Drosophila male courtship behavior is modulated by ecdysteroids

Abstract

Temperature-dependent induction of ecdysteroid deficiency in the ecdysoneless mutant ecd1 adult Drosophila melanogaster results in altered courtship behavior in males. Ecdysteroid deficiency brings about significantly elevated male-male courtship behavior including song production resembling that directed towards females. Supplementation with dietary 20-hydroxyecdysone reduces male-male attraction, but does not change motor activity, courtship patterns or attraction to females. These observations support the hypothesis that reduced levels of ecdysteroids increase the probability that male fruit flies will display courtship behaviors to male stimuli.

Drosophila female precopulatory behavior is modulated by ecdysteroids

“…If full ovipositor extrusion indicates unwillingness to copulate, then perhaps reduction of this behavior is related to an increase in sexual motivation and receptivity. A comparable increase in sexual motivation is evident in previous studies of the ecdysoneless 1 male, which shows an elevated courtship level in the presence of both male and female targets (Ganter et al, 2011). In this way, the evidence supports the hypothesis that in both sexes, ecdysteroid deficiency positively affects sexual motivation.…”

“…In previous studies, when ecdysteroid signaling levels were reduced in male EcR mutants (Ganter et al, 2007; Dalton et al, 2009) or male ecdysoneless 1 mutants (Ganter et al, 2011), male flies showed significantly elevated male-male attraction including all typical elements of female-directed courtship except copulation. This suggests that in male fruit flies, ecdysteroid signaling modulates courtship behavior.…”

“…Perhaps ecdysteroids achieve such control by interacting with the sex determination hierarchy or by influencing the excitability of certain subsets of the neurons involved in controlling sexual behavior. Reduction of ecdysteroid signaling levels in females, or males (Ganter et al, 2011), does not alter behavioral patterns involved in courtship but rather alters the initiation of those patterns in response to courtship target-derived olfactory, gustatory and visual stimuli (Koganezawa et al, 2010; Pan et al, 2011). This result joins the growing body of evidence suggesting that ecdysteroids have a role in regulating adult behavioral processes, for example, in memory and in sleep (Ishimoto et al, 2009; Ishimoto and Kitamoto, 2010).…”

“…Males deficient in either ecdysteroid level (Ganter et al, 2011) or the nuclear ecdysone receptor (EcR) (Ganter et al, 2007, Dalton et al, 2009) show elevated levels of male-male courtship. Derived from cholesterol mainly in the larval prothoracic gland, the ecdysteroids, especially 20-hydroxyecdysone, together with EcR comprise an essential developmental signal pathway (Riddiford, 1993).…”

Accessory Gland as a Site for Prothoracicotropic Hormone Controlled Ecdysone Synthesis in Adult Male Insects

“…A recent study also shows that conditional reduction of ecdysteroid signaling in the adult stage, and not during development, causes the males to display male-male courtship [52], indicating that the effects of ecdysteroids is not solely explained by neuronal wiring of a male-specific circuitry during development. This phenotype is also observed in males that lack PTTH [29], suggesting that PTTH may regulate E production in adults.…”