The transgene vector was constructed to contain an aspartic acid to alanine amino acid residue change at position 100 making the gene product insensitive to serotonin. It is under the control of a TetO promoter. Three lines were established and designated as B (or 2), C, and G (or 7). This transgene was originally designated as line B (or 2). This line shows slightly less expression than line G.