Biology subjects

Shohat-Ophir, G.

Publications and source records attributed to Shohat-Ophir, G..

9 recordsLinked to original sources

bioRxiv2026

A comprehensive CRISPR screen of the Drosophila glutamate receptome reveals Ekar as a selective regulator of presynaptic homeostatic plasticity

Homeostatic mechanisms protect synapses from destabilizing challenges throughout an organisms lifespan, ensuring stable yet flexible neural network activity. To delineate the molecular basis of presynaptic homeostatic potentiation (PHP), we conducted a comprehensive, in vivo CRISPR/Cas9-based screen of all 16 glutamate receptor (GluR) genes encoded in the Drosophila genome. We first generated a complete expression atlas across larval and adult stages, identifying nine GluRs expressed in presynaptic motor neurons. We then generated null mutants for all 16 GluRs and screened them at the larval neuromuscular junction. While the loss of any single presynaptic GluR did not affect baseline synaptic growth or neurotransmission, our screen revealed a selective and critical requirement for the kainate receptor subunit ekar in the expression of chronic PHP. Further genetic analysis indicates that Ekar functions coordinately with the kainate receptor subunits KaiRID and Ukar within a shared pathway to promote this plasticity. Mechanistically, Ekar acts downstream of active zone remodeling to drive the homeostatic enhancement of presynaptic Ca2+ influx, which is the defining feature of chronic PHP. Together, this genome-wide analysis establishes a definitive functional atlas for the Drosophila glutamate receptome and highlights a specialized, essential role for Ekar in stabilizing long-term synaptic homeostasis.

neuroscience↗

bioRxiv2025

Identity Domains Reveal How Life Experiences and the Microbiome Shape Individuality and Uncover the Presence of Social Memory in Drosophila

Personality is comprised of enduring traits that shape behavior across contexts and over time. Yet outside humans, research often equates individuality with personality, focusing on how one animal differs from another in each behavior. This overlooks the latent space that spans an animals behavioral repertoire, how it is shaped by innate tendencies and prior experiences, and how it differs from transient factors. Here, we bridge this gap by integrating a data-driven framework with unbiased trait interpretation via large language models, revealing how social, sexual, and physiological conditions systematically alter the expression of personality-like traits in Drosophila melanogaster. This approach yielded four identities: space-use (exploration), time-use (social investment), avoidance, and aggression. Large language models produced strong consensus on the interpretation of some of these axes and divergence on others. These dimensions proved stable within individuals yet shifted predictably following mating, isolation, and microbiome manipulation, often in sex dependent ways. Notably, flies behaved differently toward familiar and unfamiliar peers, revealing a capacity for social memory. These findings bridge temperament and personality, showing how life history reshapes baseline tendencies into individualized profiles within constrained dimensions. They establish Drosophila as a tractable system for uncovering the biological logic of personality and advancing cross-species principles for individuality research. Significance StatementPersonality is often treated as a hallmark of complex brains, yet we show that fruit flies express stable behavioral identities with systematic, experience driven plasticity. Using a mathematical framework, we resolve four stable traits and map how sex, social experience, and the gut microbiome shift their expression. We further demonstrate social recognition in flies: they treat familiar cage mates differently from newcomers over repeated encounters, evidencing social memory, a striking result given their simple nervous system. Finally, we introduce large language models to provide objective, reproducible interpretations of trait dimensions, reducing human bias. These advances establish a general, quantitative approach to personality and social behavior in a tractable genetic model.

neuroscience↗

bioRxiv2025

Cell-type-resolved RNA-seq reveals molecular engrams of sexual experience in Drosophila neuromodulatory neurons.

Flexible behavioral responses rely on the ability of neural circuits to adapt their physiology and output to changing social and environmental contexts. Neuromodulation plays a central role in this flexibility, dynamically tuning neuronal activity and gene expression to align behavior with experience and internal states. Yet how specific experiences and motivational conditions are encoded within neuromodulatory neurons remains underexplored. Here, we show that distinct motivational outcomes drive discrete, largely non-overlapping transcriptional programs across three neuromodulatory neuronal populations in male Drosophila brains. Using cell-type-resolved RNA sequencing, we profiled the transcriptomes of serotonergic (Trh), octopaminergic/tyraminergic (Tdc2), and neuropeptide F receptor (NPFR) neurons under three conditions: successful mating, sexual rejection, and the absence of social or sexual interaction. Each experience induced a unique "molecular engram" within specific neuron types. NPFR neurons exhibited the strongest transcriptional remodeling following rejection, Tdc2 neurons preferentially represented the naive-single state, and Trh neurons displayed balanced, experience-specific tuning. Shared differentially expressed genes across neuronal classes were few and often were oppositely regulated, revealing divergent circuit-specific logic. Experience triggered multilayered reprogramming across chromatin organization, RNA metabolism, translation, proteostasis and synaptic machinery, with selective recalibration of vesicle trafficking, and neuroplasticity. We further identified a compact, cross-circuit "rejection core" enriched for circadian, stress, metabolic, neuropeptidergic, and synaptic components. Together, these findings demonstrate how neuromodulatory circuits translate social experience into coordinated molecular and synaptic adaptations that enable behavioral flexibility.

neuroscience↗

bioRxiv2023

A highly conserved A-to-I RNA editing event within the glutamate-gated chloride channel GluClα is necessary for olfactory-based behaviors in Drosophila

A-to-I RNA editing is an important cellular process that modifies genomically encoded information during transcription, to generate various RNA isoforms from a single DNA sequence. It involves the conversion of specific adenosines in the RNA sequence to inosines by ADAR proteins, resulting in their recognition as guanosines by cellular machinery, and as such plays a vital role in neuronal and immune functions. Given the widespread occurrence of A-to-I RNA editing events across the animal kingdom, with thousands to millions of editing sites found in the transcriptomes of organisms such as flies and humans, identifying the critical sites and understanding their in-vivo functions remains a challenging task. Here we show for the first time the physiological importance of a single editing site, found within the extracellular domain of the glutamate-gated chloride channel (GluCl), and bridge the gap between its evolutionary conservation across Drosophila species and its function in shaping the behavior of adult flies. We used genomic editing to ablate editing at this specific site, such that the endogenous channel harbors only the unedited version and used a battery of behavioral paradigms to analyze the effects on various features of adult behavior. We provide evidence that GluClunedited flies exhibit reduced olfactory responses to both appetitive and aversive odors, as well as impaired pheromone-dependent social interactions, and that editing of this site is required for proper processing of olfactory information in olfactory projection neurons. Our findings demonstrate that evolutionary conservation is a useful criterion to pinpoint which of the many editing events has the potential of having a function and pave the path for dissecting the link between RNA modification, neuronal physiology, and behavior.

neuroscience↗

bioRxiv2022

Sexual deprivation induces a CRF independent stress response and decreases resistance to stressors in Drosophila via a subpopulation of Neuropeptide F receptor-expressing neurons

Living in a changing environment composed of other behaving animals entails both opportunities and challenges to obtain resources and mating partners. Actions that promote survival and reproduction are reinforced by the brain reward systems, whereas coping with the challenges associated with obtaining these rewards are mediated by stress response pathways. The activation of the latter can impair health and shorten lifespan. Although similar responses to social opportunity and challenge exist across the animal kingdom, little is known about the mechanisms that process reward and stress under different social conditions. Here, we studied the interplay between deprivation of sexual reward and stress response in Drosophila melanogaster and discovered that repeated failures to obtain sexual reward induces a frustration-like state that is characterized by increased arousal, persistent sexual motivation, and impaired ability to cope with starvation and oxidative stressors. We show that this increased arousal and sensitivity to starvation is mediated by disinhibition of neurons that express receptors for the fly homologue of neuropeptide Y (neuropeptide F, NPF). We furthermore demonstrate the existence of an anatomical overlap between stress and reward systems in the fly brain in the form of neurons that co-express receptors for NPF (NPFR) and the corticotropin-releasing factor (CRF)-like homologue Diuretic hormone 44 (Dh44), and that deprivation of sexual reward leads to translocation of forkhead box-subgroup O (FoxO) to the cytoplasm in these neurons. Nevertheless, the activity of Dh44 neurons alone does not mediate sensitivity to starvation and aroused behavior following sexual deprivation, instead, these responses are mediated by disinhibition of ~12-16 NPFR-expressing neurons via a dynamin-independent synaptic signaling mechanism, suggesting the existence of a NPFR mediated stress pathway which is Dh44-independent. This paves the path for using simple model organisms to dissect mechanisms behind anticipation of reward, and more specifically, to determine what happens when expectations to obtain natural and drug rewards are not met.

animal behavior and cognition↗

bioRxiv2021

Sexual deprivation modulates social interaction and reproductive physiology

Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward system, less attention has been given to the consequences of failure to obtain a desirable reward. As a model system to study the impact of failure to obtain a natural reward, we used the well-established courtship suppression paradigm in Drosophila melanogaster as means to induce repeated failures to obtain sexual reward in male flies. We discovered that beyond the known reduction in courtship actions caused by interaction with non-receptive females, repeated failures to mate induce a stress response characterized by persistent motivation to obtain the sexual reward, reduced male-male social interaction, and enhanced aggression. This frustrative-like state caused by the conflict between high motivation to obtain sexual reward and the inability to fulfill their mating drive impairs the capacity of rejected males to tolerate stressors such as starvation and oxidative stress. We further show that sensitivity to starvation and enhanced social arousal is mediated by the disinhibition of a small population of neurons that express receptors for the fly homologue of neuropeptide Y. Our findings demonstrate for the first time the existence of social stress in flies and offers a framework to study mechanisms underlying the crosstalk between reward, stress, and reproduction in a simple nervous system that is highly amenable to genetic manipulation.

animal behavior and cognition↗

bioRxiv2020

Transcriptome Analysis of NPFR Neurons Reveals a Connection Between proteome Diversity and Social Behavior

Complex social behaviors are mediated by the activity of highly intricate neuronal networks, the function of which is shaped by their transcriptomic and proteomic content. Contemporary advances in neurogenetics, genomics, and tools for automated behavior analysis make it possible to functionally connect the transcriptome profile of candidate neurons to their role in regulating behavior. In this study we used Drosophila melanogaster to explore the molecular signature of neurons expressing receptor for neuropeptide F (NPF), the fly homologue of neuropeptide Y (NPY). By comparing the transcription profile of NPFR neurons to those of nine other populations of neurons, we discovered that NPFR neurons exhibit a unique transcriptome, enriched with receptors for various neuropeptides and neuromodulators, as well as with genes known to regulate behavioral processes, such as learning and memory. By manipulating RNA editing and protein ubiquitination programs specifically in NPFR neurons, we demonstrate that their delicate transcriptome and proteome repertoires are required to suppress male courtship and certain features of social group interaction. Our results highlight the importance of transcriptome and proteome diversity in the regulation of complex behaviors and pave the path for future dissection of the spatiotemporal regulation of genes within highly complex tissues, such as the brain.

neuroscience↗

bioRxiv2020

Social interaction and network structure in groups of Drosophila are shaped by prior social experience and group composition

Living in a group creates a complex and dynamic environment in which the behavior of the individual is influenced by and affects the behavior of others. Although social interactions and group living are fundamental adaptations exhibited by many organisms, relatively little is known about how prior social experience, internal states and group composition shape behavior in a group, and the neuronal and molecular mechanisms that mediate it. Here we present a practical framework for studying the interplay between social experience and group interaction in Drosophila melanogaster and show that the structure of social networks and group interactions are sensitive to group composition and individuals social experience. We simplified the complexity of interactions in a group using a series of experiments in which we controlled the social experience and motivational states of individuals to dissect patterns that represent distinct structures and behavioral responses of groups under different social conditions. Using high-resolution data capture, machine learning and graph theory, we analyzed 60 distinct behavioral and social network features, generating a comprehensive representation ("group signature") for each condition. We show that social enrichment promotes the formation of a distinct group structure that is characterized by high network modularity, high inter-individual and inter-group variance, high inter-individual coordination, and stable social clusters. Using environmental and genetic manipulations, we show that this structure requires visual and pheromonal cues, and that cVA sensing neurons are necessary for the expression of different aspects of social interaction in a group. Finally, we explored the formation of group behavior and structure in heterogenous groups composed of flies with distinct internal states, and discovered evidence suggesting that group structure and dynamics reflect a level of complexity that cannot be explained as a simple average of the individuals that constitute it. Our results demonstrate that fruit flies exhibit complex and dynamic social structures that are modulated by the experience and composition of different individuals within the group. This paves the path for using simple model organisms to dissect the neurobiology of behavior in complex social environments.

neuroscience↗

bioRxiv2018

Illuminating spatial A-to-I RNA editing signatures within the Drosophila brain

SummaryAdenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a ubiquitous mechanism that generates transcriptomic diversity. This process is particularly important for proper neuronal function; however, little is known about how RNA editing is dynamically regulated between the many functionally distinct neuronal populations of the brain. In this resource paper, we present a spatial RNA editing map in the Drosophila brain and show that different neuronal populations possess distinct RNA editing signatures. After purifying and sequencing RNA from genetically marked neuronal nuclei, we identified a large number of novel editing sites and compared editing levels in hundreds of transcripts across nine functionally different neuronal populations. We found distinct editing repertoires for each population, including novel sites in repeat regions of the transcriptome and differential editing in highly conserved and likely functional regions of transcripts that encode essential neuronal genes. These changes are site-specific and not driven by changes in Adar expression, suggesting a complex, targeted regulation of editing levels in key transcripts. This fine-tuning of the transcriptome between different neurons by RNA editing may account for functional differences between distinct populations in the brain.\n\nSignificance StatementA fundamental question in contemporary neuroscience is how the remarkable cellular diversity required for the intricate function of the nervous system is achieved. In this manuscript, we bridge the gap between a cellular machinery that is known to diversify the transcriptome and the existence of distinct neuronal populations that compose Drosophila brain. Adenosine-to-inosine (A-to-I) RNA-editing is a ubiquitous mechanism that generates transcriptomic diversity in cells by recoding certain adenosines within the pre-mRNA sequence into inosines. We present a spatial map of RNA editing across different neuronal populations in Drosophila brain. Each neuronal population has a distinct editing signature, with the majority of differential editing occurring in highly conserved regions of transcripts that encode ion channels and other essential neuronal genes.

neuroscience↗