Show threadAlbert Cardona4h ago

@katvogt

That last point on "a locomotor adaptation model accounts for most direct returns" reminds me very much of the #Drosophila larva local search:

"Finding a path: Local search behavior of Drosophila larvae", Kromp et al. 2024 (Andreas Thum's lab)
https://www.biorxiv.org/content/10.1101/2024.11.21.624685v1

#DrosophilaLarva #foraging #SearchStrategies #neuroscience

Finding a path: Local search behavior of Drosophila larvae

Orientation and navigation are essential features of animals living in changing environments. Typically, animals integrate a variety of allothetic and idiothetic cues to achieve their navigational goals. Allothetic cues, such as visual or chemical landmarks from the environment, provide an external frame of reference. In contrast, idiothetic cues are based on internal proprioceptive feedback and internal copies of motor commands. When Drosophila larvae are exposed briefly to a Teflon container holding a food stimulus, they show a characteristic behavior as soon as the container is removed: They briefly crawl away from the detected resource, remain in its vicinity and then return to the area where they experienced the earlier stimulus. We quantified this behavior with respect to the chemosensory nature of the stimulus, starvation time of the larvae, and agarose concentration of the test plate substrate. We conclude that this behavior represents a centered local search. Furthermore, we exclude various external stimuli (vision and taste), which suggests that possibly idiothetic as opposed to allothetic cues have a stronger influence on the larval local search behavior. In the long term, this behavioral description will enable us to gain insights into the comparability of larval foraging strategies. We also want to investigate whether, despite the simpler organization of the larval brain and the alleged lack of a central complex, a brain region that is important for orientation and navigation in adult Drosophila and other insects, there are common solutions for the brain circuits underlying search behavior. ### Competing Interest Statement The authors have declared no competing interest. * AM : amyl acetate Crv : center revisits CX : central complex EB : ellipsoid body E-PG : ellipsoid body-protocerebral bridge-gall neurons FB : fan-shaped body GRN : gustatory receptor neuron MB : mushroom body NO : noduli OR : olfactory receptor ORN : olfactory receptor neuron PB : protocerebral bridge WT-CS : wild type Canton-S

bioRxiv
Show threadAlbert Cardona4h ago

@katvogt

On the same topic:

"Recent experience and internal state shape local search strategies in flies", Goldschmidt et al. (Hannah Haberken's lab)
https://www.sciencedirect.com/science/article/pii/S0960982226001648

* Search driven by real food expands, shifting with satiety from short to long trips
* Purely gustatory-induced searches are shorter without scaling
* A locomotor adaptation model accounts for most direct returns in long trips

#Drosophila #foraging #SearchStrategies #neuroscience

Albert Cardona4h ago

"Along with with the group of Katrin Vogt @katvogt at the University of Konstanz, we combine long timescale (3 hours) behavioral tracking of #Drosophila larvae in controlled patchy environments with varying statistics, along with quantitative analysis and computational modeling, to dissect foraging decision strategies. Drosophila larvae adjusted their foraging depending on the environmental parameters: patch quality, patch valence and both simultaneously. We were able to recapitulate these dynamics using a simple integration model." – Ahmed El Hady

"Environmental statistics and sensory experience shape patch foraging strategies in Drosophila larvae", Mudunuri et al.
https://www.biorxiv.org/content/10.64898/2026.03.27.714746v1

#neuroscience #foraging #DrosophilaLarva

Environmental statistics and sensory experience shape patch foraging strategies in Drosophila larvae

Animals foraging in patchy environments must balance exploiting current resources with exploring for better alternatives to maximize resource intake and to survive. However, the neural and computational mechanisms underlying such adaptive decisions have just recently begun to be understood. Using Drosophila larvae as an experimentally tractable model, we combine long-timescale behavioral tracking in controlled patchy environments with varying statistics, along with quantitative analysis and computational modeling, to dissect foraging decision strategies. We show that larvae flexibly adjust their behavior according to both the quality and valence of available resources, shaped by prior foraging experience. A simple integration model recapitulates larval patch-leaving behavior, with model parameters tuned by environmental statistics and foraging history. Together, these findings establish Drosophila larvae as a powerful system for studying adaptive foraging and for uncovering the neural circuit mechanisms that implement experience-dependent foraging decisions. ### Competing Interest Statement The authors have declared no competing interest. Deutsche Forschungsgemeinschaft, EXC 2117-422037984 International Human Frontier Science Program Organization, RGP006/2025

bioRxiv
flypapers1d ago
📰 "Temperature-sensitive cytoplasmic incompatibility across divergent Wolbachia partly reflects cifB transcription, not endosymbiont density"
https://www.biorxiv.org/content/10.64898/2026.03.31.715596v1?rss=1
#Drosophila
Temperature-sensitive cytoplasmic incompatibility across divergent Wolbachia partly reflects cifB transcription, not endosymbiont density

Maternally transmitted Wolbachia bacteria are common in insects, with many strains altering host reproduction through cytoplasmic incompatibility (CI). CI kills embryos fertilized by Wolbachia -bearing males unless those embryos also carry Wolbachia , which favors females with Wolbachia and drives the endosymbiont to higher frequencies in host populations. Strong CI now underpins successful applications that rely on maintaining pathogen-blocking Wolbachia transinfections in vector populations to reduce arboviral disease transmission. Temperature modulates CI strength (the proportion of embryos killed), with consequences for Wolbachia prevalence in natural and transinfected populations. Yet the mechanisms regulating temperature-sensitive CI-strength variation are poorly understood. We quantified CI strength across eight divergent Drosophila -associated Wolbachia strains at four temperatures (18°C–26°C), while characterizing development time, Wolbachia and Wovirus densities, and transcription of the CI-inducing gene cifB . Four of eight Wolbachia strains exhibited temperature-sensitive CI, three of which induced CI at multiple temperatures. Of these three, two expressed significantly more cifB at the temperature yielding stronger CI, whereas testes Wolbachia density did not predict CI strength. Notably, cifB -transcript levels were consistently decoupled from Wolbachia and Wovirus densities, suggesting that cifB transcription is not regulated solely by symbiont abundance. We also report temperature-sensitive rescue of CI, Wolbachia -associated developmental acceleration, and strain-specific Wovirus - Wolbachia covariance. Our findings reveal temperature as a pervasive modulator of Wolbachia -host interactions at multiple levels and extend evidence that cifB transcription partly predicts variable CI strength across strain identities, male ages, and now temperatures. CI variation unaccounted for by cifB transcription points toward additional regulatory or post-transcriptional mechanisms that we discuss. ### Competing Interest Statement The authors have declared no competing interest. U.S. National Science Foundation, 2145195, DBI-2010210 National Institutes of Health, https://ror.org/01cwqze88, R35GM124701, P20GM103474 M J Murdock Charitable Trust, https://ror.org/02hxgd925, 202324717 Lehigh University, https://ror.org/012afjb06 University of Montana, https://ror.org/0078xmk34

bioRxiv
flypapers1d ago
📰 "Conserved but mechanistically diverse piRNA defence against endogenous retroviruses in insects"
https://doi.org/doi:10.1038/s44319-026-00741-4
https://pubmed.ncbi.nlm.nih.gov/41922845/
#Drosophila
Conserved but mechanistically diverse piRNA defence against endogenous retroviruses in insects - EMBO Reports

Defence systems against genetic mobile elements are highly adaptable, yet their long-term evolutionary stability remains unclear. To address this, we examined the conservation of Piwi-interacting RNA (piRNA)-mediated defence against envelope-carrying gypsy long terminal repeat (LTR) retrotransposons across insects beyond Drosophila. We show that Aedes aegypti (yellow fever mosquito) and Anopheles stephensi (Asian malaria mosquito), as well as Tetragonula carbonaria (stingless bees), Acheta domesticus (house cricket) and Teleogryllus oceanicus (Pacific field cricket), all produce piRNAs targeting gypsy elements in ovarian somatic cells—the same cellular niche where Drosophila mounts piRNA defence against gypsy—indicating a persistent arms race for more than 400 million years of insect evolution. Notably, in Aedes aegypti, ovarian somatic cells express the same piRNA clusters as other somatic tissues, where they are known to target RNA viruses—suggesting a shared origin of anti-viral and anti-retrotransposon defences. Furthermore, we observe lineage-specific differences in ovarian somatic piRNA biogenesis: slicing-independent phasing appears to dominate in dipterans, ping-pong amplification in bees, and slicing-dependent phasing in crickets. Together, these findings indicate that distinct piRNA pathways have independently evolved at different timepoints to silence the same class of retrotransposons in insect evolution.

SpringerLink
flypapers1d ago
📰 "Adhesion to a common ECM mediates interdependence in tissue morphogenesis in Drosophila"
https://doi.org/doi:10.1038/s44319-026-00754-z
https://pubmed.ncbi.nlm.nih.gov/41922843/
#Drosophila
Adhesion to a common ECM mediates interdependence in tissue morphogenesis in Drosophila - EMBO Reports

Organ functionality requires the precise coordination of diverse tissues during development. Halfway through Drosophila embryogenesis, two lateral epidermal sheets stretch to fuse at the dorsal midline; concomitant with this, the main tubes of the respiratory system also shift dorsally. Here, we demonstrate that these processes occur simultaneously and are coordinated by the adhesion of the epidermal sheets and a subset of cells of the tracheal trunks to a common extracellular matrix (ECM) that separates them. We also show that during dorsal closure, tracheal trunk cells extend protrusions towards the ECM underneath the epidermis. These protrusions are under tension, suggesting that they have a mechanical function. Additionally, perturbing adhesion between tracheal cells and the epidermis affects the development of both tissues. Altogether, our findings uncover a mechanism used for tissue coordination during development, one that is based on tissue adhesion towards a common ECM capable of transmitting mechanical forces across the embryo.

SpringerLink
flypapers1d ago
📰 "Caspase-3/Drice as a critical regulator of actin dynamics through its dual control of small RhoGTPase family and Gelsolin in the Malpighian tubules of Drosophila"
https://doi.org/doi:10.1038/s41420-026-03061-7
https://pubmed.ncbi.nlm.nih.gov/41922321/
#Drosophila #Immunity
flypapers1d ago
📰 "Intrinsic diversity in odor-evoked calcium rises across Drosophila olfactory neurons"
https://doi.org/doi:10.1523/JNEUROSCI.2132-25.2026
https://pubmed.ncbi.nlm.nih.gov/41922183/
#Drosophila
Intrinsic diversity in odor-evoked calcium rises across Drosophila olfactory neurons

Across species, olfactory receptor neurons (ORNs) exhibit stimulus-driven changes in gene expression, with calcium as a key activity signal. However, it remains unclear whether neuronal activity elevates intracellular calcium with differential gain across ORN types, which could then disparately influence a neuron’s propensity for activity-dependent modulation. To address this possibility, we combined simultaneous electrophysiology and calcium imaging to systematically map odor-evoked calcium gain across the majority of characterized Drosophila ORN types of either sex. Despite comparable spike rates, calcium signals can differ by more than tenfold. Within each ORN, calcium scaled linearly with spiking, yet the slope varied markedly across neuron types. Mechanistically, calcium gain was intrinsic to ORN type, independent of receptor identity, and differentially regulated in distinct ORNs by internal calcium store and voltage-dependent calcium entry. These findings reveal striking heterogeneity in odor-evoked calcium gain, with implications for how individual ORNs interpret odor activation to differentially engage activity-dependent processes and plasticity. Significance statement Our study assayed the majority of Drosophila olfactory receptor neurons using simultaneous electrophysiology and calcium imaging. Using spike activity as the ground truth, we found strikingly diverse, cell type-specific calcium rises across the ORN repertoire. Mechanistically, cell-specific genetic manipulations revealed distinct channel requirements for spike-to-calcium coupling, independent of receptor identity. Given calcium’s role as a central signaling molecule in transduction, plasticity, and numerous other cellular processes, defining how spikes translate into calcium signals across neuron types provides essential insight into how olfactory neurons interpret odor activation and engage activity-dependent processes.

Journal of Neuroscience
flypapers1d ago
📰 "IMDD: A Database for Exploring Tissue-Specific Gene Expression Dynamics During Holometabolous Insects"
https://doi.org/doi:10.1016/j.jmb.2026.169781
https://pubmed.ncbi.nlm.nih.gov/41921848/
#DrosophilaMelanogaster
#Drosophila
flypapers1d ago
📰 "Non-random brain connectome wiring enables robust and efficient neural network function under high sparsity"
https://www.biorxiv.org/content/10.64898/2026.03.30.715411v1?rss=1
#DrosophilaMelanogaster
#Drosophila #Metabolism
Non-random brain connectome wiring enables robust and efficient neural network function under high sparsity

The connectivity of brain networks is extremely sparse due to metabolic, physical and spatial constraints. Although wiring sparsity can confer computational advantages for biological and artificial neural networks, sparse networks require fine parameter tuning and exhibit strong sensitivity to perturbations. How brains achieve their efficiency and robustness is unclear. Here we addressed this by analysing the dynamical properties of Echo State Networks with wiring based on the Drosophila melanogaster fruit fly connectome, compared with sparsity-matched random-wiring networks. We evaluated these networks on a set of eight cognitive tasks, and found that connectome-based neural networks (CoNNs) typically showed narrowly distributed task engagement across their neurons. The importance of a neuron for task performance correlated with its node degree, local clustering, and self-recurrency, and these correlations were stronger in CoNNs than in random networks. CoNNs were more robust to neuronal loss, retaining their task performance and beneficial dynamical properties such as criticality and spectral radius better than random networks. Similarly, CoNNs were more robust to hyperparameter variations in both input and recurrent weight scaling. Using theoretical arguments and numerical simulations, we show that excess CoNN node self-recurrency is sufficient to explain this enhanced robustness. Overall, these results identify non-random features of connectome wiring that allow brains to reconcile extreme sparsity with reliable computation. ### Competing Interest Statement The authors have declared no competing interest. Department for the Economy, https://ror.org/0161w0r98, PhD Scholarship

bioRxiv