Biology subjects

Anderson, L.

Publications and source records attributed to Anderson, L..

At least 19 recordsLinked to original sources

bioRxiv2026

Diet-dependent microbiota and diet-independent immunometabolic responses to probiotic supplementation in broiler chickens

Probiotics are widely used in food animal production to support gut health and immune function, but the indicators of probiotic efficacy and the conditions under which they translate to host benefit remain unclear. Microbiota composition is the most accessible data supporting probiotic effects, yet whether compositional change reliably predicts host outcomes is not well understood. We investigated this question in broiler chickens fed two nutritionally similar basal diets, with or without a commercial probiotic. Microbiota composition was profiled across 6 gastrointestinal regions using 16S rRNA sequencing. To assess systemic functional effects, an in vitro assay building on prior observations of elevated circulating immune cell ATP in probiotic-fed animals was developed. In this assay, serum from each treatment group was applied to a chicken T-lymphocyte cell line before ATP quantitation. Basal diet was the primary driver of microbial community structure, with probiotic-induced compositional shifts observed predominantly in one diet context but minimally in the other. Despite this difference, serum from probiotic-supplemented animals increased T-lymphocyte ATP production across both diets, supporting prior findings and revealing a systemic immunometabolic response independent of broad microbiota restructuring. Functional predictions revealed enrichment of pathways related to mevalonate and carbohydrate metabolism in probiotic-supplemented birds within the more responsive diet context, driven largely by Lactobacillaceae family taxa. These findings demonstrate that basal diet modulates the detectability and nature of probiotic effects on the microbiota, but not the physiological host response. This disconnect has implications for how probiotic efficacy is evaluated and for microbiome targeted interventions across species. ImportanceProbiotics are used widely in food animal production to support gut health and immune function, yet predicting which probiotic preparations will produce meaningful effects remains a challenge. Microbiota composition, profiled by 16S rRNA sequencing, is the most accessible measure of probiotic activity, but it captures only one aspect of the host-microbe dynamic. These data demonstrate that probiotic-induced compositional changes vary substantially between basal diets, while the host immunometabolic response is consistent across diets, demonstrating that compositional readouts alone cannot reliably predict host outcomes. The findings have practical implications for how probiotic efficacy is evaluated and inform the broader effort to design microbiome targeted interventions across both veterinary and human contexts.

microbiology↗

bioRxiv2026

Hippocampal and prefrontal contributions to memory-guided navigation depend on task epoch

The hippocampus and medial prefrontal cortex (mPFC) are required for delayed working-memory tasks, but when in the task their engagement becomes necessary remains an open question. We trained mice on a delayed cue-guided T-maze navigation task and used transient optogenetic silencing to test the contribution of the mPFC and hippocampus during distinct task epochs. Surprisingly, silencing during the delay period did not impair performance. In contrast, perturbation during the early phase of the central arm traversal produced robust deficits. Mice made more perseverative choices, slowed their speed and ran farther down the track before turning towards the selected arm. Control experiments showed that these effects could not be explained by the manipulation targeting elapsed time and were rather specific to task phase. These results indicate that hippocampal and prefrontal contributions to memory-guided behavior are not uniform across the trial, but instead depend on task epoch. More broadly, they suggest that the functional engagement of these circuits is gated by behavioral state or context.

neuroscience↗

bioRxiv2026

A layered standards framework for integrating single-cell and spatial omics data into brain cell atlases

The BRAIN Initiative Cell Atlas Network (BICAN) is generating large-scale multimodal datasets to profile cell types in the human, non-human primate, and mouse brain. The diversity of single-cell and spatial transcriptomic and epigenomic assays, combined with varied experimental contexts, multiple data-generating laboratories and distributed infrastructure, poses substantial challenges for data integration and reuse in BICAN. To address this, we implemented a standards framework that enables layered integration of these data into knowledge-ready products for interoperable brain cell atlases. This framework organizes data based on three progressively structured layers. First, we introduced an assay-agnostic modeling layer that unifies the representation of single-cell and spatial omics data using a common set of biological entities and processes assessed by diverse experimental techniques. Second, we implemented harmonized metadata standards that capture key experimental features linked to biospecimen provenance across heterogeneous tissue sources, species, and preparations, supporting integration and validation while minimizing burden on data contributors. Third, we present an extensible representation for data-driven cell type taxonomies that integrates molecular data with annotations, ontology mappings, and evidence. Together, these contributions represent an end-to-end framework that transforms heterogeneous datasets into structured, interoperable resources that support broad community reuse via mapping algorithms, annotation systems, and visualization platforms. This approach links biospecimen provenance with cell-level outputs and embeds these in a standardized taxonomy format, enabling downstream applications such as cross-dataset integration, reference mapping, and knowledge-driven analysis. More broadly, our work demonstrates a generalizable strategy for enabling an efficient data-to-knowledge pipeline in a large-scale consortium setting.

genomics↗

bioRxiv2026

Climate gradients drive the evolution of seed morphology and life history with impacts to seedling fitness in Fraxinus nigra

Background and AimsClimate gradients influence seed morphology, emergence, and early life-history traits with cumulative impacts to individual fitness. For ex situ seed collections, which represent an invaluable repository of potential trait information for species management and conservation, climate data can guide preservation of adaptive variation and inform deployment strategies for restoration. Here we leverage a range-wide ex situ seed collection of critically endangered black ash seeds (Fraxinus nigra) to evaluate how climatic gradients shape variation in morphology and early life-history. MethodsTo test how climate of origin, seed morphology, and early life-history interact to impact first year fitness, high-throughput X-ray imaging and neural network-based segmentation were used to quantify variation in seed morphology for 701 maternal lineages spanning 76 populations across the range of F. nigra. Following this, a subset of seeds were used to establish a common garden experiment and quantify variation in emergence, early life-history transitions, and their cumulative impact to first-year survival and growth. ResultsOn average, differences within-population explained [~]43% of the variability in seed morphology, while among-population differences explained [~]14%. This suggests that substantial genetic variation exists within populations for natural selection to act upon and differences have evolved among populations. Climate associations indicated warmer and drier environments predicted heavier seeds with faster developmental transitions and increased first-year height. Together, climate of origin, seed mass, and timing of developmental transitions best predicted cumulative fitness, with populations from more continental environments exhibiting greater survival and first-year height accumulation on average. ConclusionsOverall, these results highlight the importance of climate of origin, seed traits, and early developmental transitions to first-year fitness in a perennial tree species. This work demonstrates how ex situ collections can be used to identify climatically structured trait variation and guide conservation strategies aimed at maintaining adaptive potential under environmental change.

evolutionary biology↗

bioRxiv2025

Benchmarking of duplex sequencing approaches to reveal somatic mutation landscapes

Detecting somatic mutations in normal tissues is challenging due to sequencing errors and the low allele fractions of post-zygotic variants. Duplex sequencing greatly reduces errors and can detect mutations at any allele fraction, but systematic, cross-platform comparisons are lacking. We present a comprehensive benchmarking of six duplex sequencing technologies used by the SMaHT Network: CODEC, CompDuplex-seq, HiDEF-seq, NanoSeq, ppmSeq, and VISTA-seq. We evaluated their performance using cord blood DNA, a tumor-normal cell line mixture, and homogenates from six human tissues. Each method shows distinct profiles in genomic footprint, sensitivity, and cost. Despite differences in library construction and sequencing platforms, estimates of mutation rates and mutational signatures are highly concordant. Integration with ultra-deep whole-genome sequencing shows that duplex approaches sensitively capture mutations and signatures beyond embryonic or clonally expanded variants. These results provide a foundation for selecting duplex methods and interpreting their data, enabling scalable single-molecule analyses of somatic mutation landscapes. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=101 SRC="FIGDIR/small/692823v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@123b221org.highwire.dtl.DTLVardef@83ba0aorg.highwire.dtl.DTLVardef@2b0ab0org.highwire.dtl.DTLVardef@1cae35e_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

bioRxiv2025

A comprehensive view of somatic mosaicism by single-cell DNA analysis

Single-cell DNA sequencing offers a powerful means of studying somatic mosaicism but requires careful analysis to mitigate DNA amplification-related artifacts. We performed primary template-directed amplification (PTA) and sequencing of 102 nuclei from postmortem lung and colon tissues of a 74-year-old male. Single-cell mutation burdens and spectra were validated by duplex sequencing and revealed heterogeneity across organs and cells, including signatures of APOBEC activity and tobacco exposure. Cells from both tissues exhibited chromosomal aneuploidies, loss of chromosome Y, and chromosomal rearrangements including rearrangements of the T-cell receptor loci indicative of T-cells. Shared embryonic mutations between cells enabled reconstruction of cellular ancestries from the zygote, which were validated by bulk sequencing. Collectively, we demonstrate a comprehensive approach for single-cell genomics that yields an expansive view of diverse somatic mutation types from development through aging across diverse tissues--insights that are obscured in bulk sequencing and only partially captured by other single-cell methods.

genomics↗

bioRxiv2025

Comprehensive benchmarking of somatic single-nucleotide variant and indel detection at ultra-low allele fractions using short- and long-read data

Mosaic mutations in normal tissues occur at low variant allele fractions (VAFs), complicating detection. To benchmark strategies, the SMaHT Network created a cell-line mixture (1:49) and produced ultra-deep whole-genome sequencing using short and long reads (five centers, 180-500x each). We assembled a reference of 44,008 mosaic SNVs and 2,059 Indels, cross-validation between platforms to expose limits of short-read analysis. We also partitioned the genome by mappability to examine the impact of genomic context, added a negative reference set, and accounted for culture-derived mutations. When seven institutions applied eleven algorithms to mixture data, call sets were largely discordant across tools and replicates, partly reflecting stochastic presence of low-VAF mutations in biological replicants. For >2% VAF SNVs, sensitivity and precision approached [~]80% at [≥]300x, with little gain from additional sequencing. This work provides a comprehensive framework for reliable detection of low-VAF mutations in non-cancer tissues and a valuable resource for the community.

bioinformatics↗

bioRxiv2025

CDK4/6 inhibition induces a DNA damage-independent senescence-associated secretory phenotype driven by delayed activation of NF-κB

Cellular senescence consists of regulated cell phenotypes associated with permanent exit from the cell cycle in response to stressors such as genomic instability. The consequences of senescence go beyond individual cells due to the senescence associated secretory phenotype (SASP), which can induce inflammation in neighboring cells. Some cancers respond to CDK4/6 inhibitors (CDK4/6i)--a family of targeted therapies that inhibit proliferation--with a senescence-like phenotype in the absence of DNA damage. We asked how the SASP and the transcriptional regulatory profile triggered by CDK4/6i-driven arrest compares to the canonical NF-{kappa}B-regulated SASP triggered by DNA damage. We profiled the temporal dynamics of transcriptional regulation in response to the CDK4/6i, palbociclib, and the DNA damaging agent, doxorubicin. We found that, although upregulation of NF-{kappa}B driven-SASP genes is shared across both drugs, it is delayed in CDK4/6i. This coincides with slower enhancer activation and epigenetic changes. Interestingly, ATM/ATR inhibition does not affect CDK4/6i-induced NF-{kappa}B nuclear localization, pointing to an alternative mechanism driving NF-{kappa}B activity in the absence of DNA damage. Inhibiting NF-{kappa}B suppresses the expression of shared SASP genes without reversing stable arrest. This points to SASP manipulation as a potential therapeutic strategy, and resolves an ongoing controversy about the nature of cell cycle arrest-driven SASP.

cancer biology↗

bioRxiv2025

Paranemic cohesion of DNA molecules in different counter ions at room and physiological temperatures

Isothermal assembly allows the construction of DNA nanostructures at constant moderate temperatures. Further, assembly of DNA nanostructures in different counter ions expands their utility in various applications. In this work, we demonstrate the isothermal assembly of paranemic crossover (PX) DNA motifs in magnesium (Mg2+), calcium (Ca2+) and strontium (Sr2+) at 20 {degrees}C and 37 {degrees}C. Further, we study how differences in design affect the assembly of 4-stranded and 2-stranded PX molecules.

synthetic biology↗

bioRxiv2025

Controlled reassociation of multistranded, polycrossover DNA molecules into double helices

Shape-changing DNA nanostructures have found applications in biosensing, drug delivery, cell modulation and data storage. A key aspect of this reconfiguration is the interaction of DNA nanostructures with other biomolecules or chemical stimuli such as pH and ionic conditions. Sequence-based nanostructure reconfiguration is largely achieved by strand displacement which is based on single stranded toeholds. In this work, we use sequence and temperature-controlled reassociation of one type of a DNA nanostructure into another structure. We demonstrate this strategy using the paranemic crossover (PX) DNA, a four-stranded structure with two adjacent double helical domains connected by six strand crossovers. In the presence of an anti-PX structure that is composed of strands that are each complementary to those in PX DNA, the structures reassociate at specific temperatures to form duplexes. Using the denaturing agent formamide, we decreased the temperature required for this reassociation. We extend the strategy to other polycrossover DNA molecules such as a double crossover motif (2 crossovers) and a juxtaposed DNA motif (4 crossovers), showing controlled reassociation of different DNA motifs into duplexes. Our study highlights the potential for DNA motifs to function as switchable molecular systems, offering new insights for responsive DNA-based materials and devices.

synthetic biology↗

bioRxiv2025

Slow synaptic plasticity from the hippocampus underlies gradual mapping and fragmentation of novel spaces by grid cells

Animals construct internal "cognitive maps" of the world during navigation in spatial and non-spatial domains, with grid cells in the medial entorhinal cortex (MEC) playing a key role. This requires associating internal position estimates with external cues to reduce spatial uncertainty over time. However, how grid cell representations evolve in novel spaces to support map formation is unclear. To address this question, we longitudinally imaged calcium dynamics of grid cells over 10 days as mice learn operant tasks in novel virtual linear tracks. We observe that spatial tuning of grid cells is present immediately in novel tracks but evolves as a significant fraction of spatial fields shift backward on a run-by-run basis, within and across days. Backward shifts are more prevalent and persistent in successful learners. The fields gradually stabilize across days, anchored by landmarks, suggesting slow plasticity. The backward shifts partially reset daily, reflecting a slower consolidation timescale. While individual fields of a cell shift differentially, co-active fields of co-modular grid cells shift together, indicating their coupled dynamics on the same two-dimensional torus. Spatial learning leads to systematic changes and stabilization of their population phase trajectory, including lateral shift, rotation, and phase resets at landmarks, forming a landmark-fragmented representation for the environment. Next, we build an entorhinal-hippocampal model that provides a mechanistic explanation of the diverse phenomena - grid field shifts, increasing fidelity, and fragmentation of the spatial map - and predicts slow Hebbian plasticity in the hippocampus-to-entorhinal pathway. Supporting this, electrophysiology demonstrates that learning-performance-correlated weakening of local inhibition facilitates potentiation of indirect hippocampal inputs to superficial MEC. Together, our study provides multifaceted evidence of slow hippocampus-to-MEC plasticity, elucidating the formation of stable and fragmented cognitive maps that combine internal and cue-driven positional estimates in rich environments during learning. This mechanism may extend to broader memory processes involving this circuit.

neuroscience↗

bioRxiv2025

The yEvo Mutation Browser: Enhancing student understanding of experimental evolution and genomics through interactive data visualization

Experimental evolution is a powerful method for studying the relationship between genotype and phenotype by observing how populations genetically adapt to controlled selective pressures. In educational settings, this approach also offers a dynamic way for students to engage with molecular genetics. One such educational effort, known as "yEvo" (yeast evolution), introduces experimental evolution into high school classrooms, allowing students to evolve the bakers yeast Saccharomyces cerevisiae under various stressors and investigate the resulting genetic changes. While the hands-on experiments have been successful in fostering student interest and understanding of evolution, the downstream data analysis (interpreting whole-genome sequencing results of evolved yeast compared to the ancestor) remains a challenge. Students often struggle to grasp the significance of their mutated genes and lack the broader context to determine which mutations are most phenotypically relevant. To address these issues, we developed the yEvo Mutation Browser, an intuitive web tool designed to assist students and researchers alike in visualizing and contextualizing genome sequencing data. Developed using R Shiny, this tool features an interactive chromosome map displaying mutated genes, graphs categorizing mutation types, a gene viewer illustrating specific mutation sites within genes, and a protein view that maps specific mutations onto protein structures. The app also features an option for non-yEvo-affiliated users to upload their own experimental evolution or genetic screen datasets and compare them with all yEvo data collected since 2018. The yEvo Mutation Browser streamlines data interpretation, helping students understand how organisms employ diverse genetic strategies to adapt to environmental stress. In the future, this framework could be adapted for use with other model organisms, offering a valuable resource for both genetics research and education. SignificanceBringing novel research into the classroom can transform how students learn science. The yEvo project engages high school students in experimental evolution, enabling them to witness natural selection in action and connect genetic mutations to evolutionary outcomes. By providing an accessible web-based tool, the "yEvo Mutation Browser," this work lowers barriers to interpreting genome sequencing data, allowing students, teachers, and researchers alike to explore how yeast populations adapt to diverse stress conditions. This resource not only strengthens STEM education by making cutting-edge genetics more approachable, but also builds a shared dataset that enriches the broader yeast genetics community.

scientific communication and education↗

bioRxiv2024

Alternating hemiplegia of childhood associated mutations in Atp1a3 reveal diverse neurological alterations in mice.

Pathogenic variants in the neuronal Na+/K+ ATPase transmembrane ion transporter (ATP1A3) cause a spectrum of neurological disorders including alternating hemiplegia of childhood (AHC). The most common de novo pathogenic variants in AHC are p.D801N ([~]40% of patients) and p.E815K ([~]25% of patients), which lead to early mortality by spontaneous death in mice. Nevertheless, knowledge of the development of clinically relevant neurological phenotypes without the obstacle of premature death, is critical for the identification of pathophysiological mechanisms and ultimately, for the testing of therapeutic strategies in disease models. Here, we used hybrid vigor attempting to mitigate the fragility of AHC mice and then, performed behavioral, electrophysiological, biochemical, and molecular testing to comparatively analyze mice that carry either of two most common AHC patient observed variants in the Atp1a3 gene. Collectively, our data reveal the presence but also the differential impact of the p.D801N and p.E815K variants on disease relevant alterations such as spontaneous and stress-induced paroxysmal episodes, motor function, behavioral and neurophysiological activity, and neuroinflammation. Our alternate AHC mouse models with their phenotypic deficits open novel avenues for the investigation of disease biology and therapeutic testing for ATP1A3 research.

neuroscience↗

bioRxiv2024

Characteristics of early career health researchers and experiences of burnout during the COVID-19 pandemic in Canada

IntroductionThe COVID-19 pandemic disrupted research globally. How it impacted Canadian early-career health researchers (ECHRs) remains unclear. We administered a survey to understand the composition of ECHRs in Canada, their job experiences, and experiences of burnout during the COVID-19 pandemic. MethodsA cross-sectional survey was conducted in May 2023 of Canadian ECHRs defined as within 7 years of their first independent research position. Quantitative analyses included a description of respondents by research pillar, socio-demographic and workplace characteristics, and the prevalence of burnout, disengagement or exhaustion. Sample characteristics were compared to national data on ECHRs from a Canadian funding agency. Thematic analysis of free-text responses was also conducted. ResultsA total of 225 respondents met the eligibility criteria. Most respondents were assistant professors and characteristics of our sample were like the national data. The COVID-19 pandemic posed many challenges to student recruitment, and emotional support of students, with over half of the respondents reporting a moderate to significant decline in mental health compared to pre-pandemic. A significant proportion of respondents were experiencing high burnout (62%, 95%CI:56-67%), exhaustion (64%, 95%CI: 57-70%) or disengagement (91%, 95%CI: 87-95%). Thematic analysis identified three themes: ongoing benefits/problems preceding the pandemic, unintended outcomes of strategies to manage/prevent/contain COVID-19, and reasons to stay in their current position. ConclusionsOur survey revealed that Canadian ECHRs reported many diverse challenges during the COVID-19 pandemic and high burnout, putting the sustainability of this workforce at risk. Improved systems are needed to understand the long-term impacts and support the future of the Canadian health research ecosystem.

scientific communication and education↗

bioRxiv2023

Nature Forest Reserves in Tanzania and their importance for conservation

Since 1997 Tanzania has undertaken a process to identify and declare a network of Nature Forest Reserves (NFRs) with high biodiversity values, mainly from within its existing portfolio of national Forest Reserves, but with some new extensions. In recent years this expansion has accelerated, with ten NFRs declared since 2015. The current network of 19 existing NFRs covered 918,212 hectares by the end of 2020 (with an additional three reserves covering 34,862 hectares in the process of being declared). The coverage by NFRs of Tanzanian habitat types has increased to include the main forest types, wet, seasonal, and dry, and includes wetlands and grasslands. This has led to more than a doubling of the coverage of species ranges of vertebrates by the NFR network. Declared and proposed reserves now contain at least 178 of Tanzanias 242 endemic vertebrate species, of which over 50% are threatened with extinction, and 553 Tanzanian endemic plant taxa (species, subspecies, and varieties), of which 61.3% are threatened. NFRs also support 41 single site endemic vertebrate species and 76 single site endemic plant taxa. Time series data show that NFR management effectiveness is increasing, especially where donor funds are available. Tourism, diversified revenue generation and investment schemes are required to create a network of economically self-sustaining NFRs able to conserve critical biodiversity values. Improved management and investment have reduced some threats in recent years, but ongoing challenges include illegal logging, charcoal production, firewood, pole cutting, hunting, fire, wildlife trade, and the unpredictable impacts of climate change.

ecology↗

bioRxiv2022

ROCK2 Knockout Improves Proliferation Rate in a Cellular Model of Down Syndrome

In a cellular model of Down Syndrome, hTERT immortalized RPE-1 (human retinal pigment epithelial-1) cells carrying an extra copy of chromosome 21 exhibit reduced fitness, in part, as an increase in doubling time (or a reduction in cell proliferation rate) in culture. ROCK2 (Rho associated coiled-coil containing kinase 2) was identified in a whole genome CRISPR knockout (KO) screen designed to identify genes and pathways that could be therapeutically targeted to improve cell proliferation (Replogle JM, et al. manuscript in preparation). ROCK2 KO cell lines of both RPE-1 euploid and trisomy 21 aneuploid cells were created using CRISPR. Trisomy 21 ROCK2 KO cell lines showed a modest increase in cell proliferation rate compared to the parental aneuploid cells, similar to the relative effect that ROCK2 knockout had in the whole genome CRISPR screen. Euploid ROCK2 KO cell lines showed no difference in growth rate vs their ROCK2 expressing counterparts. Changes in doubling time in response to two pharmaceutical ROCK inhibitors, Fasudil and Y27632, also showed the same modest increase in cell proliferation rate in the trisomy 21 cells. The actin cytoskeleton, a target of ROCK2 regulation, exhibited long stress fibers that aligned across multiple contiguous cells in confluent trisomy 21 ROCK2 KO cells compared to the disorganized stress fibers of the parental trisomy 21 cells with normal ROCK2 expression.

cell biology↗

bioRxiv2021

Bacteria but not fungi communities differ among perennial grassland ecotypic rhizosphere under abiotic environmental stress

Environmental change, especially frequent droughts, is predicted to detrimentally impact the North American perennial grasslands. Consistent dry spells will affect plant communities as well as their associated rhizobiomes, possibly altering the plant host performance under environmental stress. Therefore, there is a need to understand the impact of drought on the rhizobiome, and how the rhizobiome may modulate host performance and ameliorate its response to drought stress. In this study, we analyzed bacterial and fungal communities in the rhizospheres of three ecotypes (dry, mesic, and wet) of a dominant prairie grass, Andropogon gerardii. The ecotypes were established in 2010 in a common garden design and grown for a decade under persistent dry conditions at the arid margin of the species range in Colby Kansas. The experiment aimed to answer whether and to what extent do the different ecotypes maintain or recruit distinct rhizobiomes after ten years in an arid climate. In order to answer this question, we screened the bacterial and fungal rhizobiome profiles of the ecotypes under the arid conditions of western KS as a surrogate for future climate environmental stress using 16S rRNA and ITS2 metabarcoding sequencing. Under these conditions, bacterial communities differed compositionally among the A. gerardii ecotypes, whereas the fungal communities did not. The ecotypes were instrumental in driving the differences among bacterial rhizobiomes, as the ecotypes maintained distinct bacterial rhizobiomes even after ten years at the edge of the host species range. This study will aid us to optimize plant productivity through the use of different ecotypes under future abiotic environmental stress, especially drought.

bioinformatics↗

bioRxiv2021

Mitonuclear interactions affect locomotor activity and sleep in Drosophila melanogaster

Mitochondria are organelles that produce cellular energy in the form of ATP through oxidative phosphorylation, and this primary function is conserved between many taxa. Locomotion is a trait that is highly reliant on metabolic function and expected to be greatly affected by disruptions to mitochondrial performance. To this end, we aimed to examine how activity and sleep vary between Drosophila melanogaster strains with different geographic origins, how these patterns are affected by mitochondrial DNA (mtDNA) variation, and how breaking up co-evolved mito-nuclear gene combinations affect the studied activity traits. The results demonstrate that Drosophila strains from different locations differ in sleep and activity, and the extent of variation differs between sexes, females in general being more active. By comparing activity and sleep of mtDNA variants introgressed onto a common nuclear background in cytoplasmic hybrid (cybrid) strains, we establish that mtDNA variation affects both traits, sex specifically. Furthermore, by using previously published mtDNA copy number data, we detected a positive correlation between mtDNA copy number and the activity levels of the cybrid flies. Altogether, our study shows that both mtDNA variation and mitonuclear interactions affect activity and sleep patterns, highlighting the important role that both genomes play on life-history trait evolution.

genetics↗