The w+* marker in TI{TI}Gr68aΔ1 has been replaced with the endogenous Gr68a sequence.
Gr68aRes1 mutant flies do not exhibit reduced sensitivity to (S,Z,Z)-CH503 (a more potent stereoisomer of the gustatory sex pheromone CH503). As in wild type, courtship defects are seen in these flies in response to (S,Z,Z)-CH503.