Hierarchical Control of Drosophila Sleep, Courtship, and Feeding Behaviors by Male-Specific P1 Neurons

Animals choose among sleep, courtship, and feeding behaviors based on the integration of both external sensory cues and internal states; such choices are essential for survival and reproduction. These competing behaviors are closely related and controlled by distinct neural circuits, but whether they are also regulated by shared neural nodes is unclear. Here, we investigated how a set of male-specific P1 neurons controls sleep, courtship, and feeding behaviors in Drosophila males. We found that mild activation of P1 neurons was sufficient to affect sleep, but not courtship or feeding, while stronger activation of P1 neurons labeled by four out of five independent drivers induced courtship, but only the driver that targeted the largest number of P1 neurons affected feeding. These results reveal a common neural node that affects sleep,courtship, and feeding in a threshold-dependent manner,and provide insights into how competing behaviors can be regulated by a shared neural node.

Sex and Death:Identification of Feedback Neuromodulation Balancing Reproduction and Survival

Some semelparous organisms in nature mate as many times as they can in a single reproductive episode before death,while most iteroparous species including humans avoid such suicidal reproductive behavior.Animals naturally pursue more sex and the possible fatal consequence of excessive sex must be orchestrated by negative feedback signals in iteroparous species,yet very little is known about the regulatory mechanisms.Here we used Drosophila male sexual behavior as a model system to study how excessive sex may kill males and how the nervous system reacts to prevent death by sex.We found that continuous sexual activity by activating the fruitlessexpressing neurons induced a fixed multi-step behavioral pattern ending with male death.We further found negative feedback in the fly brain to prevent suicidal sexual behavior by expression changes of the neurotransmitters acetylcholine and gamma-aminobutyric acid,and neuropeptide F.These findings are crucial to understand the molecular underpinnings of how different organisms choose reproductive strategies and balance reproduction and survival.

The sex determination gene doublesex regulates expression and secretion of the basement membrane protein Collagen Ⅳ

The highly conserved doublesex(dsx) and doublesex/mab-3 related(Dmrt) genes control sexually dimorphic traits across animals. The dsx gene encodes sex-specific transcription factors, Dsx^(M) in males and Dsx^(F) in females, which function differentially and often oppositely to establish sexual dimorphism. Here, we report that mutations in dsx, or overexpression of dsx, result in abnormal distribution of the basement membrane(BM) protein Collagen Ⅳ in the fat body. We find that Dsx isoforms regulate the expression of Collagen Ⅳ in the fat body and its secretion into the BM of other tissues. We identify the procollagen lysyl hydroxylase(dPlod) gene, which is involved in the biosynthesis of Collagen Ⅳ, as a direct target of Dsx. We further show that Dsx regulates Collagen Ⅳ through d Plod-dependent and independent pathways. These findings reveal how Dsx isoforms function in the secretory fat body to regulate Collagen Ⅳ and remotely establish sexual dimorphism.

The sex determination gene doublesex is required during adulthood to maintain sexual orientation

Gender differences in behavior are prevalent among animal kingdoms. The causal links among a particular gene, neural circuitry, and gendered behaviors have long been of particular interest in neuroscience. The fruit fly, Drosophila melanogaster, is a wonderful animal model with fruitful genetic tools to tackle these questions(Guo et al., 2019). It has been found that two sex determination genes,fruitless(fru) and doublesex(dsx), jointly govern the sex differences in the nervous system that regulate the male-specific courtship behavior(Burtis and Baker, 1989;Ito et al., 1996;Ryner et al.