flypapers19h 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
flypapers22h 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
flypapers22h 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
flypapers22h 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
flypapers22h 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
flypapers22h 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
flypapers1d ago
📰 "geneslator: an R package for comprehensive gene identifier conversion and annotation"
https://www.biorxiv.org/content/10.64898/2026.03.30.714723v1?rss=1
#DrosophilaMelanogaster
#Drosophila
geneslator: an R package for comprehensive gene identifier conversion and annotation

Motivation: High-throughput sequencing generates large gene lists, making data interpretation challenging. Accurate gene annotation and reliable conversion between identifiers (e.g., Gene symbols, Ensembl GeneIDs, Entrez GeneIDs) are essential for integrating datasets, conducting functional analyses, and enabling cross-species comparisons. Existing tools and databases facilitate annotation but often suffer from inconsistencies, missing mappings, and fragmented workflows, limiting reproducibility and interpretability. Results: To address these limitations, we developed geneslator, an R package that unifies gene identifier conversion, orthologs mapping, and pathway annotation across eight model organisms ( Homo sapiens , Mus musculus , Rattus norvegicus , Drosophila melanogaster , Danio rerio , Saccharomyces cerevisiae , Caenorhabditis elegans , Arabidopsis thaliana ). geneslator provides an up-to-date, precise, and coherent framework that preserves data integrity, enables cross-species analyses, and facilitates robust interpretation of gene function and regulation, outperforming state-of-the-art gene annotation tools. Availability: geneslator is available at https://github.com/knowmics-lab/geneslator ### Competing Interest Statement The authors have declared no competing interest. 2024/2026 Research Plan of University of Catania Pia.ce.ri (IMAGINE project)

bioRxiv
flypapers1d ago
📰 "Inferring circadian phases and quantifying biological desynchrony across single-cell transcriptomes"
https://www.biorxiv.org/content/10.64898/2026.03.30.715278v1?rss=1
#Circadian
#Drosophila
Inferring circadian phases and quantifying biological desynchrony across single-cell transcriptomes

Single-cell RNA sequencing (scRNA-seq) reveals heterogeneity in circadian clock states across individual cells, yet accurately inferring circadian phase and distinguishing biological desynchrony from technical noise remains challenging. Here, we introduce scRitmo, a probabilistic framework that infers single-cell circadian phases from mRNA count data, providing both a point estimate and a posterior uncertainty for each cell. A simulation-calibrated variance decomposition separates the observed phase dispersion into biological and technical components, enabling direct estimation of intercellular desynchrony. We validate scRitmo using deeply sequenced unsynchronized fibroblasts, where inferred transcriptomic phases accurately predict protein-level oscillations of a circadian reporter. Applied to murine scRNA-seq datasets from liver, aorta, and skin, scRitmo outperforms existing methods and reveals cell-type-specific levels of phase coherence. In SABER-FISH time-series data, the method recovers the progressive accumulation of desynchrony following synchronization, and in Drosophila clock neurons it captures cell-type-specific phase shifts and the expected increase in phase dispersion under constant darkness relative to light-dark entrainment. Together, scRitmo provides a principled approach for quantifying circadian (de)synchrony from transcriptomic data, decoupling biological phase variability from measurement noise across tissues, organisms, and experimental conditions. ### Competing Interest Statement The authors have declared no competing interest. Swiss National Science Foundation, 310030B 201267

bioRxiv
flypapers1d ago
📰 "Box H/ACA snoRNP regulates lipid storage through insulin signaling pathway in Drosophila melanogaster"
https://www.biorxiv.org/content/10.64898/2026.03.30.715344v1?rss=1
#DrosophilaMelanogaster
#Metabolism #Drosophila #Larva