Luke W. Silver, Katherine A. Farquharson, Emma Peel, M. Thomas P. Gilbert, Katherine Belov, Hernán E. Morales, Carolyn J. Hogg
{"title":"Temporal Loss of Genome-Wide and Immunogenetic Diversity in a Near-Extinct Parrot","authors":"Luke W. Silver, Katherine A. Farquharson, Emma Peel, M. Thomas P. Gilbert, Katherine Belov, Hernán E. Morales, Carolyn J. Hogg","doi":"10.1111/mec.17746","DOIUrl":"10.1111/mec.17746","url":null,"abstract":"<p>Loss of genetic diversity threatens a species' adaptive potential and long-term resilience. Predicted to be extinct by 2038, the orange-bellied parrot (<i>Neophema chrysogaster</i>) is a critically endangered migratory bird threatened by numerous viral, bacterial and fungal diseases. The species has undergone multiple population crashes, reaching a low of three wild-born females and 13 males in 2016, and is now represented by only a single wild population and individuals in the captive breeding program. Here we used our high-quality long-read reference genome, and contemporary (<i>N</i> = 19) and historical (<i>N</i> = 16) resequenced genomes from as early as 1829, to track the long-term genomic erosion and immunogenetic diversity decline in this species. 62% of genomic diversity was lost between historical (mean autosomal heterozygosity = 0.00149 ± 0.000699 SD) and contemporary (0.00057 ± 0.000026) parrots. A greater number and length of runs of homozygosity in contemporary samples were also observed. A temporal reduction in the number of alleles at Toll-like receptor genes was found (historical average alleles = 5.78 ± 2.73; contemporary = 3.89 ± 2.10), potentially exacerbating disease susceptibility in the contemporary population. Of particular concern is the new threat of avian influenza strain (HPAI) to Australia. We discuss the conservation implications of our findings and propose that hybridisation and synthetic biology may be required to address the catastrophic loss of genetic diversity that has occurred in this species in order to prevent extinction.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 9","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/mec.17746","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katja Susanna Maamela, Eirik Ryvoll Åsheim, Ronan James O'Sullivan, Paul Vincent Debes, Andrew Herbert House, Petra Liljeström, Jenni Maria Prokkola, Petri Toivo Niemelä, Jaakko Erkinaro, Kenyon Brice Mobley, Craig Robert Primmer
{"title":"Food Quality and Life-History Genotype Influence Maturation and Reproductive Traits in Female Atlantic Salmon","authors":"Katja Susanna Maamela, Eirik Ryvoll Åsheim, Ronan James O'Sullivan, Paul Vincent Debes, Andrew Herbert House, Petra Liljeström, Jenni Maria Prokkola, Petri Toivo Niemelä, Jaakko Erkinaro, Kenyon Brice Mobley, Craig Robert Primmer","doi":"10.1111/mec.17735","DOIUrl":"10.1111/mec.17735","url":null,"abstract":"<div>\u0000 \u0000 <p>Age at maturity is an important life-history trait, often showing sex-specific variation, contributing to life-history diversity in many species. Atlantic salmon (\u0000 <i>Salmo salar</i>\u0000 ) are an excellent model system to investigate genetic and environmental factors affecting sex-specific maturation, yet few laboratory studies have focused on females as they mature later than males, on average. Using a 4-year common-garden experiment of Atlantic salmon, we assessed the influence of diet (low-fat vs. control) and <i>vgll3</i> (a candidate gene influencing maturation age) on maturation and related phenotypic traits of female Atlantic salmon derived from two second-generation hatchery populations. We found the early-maturation associated E allele to be additively associated with a higher probability of maturation. Heritability of maturation was estimated to be 0.295, with <i>vgll3</i>'s contribution to phenotypic variance being ~2%. In addition, body condition measured in the spring prior to spawning influenced maturation. Body condition, in turn, was influenced by population and diet. The more northern Oulu population and the low-fat diet were associated with lower body condition compared to the more southern Neva population and the control diet. Moreover, there was an interaction between population and diet on body condition, suggesting that populations may respond differently to nutrient availability. These results broaden our understanding of the processes underlying sex- and population-specific maturation and demonstrate that genes and environment influence age at maturity in a species that displays sex-specific variation in maturation.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 8","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143690392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Océane La Loggia, Diogo F. Antunes, Nadia Aubin-Horth, Barbara Taborsky
{"title":"Social Complexity During Early Development has Long-Term Effects on Neuroplasticity in the Social Decision-Making Network","authors":"Océane La Loggia, Diogo F. Antunes, Nadia Aubin-Horth, Barbara Taborsky","doi":"10.1111/mec.17738","DOIUrl":"10.1111/mec.17738","url":null,"abstract":"<div>\u0000 \u0000 <p>In social species, early social experience shapes the development of appropriate social behaviours during conspecific interactions referred to as social competence. However, the underlying neuronal mechanisms responsible for the acquisition of social competence are largely unknown. A key candidate to influence social competence is neuroplasticity, which functions to restructure neural networks in response to novel experiences or alterations of the environment. One important mediator of this restructuring is the neurotrophin BDNF, which is well conserved among vertebrates. We studied the highly social fish <i>Neolamprologus pulcher</i>, in which the impact of early social experience on social competence has been previously shown. We investigated experimentally how variation in the early social environment impacts markers of neuroplasticity by analysing the relative expression of the <i>bdnf</i> gene and its receptors <i>p75NTR</i> and <i>TrkB</i> across nodes of the social decision-making network. In fish raised in larger groups, <i>bdnf</i> and <i>TrkB</i> were upregulated in the anterior tuberal nucleus, compared to fish raised in smaller groups, while <i>TrkB</i> was downregulated and <i>bdnf</i> was upregulated in the lateral part of the dorsal telencephalon. In the preoptic area (POA), all three genes were upregulated in fish raised in large groups, suggesting that early social experiences might lead to changes of the neuronal connectivity in the POA. Our results highlight the importance of early social experience in programming the constitutive expression of neuroplasticity markers, suggesting that the effects of early social experience on social competence might be due to changes in neuroplasticity.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 9","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elena Karlsen-Ayala, Michelle A Jusino, Matthew E Smith, Romina Gazis
{"title":"Salt Life: Salinity Drives Ectomycorrhizal Community Structure in the Endangered Pine Rocklands.","authors":"Elena Karlsen-Ayala, Michelle A Jusino, Matthew E Smith, Romina Gazis","doi":"10.1111/mec.17737","DOIUrl":"https://doi.org/10.1111/mec.17737","url":null,"abstract":"<p><p>Pinus densa, an endemic and keystone tree in Florida's endangered pine rocklands ecosystem, faces increasing threats from sea level rise and salt intrusion. Ectomycorrhizal (ECM) fungi are critical for pine recruitment and survival, yet their diversity and response to salinity in this ecosystem have been unstudied. We used metabarcoding to survey the naturally occurring ECM fungi on the roots of mature Pinus densa at eight field sites with varying elevations, soil salinities, habitat patch sizes and distances from the ocean, followed by a manipulative greenhouse experiment to assess potential impacts of rising salinity, with four salinity levels on P. densa seedlings in soils that spanned a salinity gradient to evaluate survival and shifts in ECM communities. Results show that salinity stress threatens both P. densa and its ECM symbionts, with ECM fungal richness positively correlated with elevation and negatively correlated with salinity. Habitat patch size, distance from the ocean and soil pH showed no significant effect on richness, and pH was less predictive of community structure. In seedlings, higher salinity was associated with greater mortality and shifts in ECM community composition favouring Rhizopogon species and Pezizales taxa. These findings underscore the susceptibility of ECM fungi to increased salinity, which may disrupt mutualisms critical for coastal resilience. Understanding how salinity affects mutualistic fungi can inform predictions on the vulnerability of other coastal ecosystems to climate change and sea level rise.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17737"},"PeriodicalIF":4.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Danielle M. Adams, Jack G. Rayner, Severine B. S. W. Hex, Gerald S. Wilkinson
{"title":"DNA Methylation Dynamics Reflect Sex and Status Differences in Mortality Rates in a Polygynous Bat","authors":"Danielle M. Adams, Jack G. Rayner, Severine B. S. W. Hex, Gerald S. Wilkinson","doi":"10.1111/mec.17745","DOIUrl":"10.1111/mec.17745","url":null,"abstract":"<p>Males of polygynous mammals often do not live as long as females and, in some cases, exhibit evidence of earlier senescence. Patterns of DNA methylation (DNAm) have recently been used to predict chronological age in mammals. Whether DNAm also changes as a consequence of survival and senescence is largely untested in wild animals. In this study, we estimate mortality rates using recaptures of 2700 greater spear-nosed bats, <i>Phyllostomus hastatus</i>, over 34 years and DNAm profiled for over 300 adult bats. In this species, one male typically controls mating access to a group of unrelated females. Bayesian analysis reveals that mortality risk in males is 1.8 times that of females, and comparison of age-associated differences in DNAm indicates that DNAm changes 1.4 times faster in males than females. Therefore, even though the age of either sex is predicted by a common set of sites, the methylome of males is more dynamic than that of females. Sites associated with sex differences in the rate of DNAm change are sensitive to androgens and enriched on the X chromosome. Sites that exhibit hypermethylation are enriched in promoters of genes involved in the regulation of metabolic processes. Unexpectedly, subordinate males have higher mortality rates than reproductively dominant males and exhibit faster DNAm change than dominants at dozens of sites. Our results reveal that differences in mortality associated with sex and social status are reflected by changes in DNA methylation, providing novel insights into mechanisms of aging and mortality in this and likely other wild animal populations.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 9","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/mec.17745","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Breeding System Derived From Asexual Queen Succession in Termite Colonies From Cold Climate Regions","authors":"Michihiko Takahashi, Takao Konishi, Kiyotaka Yabe, Mamoru Takata, Kenji Matsuura","doi":"10.1111/mec.17724","DOIUrl":"10.1111/mec.17724","url":null,"abstract":"<div>\u0000 \u0000 <p>In social insects, geographic variation is often accompanied not only by physiological changes but also by changes in their social system. In the subterranean termite <i>Reticulitermes speratus</i> that exhibits a sophisticated social system, colonies in subtropical and temperate areas are founded by a pair of primary king and queen derived from sexually produced alates. Some years after colony establishment, many neotenic queens are produced parthenogenetically, which is known as asexual queen succession (AQS). This strategy boosts reproduction without inbreeding. Here we show that subarctic populations of <i>R. speratus</i>, where colonies founded by alates cannot be sustained due to the cold conditions, undergo inbreeding rather than AQS, with colonies headed by numerous neotenic reproductives. Genetic analysis found that most neotenic queens were produced sexually in the subarctic populations, rather than asexually. Rearing experiments using colonies consisting only of nymphs (reproductive-destined individuals) and workers revealed that more nymphs successfully established as neotenic reproductives in the subarctic populations than in temperate populations, and that a higher number of individuals were maintained in the subarctic populations. These results suggest that sexually produced nymphs in subarctic populations are highly predisposed to develop into neotenic reproductives, whereas in temperate populations, their developmental potential is predominantly directed towards becoming alates. This study demonstrates that <i>R. speratus</i> has adjusted to colder climatic zones by changing its sophisticated AQS reproductive system into a secondary strategy to maintain colonies, elucidating the flexible adaptation and acclimation of reproductive systems in social insects.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 8","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana V. Longo, Jaiber J. Solano-Iguaran, Andrés Valenzuela-Sánchez, Mario Alvarado-Rybak, Claudio Azat, Leonardo D. Bacigalupe
{"title":"Blurred Lines Between Determinism and Stochasticity in an Amphibian Phylosymbiosis Under Pathogen Infection","authors":"Ana V. Longo, Jaiber J. Solano-Iguaran, Andrés Valenzuela-Sánchez, Mario Alvarado-Rybak, Claudio Azat, Leonardo D. Bacigalupe","doi":"10.1111/mec.17741","DOIUrl":"10.1111/mec.17741","url":null,"abstract":"<div>\u0000 \u0000 <p>Selection, dispersal and drift jointly contribute to generating variation in microbial composition within and between hosts, habitats and ecosystems. However, we have limited examples of how these processes interact as hosts and their microbes turn over across latitudinal gradients of biodiversity and climate. To bridge this gap, we assembled an extensive dataset of 580 skin bacteriomes from 22 amphibian species distributed across a 10° latitudinal range in Chile. Amphibians are susceptible to the fungal pathogen <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>), which infects their skin, potentially leading to changes in the normal skin microbiome (i.e., dysbiosis). Using comparative methods, accounting for pathogen infection and implementing resampling schemes, we found evidence of phylosymbiosis, characterised by more similar bacterial communities in closely related amphibian species. We also compared how neutral processes affected the assembly of skin bacteria by focusing on two widespread species from our dataset: the Chilean four-eyed frog (<i>Pleurodema thaul</i>) and Darwin's frog (<i>Rhinoderma darwinii</i>). Neutral models revealed that dispersal and chance largely facilitated the occurrence of ~90% of skin bacteria in both species. Deterministic processes (e.g., phylosymbiosis, active recruitment of microbes, microbe–microbe interactions) explained the remaining fraction of the bacteriomes. Amphibian species accounted for 21%–32% of the variance found in non-neutral bacterial taxa, whereas the interaction with <i>Bd</i> carried a weaker but still significant effect. Our findings provide evidence from ectotherms that most of their skin bacteria are subject to dispersal and chance, yet contemporary and historical contingencies leave strong signatures in their microbiomes even at large geographical scales.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 9","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Honghao Liang, Tangcheng Li, Yuanhao Chen, Jingtian Wang, Muhammad Aslam, Huaizhi Qin, Wenkang Fan, Hong Du, Shuh-ji Kao, Senjie Lin
{"title":"Urea Amidolyase as an Enzyme for Urea Utilisation in Phytoplankton: Functional Display in Chlamydomonas reinhardtii","authors":"Honghao Liang, Tangcheng Li, Yuanhao Chen, Jingtian Wang, Muhammad Aslam, Huaizhi Qin, Wenkang Fan, Hong Du, Shuh-ji Kao, Senjie Lin","doi":"10.1111/mec.17734","DOIUrl":"10.1111/mec.17734","url":null,"abstract":"<div>\u0000 \u0000 <p>Urea is an important source of nitrogen for many phytoplankton with the potential to stimulate harmful algal blooms, but the molecular machinery underpinning urea uptake and assimilation by algae is not fully understood. Urease (URE) is commonly regarded as the responsible enzyme, but urea amidolyase (UAL), albeit known to exist, has hardly been studied. Here, the species distribution, expression patterns and functional roles of UAL are examined. We found a widespread occurrence of UAL across six major phytoplankton lineages, along with evidence of a potential URE-independent evolutionary trajectory and lineage-specific losses. Quantitative analyses based on marine planktonic metagenomes and metatranscriptomes revealed that UAL is as prevalent as URE, but exhibits higher expression levels in phytoplankton than in bacteria, suggesting that UAL plays a crucial role in nitrogen nutrition in marine phytoplankton. Furthermore, using the CRISPR/Cas9 genome editing method and \u0000 <i>Chlamydomonas reinhardtii</i>\u0000 as the algal model, we showed that <i>DUR2</i> in UAL is essential for urea utilisation, as its knockout completely abolishes the ability of algae to grow under urea as the sole nitrogen source. This study unveils an unappreciated mechanism in algae for utilising urea as a nutrient, underscores the need to consider both URE and UAL enzyme systems to model urea utilisation by algae and provides a crucial gene (<i>DUR2</i>) as a potential genetic marker for detecting the contribution of UAL to urea utilisation in phytoplankton.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 8","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maximilian Pichler, Simon Creer, Alejandro Martínez, Diego Fontaneto, Willem Renema, Jan-Niklas Macher
{"title":"Metacommunity Theory and Metabarcoding Reveal the Environmental, Spatial and Biotic Drivers of Meiofaunal Communities in Sandy Beaches","authors":"Maximilian Pichler, Simon Creer, Alejandro Martínez, Diego Fontaneto, Willem Renema, Jan-Niklas Macher","doi":"10.1111/mec.17733","DOIUrl":"10.1111/mec.17733","url":null,"abstract":"<p>Understanding the processes that shape community assembly is a critical focus of ecology. Marine benthic meiofauna, microscopic invertebrates inhabiting sediment environments, play important roles in ecosystem functioning but have been largely overlooked in metacommunity studies due to the lack of community data. In this study, we quantify the relative contributions of environmental filtering, spatial processes, and biotic associations in structuring meiofaunal communities. We applied Generalised Dissimilarity Modelling (GDM) and Joint Species Distribution Modelling (JSDM) to an extensive metabarcoding dataset comprising 550 samples collected from sandy beaches along over 650 km of the Dutch and German North Sea coast. Our findings reveal that biotic associations, followed by environmental factors, particularly the distance from the low tide line and sediment grain size, are primary drivers of meiofauna community turnover, highlighting the influence of sharp environmental gradients. Spatial factors indicating dispersal limitations have no major impact on community composition, supporting the assumption that microscopic organisms have strong dispersal capabilities. JSDM results demonstrate that while species sorting is a key driver of community assembly, environmental factors are most important in environmentally distinct (‘extreme’) sites, whereas biotic associations significantly shape community assembly in both environmentally similar and dissimilar habitats, emphasising the need to incorporate species interactions into models of community assembly. By providing insights into the drivers of meiofaunal community structure, our study highlights the importance of environmental gradients and biotic associations in shaping biodiversity patterns and underscores the potential for similar approaches to enhance understanding of other ecosystems with small, highly diverse, but understudied taxa.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"34 8","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/mec.17733","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nora K E Schulz, Danial Asgari, Siqin Liu, Stephanie S L Birnbaum, Alissa M Williams, Arun Prakash, Ann T Tate
{"title":"Resources Modulate Developmental Shifts but Not Infection Tolerance Upon Co-Infection in an Insect System.","authors":"Nora K E Schulz, Danial Asgari, Siqin Liu, Stephanie S L Birnbaum, Alissa M Williams, Arun Prakash, Ann T Tate","doi":"10.1111/mec.17726","DOIUrl":"10.1111/mec.17726","url":null,"abstract":"<p><p>Energetic resources within organisms fuel both parasite growth and immune responses against them, but it is unclear whether energy allocation is sufficient to explain changes in infection outcomes under the threat of multiple parasites. We manipulated diet in flour beetles (Tribolium confusum) infected with two natural parasites and used a combination of transcriptomic and phenotypic assays to investigate the role of resources in shifting metabolic and immune responses after single and co-infection. Our results suggest that relatively benign, single-celled, eukaryotic gregarine parasites alter the within-host energetic environment and, by extension, juvenile development time, in a diet-dependent manner. While they do not affect host resistance to acute bacterial infection, the mRNA-seq results reveal that they stimulate the expression of an alternative set of immune genes and promote damage to the gut, ultimately contributing to reduced survival regardless of diet. Thus, energy allocation is not sufficient to explain the immunological contribution to co-infection outcomes, emphasising the importance of mechanistic insight for predicting the impact of co-infection across levels of biological organisation.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17726"},"PeriodicalIF":4.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}