Unsaturated, long-
chain hydrocarbons are found on the cuticles of insects and can act as pheromones. In mature
Drosophila melanogaster, certain cuticular hydrocarbons are sexually dimorphic: males synthesize 23-
and 25-
C monoenes and females produce 27-
and 29-
C dienes. Each of these lipids plays specific roles in regulating male sexual behavior, with dienes stimulating courtship.
1 7(Z),11(Z)-
Pentacosadiene is a 25-
C hydrocarbon that is found in low abundance on cuticles of mature
Drosophila females.
2 Depletion of a female-
specific elongase (eloF), which leads to an increase in 7(Z),11(Z)-
pentacosadiene along with a parallel decrease in 7,11-
nonacosadiene, significantly reduces copulation in
Drosophila.
3 This raises the possibility that 7(Z),11(Z)-
pentacosadiene may act as an anti-
aphrodisiac.