Deletion of 6 bases and insertion of 4 (TCTT) at the site of the deletion in the first exon of robo1-RA within the FROS sequence (Fru[BM] response oligatory sequence).
TCTT
During courtship, robo1Δ1/+ males show precocious wing switching (duration the mutant continues to use the same wing is much shorter, quantified as a significantly larger wing switching index) compared to controls.