The mutation present in ry609 (nucleotide substitution G3506A) has been introduced by site-directed mutagenesis. The following additional nucleotide substitutions have also introduced by site-directed mutagenesis: G-2914C (destroys a PstI site), C1103G and C1106T (these two changes together destroy a PstI site), A2950G (destroys a BamHI site), C3358G (destroys a SphI site), A3511T (creates a BglI site together with the ry609 G3506A mutation), C3610A (creates an EcoRI site), A3735C (creates a BamHI site), insertion of GATATCGAATT at +4163 (inserts EcoRV and EcoRI sites), C4169G (destroys a NheI site) and C6998G (destroys an AgeI site). (Coordinates follow the system of FBrf0044473, in which +1 is within an EcoRI site in the second exon. This corresponds to nucleotide 3R:8859890 on the release 5 genome.)