Heterogeneity in the projections and excitability of tyraminergic/octopaminergic neurons that innervate the reproductive tract.

Aminergic nuclei in mammals are generally composed of relatively small numbers of cells with broad projection patterns. Despite the gross similarity of many individual neurons, recent transcriptomic, anatomic and behavioral studies suggest previously unsuspected diversity. Smaller clusters of aminergic neurons in the model organism provide an opportunity to explore the ramifications of neuronal diversity at the level of individual cells.

Expression and potential regulatory functions of Drosophila octopamine receptors in the female reproductive tract.

Aminergic signaling is known to play a critical role in regulating female reproductive processes in both mammals and insects. In Drosophila, the ortholog of noradrenaline, octopamine, is required for ovulation as well as several other female reproductive processes. Two octopamine receptors have already been shown to be expressed in the Drosophila reproductive tract and to be required for egg-laying: OAMB and Octβ2R.

Precise CRISPR-Cas9-mediated mutation of a membrane trafficking domain in the vesicular monoamine transporter gene.

Monoamine neurotransmitters such as noradrenalin are released from both synaptic vesicles (SVs) and large dense-core vesicles (LDCVs), the latter mediating extrasynaptic signaling. The contribution of synaptic versus extrasynaptic signaling to circuit function and behavior remains poorly understood. To address this question, we have previously used transgenes encoding a mutation in the Vesicular Monoamine Transporter () that shifts amine release from SVs to LDCVs.

cells that express octopamine receptors can either inhibit or promote oviposition.

Adrenergic signaling is known to play a critical role in regulating female reproductive processes in both mammals and insects. In , the ortholog of noradrenaline, octopamine (Oa), is required for ovulation as well as several other female reproductive processes. Loss of function studies using mutant alleles of receptors, transporters, and biosynthetic enzymes for Oa have led to a model in which disruption of octopaminergic pathways reduces egg laying.

Regulation of oviduct muscle contractility by octopamine.

Octopamine is essential for egg-laying in , but the neuronal pathways and receptors by which it regulates visceral muscles in the reproductive tract are not known. We find that the two octopamine receptors that have been previously implicated in egg-laying- and -are expressed in octopaminergic and glutamatergic neurons that project to the reproductive tract, peripheral ppk(+) neurons within the reproductive tract and epithelial cells that line the lumen of the oviducts. Further optogenetic and mutational analyses indicate that octopamine regulates both oviduct contraction and relaxation via and respectively.

Vesicular neurotransmitter transporters in Drosophila melanogaster.

Drosophila melanogaster express vesicular transporters for the storage of neurotransmitters acetylcholine, biogenic amines, GABA, and glutamate. The large array of powerful molecular-genetic tools available in Drosophila enhances the use of this model organism for studying transporter function and regulation.

Ecdysis triggering hormone receptors regulate male courtship behavior via antennal lobe interneurons in Drosophila.

Ecdysis triggering hormone receptors (ETHR) regulate the behavioral sequence necessary for cuticle shedding. Recent reports have documented functions for ETHR signaling in adult Drosophila melanogaster. In this study, we report that ETHR silencing in local interneurons of the antennal lobes and fruitless neurons leads to sharply increased rates of male-male courtship.

Postprandial sleep mechanics in .

Food consumption is thought to induce sleepiness. However, little is known about how postprandial sleep is regulated. Here, we simultaneously measured sleep and food intake of individual flies and found a transient rise in sleep following meals.

Mifepristone Reduces Food Palatability and Affects Drosophila Feeding and Lifespan.

The Drosophila GeneSwitch system facilitates the spatial and temporal control of gene expression through dietary supplementation of mifepristone (RU486). Because experimental and control groups differ only by treatment with RU486, confounding results from using flies of different genetic backgrounds are eliminated, making GeneSwitch especially useful in studies of aging. However, the effect of RU486 itself on longevity has not been well characterized, particularly in relation to nutritional states known to affect lifespan.

Acidic Food pH Increases Palatability and Consumption and Extends Drosophila Lifespan.

Background: Despite the prevalent use of Drosophila as a model in studies of nutrition, the effects of fundamental food properties, such as pH, on animal health and behavior are not well known.

Objectives: We examined the effect of food pH on adult Drosophila lifespan, feeding behavior, and microbiota composition and tested the hypothesis that pH-mediated changes in palatability and total consumption are required for modulating longevity.

Methods: We measured the effect of buffered food (pH 5, 7, or 9) on male gustatory responses (proboscis extension), total food intake, and male and female lifespan.

Microbes Promote Amino Acid Harvest to Rescue Undernutrition in Drosophila.

Microbes play an important role in the pathogenesis of nutritional disorders such as protein-specific malnutrition. However, the precise contribution of microbes to host energy balance during undernutrition is unclear. Here, we show that Issatchenkia orientalis, a fungal microbe isolated from field-caught Drosophila melanogaster, promotes amino acid harvest to rescue the lifespan of undernourished flies.

Quantifying Drosophila food intake: comparative analysis of current methodology.

Food intake is a fundamental parameter in animal studies. Despite the prevalent use of Drosophila in laboratory research, precise measurements of food intake remain challenging in this model organism. Here, we compare several common Drosophila feeding assays: the capillary feeder (CAFE), food labeling with a radioactive tracer or colorimetric dye and observations of proboscis extension (PE).