generation having said anthocyanin-containing sectors; and (e) regenerating a maize plant from the plant, or a cell of the maize plant, selected in (d), such that a transgenic maize plant containing a coding sequence of interest that is free of ancillary selection marker sequence is produced.