Or47b Receptor Neurons Mediate Sociosexual Interactions in the Fruit Fly Drosophila melanogaster

Abstract

In the fruit fly Drosophila melanogaster, social interactions especially among heterosexual couples have been shown to have significant impact on the circadian timing system. Olfaction plays a major role in such interactions; however, we do not know yet specifically which receptor(s) are involved. Further, the role of circadian clock neurons in the rhythmic regulation of such sociosexual interactions (SSIs) is not fully understood. Here, we report the results of our study in which we assayed the locomotor activity and sleep-wake behaviors of male-male (MM), female-female (FF), and male-female (MF) couples from several wild-type and mutant strains of Drosophila with an aim to identify specific olfactory receptor(s) and circadian clock neurons involved in the rhythmic regulation of SSI. The results indicate that Or47b receptor neurons are necessary for SSI, as ablation or silencing of these neurons has a severe impact on SSI. Further, the neuropeptide pigment dispersing factor (PDF) and PDF-positive ventral lateral (LN(v)) clock neurons appear to be dispensable for the regulation of SSI; however, dorsal neurons may be involved.

Sexual Interactions Influence the Molecular Oscillations in DN1 Pacemaker Neurons in Drosophila melanogaster

“…Such nocturnality was not observed in male-male pairs or female-female pairs (Figure 1B, C). This observation is consistent with those of previous studies [16,29]. To determine whether the nocturnality in male-female pairs is mediated by the circadian clock, we paired male and female per 01 arrhythmic mutants, in which the circadian feedback loops stop due to the lack of a functional per gene [31].…”

“…Because we used a conventional activity recording system, the activity of each male and female fly was pooled, as in a previous study [29]. Individual flies displayed typical bimodal activity patterns with peaks in the morning and evening (Figure 1A, red and blue, respectively).…”

How Food Controls Aggression in Drosophila

“…Previous studies showed that Gr5a-GAL4 do not overlap with markers for pheromone-sensing GRNs (ppk23, ppk25, and fru M ) [10], [14], and that Gr5a + GRNs did not respond to male pheromones [20]. Furthermore, disruption of Gr5a + function does not decrease aggression when the aggression promoting resource is females instead of food (Figure S8a), nor does it produce any effect on courtship or social behaviors [18], [75]. Finally, disruption of Gr5a + GRNs function decreases aggression in the presence of sucrose (Figure S8c).…”

Transcriptional profiling of adult Drosophila antennae by high-throughput sequencing

“…Or47b and Or67d showed higher expression levels in male flies, while Or59b, Or9a, and Obp19b showed higher expression levels in female flies. Or47b and Or67d were proposed as being involved in sociosexual interactions in flies, such as courtship and mating behaviors (Lone and Sharma 2012). In particular, the ablation of Or47b neurons had the most dramatic effect on the sociosexual interaction behaviors (Lone and Sharma 2012).…”

“…Or47b and Or67d were proposed as being involved in sociosexual interactions in flies, such as courtship and mating behaviors (Lone and Sharma 2012). In particular, the ablation of Or47b neurons had the most dramatic effect on the sociosexual interaction behaviors (Lone and Sharma 2012). Using microarrays, Kopp et al (2008) found 406 differentially expressed genes between male and female antennae among 9,830 genes examined, including 20 Or and Obp genes (with a FDR of <0.2).…”