P{GawB} insertion in the intron between hts exons 1 and 2. Expression of the hts-RD and hts-RP transcripts is significantly reduced in mutant males compared to controls (q-PCR analysis of RNA extracted from isolated male heads); no significant reduction in expression of the Add1/HtsM or Add2 isoforms is seen. Expression of the neighboring CalpA gene is also mildly, but significantly reduced in the mutant males (q-PCR analysis of RNA extracted from isolated male heads).

Rescue experiments demonstrate that the hyperaggressive phenotype seen in P{GawB}hts^sxp males under social isolation conditions is due to the effect of the insertion on hts expression (and is not due to its effect on CalpA expression), as the phenotype is rescued by a transgene that encompasses hts but does not encode the complete coding sequence CalpA.