The cacophony Gene and Repetitive-pattern Phenotypes in Drosophila melanogaster

The cacophony (cac) gene is located on the X-chromosome of Drosophila and codes for the a-1(pore-forming) subunit of a voltage-gated calcium channel. Certain mutations in this gene result in both an aberrant courtship song and a heartbeat with rate and rhythmicity significantly different from wild-type. The cacS mutants produce songs with polycyclic pulses, increased inter-pulse intervals and enhance pulse amplitudes compared with the songs of wild-type males. Given the repetitive patterns of output that define both courtship song and heartbeat in the cac mutant, the cac gene is a likely candidate for regulating or forming core oscillator components of such behaviors. To establish definitively the molecular etiology of these defects, it must be determined where in the body of the fiuit fly the cac gene is expressed. Using imrnunohistochemistry coupled with the GAUIUAS system, I attempted to assess the anatomical location of cac expression. Also, by driving the expression of wild- type cac in the cacS or cac-lethal background, I hoped to rescue the courtship song phenotype. However, the UAS-cacf construct turned out to be leaky, affecting the outcome of both experiments. While the pan-neuronal and pan-muscular drivers combined with the UAS-C~C+ transgene did alter the song phenotype of the cacS and cac- lethal background flies, the phenotype was not fully rescued. In parallel, whole mount preparations of the fly heart and CNS, and CNS cryostat sections showed punctate anti- cac staining, but controls are needed to verify the effectiveness of the antibody