Tracking Sugar-Elicited Local Searching Behavior in Drosophila.

Foraging behavior is essential for the survival of organisms as it enables them to locate and acquire essential food resources. In Drosophila, hunger triggers a distinct search behavior following the consumption of small quantities of a sugar solution. This report presents a simple experimental setup to study sugar-elicited search behavior with the aim of uncovering the underlying mechanisms.

A gain-of-function mutation in , causes precocious cell death of wing epidermal cells in .

In , wing epidermal cells undergo programmed cell death as the last step of metamorphosis. The aim of this study was to evaluate the role of , particularly the mutation ( ), an allele of , in the cell death. The wing epithelial cell death is suppressed by loss-of-function mutation of , indicating that the death is governed by a cascade involving .

A conserved odorant binding protein is required for essential amino acid detection in Drosophila.

Animals need to detect in the food essential amino acids that they cannot synthesize. We found that the odorant binding protein OBP19b, which is highly expressed in taste sensilla, is necessary for the detection of several amino acids including the essential l-phenylalanine. The recombinant OBP19b protein was produced and characterized for its binding properties: it stereoselectively binds to several amino acids.

Softness sensing and learning in larvae.

Mechanosensation provides animals with important sensory information in addition to olfaction and gustation during feeding behavior. Here, we used larvae to investigate the role of softness sensing in behavior and learning. In the natural environment, larvae need to dig into soft foods for feeding.

Sugar Intake Elicits Intelligent Searching Behavior in Flies and Honey Bees.

We present a comparison of the sugar-elicited search behavior in and . In both species, intake of sugar-water elicits a complex of searching responses. The most obvious response was an increase in turning frequency.

Octopamine and Tyramine Contribute Separately to the Counter-Regulatory Response to Sugar Deficit in .

All animals constantly negotiate external with internal demands before and during action selection. Energy homeostasis is a major internal factor biasing action selection. For instance, in addition to physiologically regulating carbohydrate mobilization, starvation-induced sugar shortage also biases action selection toward food-seeking and food consumption behaviors (the counter-regulatory response).

Deciphering the Genes for Taste Receptors for Fructose in .

Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In , recent studies have identified several gustatory receptor () genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars.

Pharyngeal stimulation with sugar triggers local searching behavior in .

Foraging behavior is essential for all organisms to find food containing nutritional chemicals. A hungry fly performs local searching behavior after drinking a small amount of sugar solution. Using video tracking, we examined how the searching behavior is regulated in We found that a small amount of highly concentrated sugar solution induced a long-lasting searching behavior.

The Olmpiad: concordance of behavioural faculties of stage 1 and stage 3 larvae.

Mapping brain function to brain structure is a fundamental task for neuroscience. For such an endeavour, the larva is simple enough to be tractable, yet complex enough to be interesting. It features about 10,000 neurons and is capable of various taxes, kineses and Pavlovian conditioning.

Pavlovian Conditioning of Larval : An Illustrated, Multilingual, Hands-On Manual for Odor-Taste Associative Learning in Maggots.

Larval offer a study case for behavioral neurogenetics that is simple enough to be experimentally tractable, yet complex enough to be worth the effort. We provide a detailed, hands-on manual for Pavlovian odor-reward learning in these animals. Given the versatility of for genetic analyses, combined with the evolutionarily shared genetic heritage with humans, the paradigm has utility not only in behavioral neurogenetics and experimental psychology, but for translational biomedicine as well.

genes form an oscillatory loop independent of the / loop in the circadian clockwork of the cricket .

Background: Animals exhibit circadian rhythms with a period of approximately 24 h in various physiological functions, including locomotor activity. This rhythm is controlled by an endogenous oscillatory mechanism, or circadian clock, which consists of cyclically expressed clock genes and their product proteins. () genes are thought to be involved in the clock mechanism, and their functions have been examined extensively in holometabolous insects, but in hemimetabolous insects their role is less well understood.

Mated Drosophila melanogaster females consume more amino acids during the dark phase.

To maintain homeostasis, animals must ingest appropriate quantities, determined by their internal nutritional state, of suitable nutrients. In the fruit fly Drosophila melanogaster, an amino acid deficit induces a specific appetite for amino acids and thus results in their increased consumption. Although multiple processes of physiology, metabolism, and behavior are under circadian control in many organisms, it is unclear whether the circadian clock also modulates such motivated behavior driven by an internal need.

Preference for and learning of amino acids in larval .

Relative to other nutrients, less is known about how animals sense amino acids and how behaviour is organized accordingly. This is a significant gap in our knowledge because amino acids are required for protein synthesis - and hence for life as we know it. Choosing larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical amino acids in We report that preference for individual amino acids differs according to the kind of amino acid, both in first-instar and in third-instar larvae.

Genetic Variation in Taste Sensitivity to Sugars in Drosophila melanogaster.

Taste sensitivity plays a major role in controlling feeding behavior, and alterations in feeding habit induced by changes in taste sensitivity can drive speciation. We investigated variability in taste preferences in wild-derived inbred lines from the Drosophila melanogaster Genetic Reference Panel. Preferences for different sugars, which are essential nutrients for fruit flies, were assessed using two-choice preference tests that paired glucose with fructose, sucrose, or trehalose.

Function of desiccate in gustatory sensilla of drosophila melanogaster.

Desiccate (Desi), initially discovered as a gene expressing in the epidermis of Drosophila larvae for protection from desiccation stress, was recently found to be robustly expressed in the adult labellum; however, the function, as well as precise expression sites, was unknown. Here, we found that Desi is expressed in two different types of non-neuronal cells of the labellum, the epidermis and thecogen accessory cells. Labellar Desi expression was significantly elevated under arid conditions, accompanied by an increase in water ingestion by adults.

Learning the specific quality of taste reinforcement in larval Drosophila.

The only property of reinforcement insects are commonly thought to learn about is its value. We show that larval Drosophila not only remember the value of reinforcement (How much?), but also its quality (What?). This is demonstrated both within the appetitive domain by using sugar vs amino acid as different reward qualities, and within the aversive domain by using bitter vs high-concentration salt as different qualities of punishment.

Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila.

A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms with shorter periods. We used a video-tracking method to monitor the movement of single flies, and clear ultradian rhythms were detected in the locomotor behaviour of wild type and clock mutant flies kept under constant dark conditions.

Genetic variation in food choice behaviour of amino acid-deprived Drosophila.

To understand homeostatic regulation in insects, we need to understand the mechanisms by which they respond to external stimuli to maintain the internal milieu. Our previous study showed that Drosophila melanogaster exhibit specific amino acid preferences. Here, we used the D.

C-terminal binding protein (CtBP) activates the expression of E-box clock genes with CLOCK/CYCLE in Drosophila.

In Drosophila, CLOCK/CYCLE heterodimer (CLK/CYC) is the primary activator of circadian clock genes that contain the E-box sequence in their promoter regions (hereafter referred to as "E-box clock genes"). Although extensive studies have investigated the feedback regulation of clock genes, little is known regarding other factors acting with CLK/CYC. Here we show that Drosophila C-terminal binding protein (dCtBP), a transcriptional co-factor, is involved in the regulation of the E-box clock genes.

Suppression of conditioned odor approach by feeding is independent of taste and nutritional value in Drosophila.

Motivation controls behavior [1]. A variety of food-related behaviors undergo motivational modulation by hunger, satiety, and other states [2-4]. Here we searched for critical satiation factors modulating approach to an odor associated with sugar reward in Drosophila melanogaster.

Gustatory sensing mechanism coding for multiple oviposition stimulants in the swallowtail butterfly, Papilio xuthus.

The swallowtail butterfly, Papilio xuthus, selectively uses a limited number of plants in the Rutaceae family. The butterfly detects oviposition stimulants in leaves through foreleg chemosensilla and requires a specific combination of multiple oviposition stimulants to lay eggs on the leaf of its host plants. In this study, we sought to elucidate the mechanism underlying the regulation of oviposition behavior by multiple oviposition stimulants.

Effects of overexpression of mitochondrial transcription factor A on lifespan and oxidative stress response in Drosophila melanogaster.

Mitochondrial transcription factor A (TFAM) plays a role in the maintenance of mitochondrial DNA (mtDNA) by packaging mtDNA, forming the mitochondrial nucleoid. There have been many reports about a function of TFAM at the cellular level, but only a few studies have been done in individual organisms. Here we examined the effects of TFAM on the Drosophila lifespan and oxidative stress response, by overexpressing TFAM using the GAL4/UAS system.

Taste preference for amino acids is dependent on internal nutritional state in Drosophila melanogaster.

Like mammals, insects need to ingest proteins from foods because they cannot synthesise several amino acids. Amino acids are also essential nutrients for Drosophila melanogaster, especially for female egg production, but how flies detect amino acids and how the feeding response to amino acids is regulated are unknown. In this study, the two-choice preference test, the proboscis extension reflex test and a CAFE assay were performed to explore the ability of D.

A gustatory receptor involved in host plant recognition for oviposition of a swallowtail butterfly.

Swallowtail butterflies belonging to the family of Papilionidae selectively utilize a limited number of plants from a single or a few families. Female butterflies lay eggs on their host only when they detect specific chemicals through their foreleg chemosensilla while drumming on the leaf surface. Here we show that the butterfly, Papilio xuthus, uses a gustatory receptor specific for synephrine to select its host in oviposition behaviour.

Membrane-bound transporter controls the circadian transcription of clock genes in Drosophila.

Little is known about molecular mechanisms that control the Drosophila circadian clock beyond the transcriptional-translational feedback regulation of clock genes as an intracellular process. In this study, Early gene at 23 (E23) was identified as a novel clock gene that encodes the membrane-bound ABC transporter that is induced by the molting hormone ecdysone. E23 expresses in pacemaker neurons in fly head, and its knockdown flies lengthened circadian period with an increased expression of the clock gene vrille.