Molecular Ecology最新文献

{"title":"Genomics of Speciation","authors":"Ji Wang, Zhiqin Long, Daniel Ortiz-Barrientos, Samridhi Chaturvedi, Mitch Cruzan, Brent Emerson, Deyan Ge, Tatiana Giraud, Shotaro Hirase, Kaichi Huang, Kotaro Kagawa, Haiwei Luo, Yanhua Qu, Suhua Shi, Clement K. M. Tsui, John Welch, Loren H. Rieseberg","doi":"10.1111/mec.70566","DOIUrl":"10.1111/mec.70566","url":null,"abstract":"<p>Advances in genomics and in our ability to analyse and interpret genomic data have revolutionized our understanding of how new species arise (Bock et al. <span>2023</span>; Seehausen et al. <span>2014</span>). These developments have also democratized the study of speciation by enabling research on long-lived organisms, those difficult to culture in laboratory or greenhouse settings, or those that are challenging to mate (Delmore et al. <span>2024</span>). Here, we first describe major insights into speciation enabled by genomic approaches, many of which are further illuminated by the 51 papers published in this special issue. We then discuss unresolved questions raised in the special issue. Lastly, we identify promising areas for future research, considering both notable gaps in our understanding of speciation and emerging technological and analytical tools that will help us fill some of these gaps and open new avenues of inquiry.</p><p>In this section, we discuss changes in our thinking about speciation over the past three decades that have been stimulated, in part, by results from genomic studies (Figure 1). In some instances, genomic results have helped resolve debates that began with the publication of <i>The Origin of Species</i> (Darwin <span>1859</span>), whereas other questions were prompted by the availability of the genomic data itself. In most cases, it has been the combination of genomic data with results from other kinds of studies—such as theoretical, field, experimental evolution, and comparative studies—that has provided decisive answers.</p><p>As illustrated by this special issue, we are in the golden age of speciation genomics, where every year new and exciting discoveries are being reported. Many of these discoveries stem from the application of high-throughput sequencing approaches to non-model organisms, permitting insights from groups that are biologically interesting, but experimentally intractable. However, of equal importance has been the development of new analytical approaches, enabling inferences about speciation processes at spatial (both geographically and along genomes) and temporal scales that were unthinkable at the turn of the century. We also now have relevant genomic results from many different taxa, stimulating broad generalizations about speciation, such as those that were discussed earlier in this perspective, and facilitating the search for similarities and differences in speciation patterns across the tree of life (Wang, Mank, et al. <span>2025</span>). An emergent theme is that speciation is driven by natural selection, with other processes playing subordinate roles, affirming that Darwin had it right all along (Darwin <span>1859</span>).</p><p>L.H.R. wrote the manuscript. J.W. and Z.L. developed the figures and reviewed and edited the manuscript. All other authors contributed to the editing and reviewing of the manuscript.</p><p>Studies by the Rieseberg lab on the genomics of speciation have been sup","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/mec.70566","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101486","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":"Introgression Shapes Genetic Variation Associated With Humid Environments in Aedes aegypti Mosquitoes From Saudi Arabia","authors":"Abadi M. Mashlawi,&nbsp;Dario Balcazar,&nbsp;Sara A. Abuelmaali,&nbsp;Mohammed Fahad Albeshr,&nbsp;Mohamed F. Sallam,&nbsp;Hesham M. Al-Mekhlafi,&nbsp;Catherine Walton,&nbsp;Andrea Gloria-Soria","doi":"10.1111/mec.70575","DOIUrl":"10.1111/mec.70575","url":null,"abstract":"<p>Introgression between genetically distinct populations generates variation that may promote adaptation to diverse environmental conditions. In the mosquito <i>Aedes aegypti</i>, the forest-associated subspecies <i>Aedes aegypti formosus</i> (Aaf) underwent a domestication process approximately 5000 years ago, giving rise to the globally invasive, human-associated arbovirus vector <i>Aedes aegypti aegypti</i> (Aaa). Despite extensive human-mediated transport, the two subspecies remain largely distinct, with admixture documented mainly in coastal Africa and Saudi Arabia. We examined Saudi Arabian <i>Ae. aegypti</i> across climatically contrasting regions – the humid south and arid west- using a Saudi Arabian dataset (11,939 SNPs) to examine within-country genetic and environmental variation and a global dataset (13,455 SNPs) to assess ancestry and admixture in a worldwide context. Genomic analyses revealed strong west–south differentiation, with Jazan Highland showing admixture between subspecies and the highest proportion of Aaf ancestry. Multiple pulses of gene flow into and within southern Saudi Arabia suggest Aaf populations act as a reservoir of genetic variation. Genome-wide scans identified a candidate region associated with the humidity gradient, harbouring an elongase of very long-chain fatty acids (AAEL024147), essential for cuticle production and minimizing water loss. Because the Saudi Arabian genetic background is predominantly the arid-adapted subspecies Aaa, the presence of Aaf ancestry at this locus may reflect localized introgression with adaptive relevance under an increasingly humid environment. Our findings highlight how secondary contact between divergent lineages may contribute to local adaptation in <i>Ae. aegypti</i>, with implications for predicting responses to environmental change.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13635610/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101427","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":"Spatial Disparities Among Oceanic Protists' Ecological Dynamics in the Bay of Bengal","authors":"Laxman Pujari,&nbsp;Sujata Nilajkar,&nbsp;Jun Sun","doi":"10.1111/mec.70572","DOIUrl":"10.1111/mec.70572","url":null,"abstract":"<div>\u0000 \u0000 <p>Protists are the dominant eukaryotes in the ocean biosphere, and oceanic protists (OP) serve as a critical link among bacterial production, primary producers, and higher trophic levels. This study examined the community structure and vertical organization of OP assemblages in the Bay of Bengal (BoB) across three depth layers: surface (5 m), mid-depth (150 m), and bottom (300 m). Multivariate ordination, diversity metrics, and network analyses consistently demonstrated that vertical depth is the primary factor structuring OP communities, whereas regional (north–south) variability was minimal. Alpha diversity analyses showed that Shannon and Simpson diversity differed significantly among depth layers, whereas Chao1 richness did not, indicating that depth-related changes were reflected mainly in community evenness and dominance structure rather than estimated richness. Beta diversity analyses (PERMANOVA) further confirmed strong depth-wise separation of communities and no significant regional effect. Surface OP communities were characterized mainly by Syndiniales, with additional contributions from Polycystinea, Dinophyceae, Diatomea, Intramacronucleata, and Prymnesiales, whereas mid-depth and bottom assemblages showed stronger contributions from Polycystinea and Diplonemea. Network analyses revealed depth-specific differences in modularity, connectivity, and robustness, with the mid-depth network showing the highest modularity and the bottom network showing the strongest local connectivity but greater sensitivity to node removal. RDA highlighted clear depth-related associations between OP communities and environmental gradients, with surface assemblages aligned with temperature and Chl-<i>a</i>, and deeper assemblages associated with salinity, phosphate, and silicic acid gradients. Overall, these findings reveal a vertically stratified organization of OP communities in the BoB, associated with depth-dependent environmental gradients and potential biotic associations within a stratified tropical ocean system.</p>\u0000 </div>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101527","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}

{"title":"Problems With GO Enrichment as an Endpoint for Ecological Omics Interpretation","authors":"Ehsan Pashay Ahi,&nbsp;Nidal Karagic,&nbsp;Spiros Papakostas","doi":"10.1111/mec.70570","DOIUrl":"10.1111/mec.70570","url":null,"abstract":"<p>Gene Ontology (GO) enrichment analysis has been widely adopted for interpretating omics data, including in ecological research. Although valuable for summarizing large gene lists into functional categories, it is often treated as the final interpretive step. In ecological omics, where functional annotations are frequently incomplete and experimental validation is often difficult, this reliance can lead to repetitive, generic conclusions that lack environmental and mechanistic specificity. Although previous literature has addressed the statistical and annotation-related limitations of GO enrichment, its role in shaping the broader interpretive process has received less critical attention. Here, we highlight a conceptual weakness: the treatment of enriched GO terms as definitive biological insight. We focus particularly on ecological studies of non-model organisms in complex, and heterogeneous environments. We discuss complementary strategies, including co-expression network analysis, integration with environmental metadata, phylogenetically informed annotation, and AI-assisted functional inference. To promote more context-sensitive interpretation, we introduce the concept of <i>GO-Deep</i>, which frames GO enrichment as a starting point for integrative, multilayered functional insight. By reframing GO enrichment as an entry point rather than a conclusion, ecological omics can move toward more mechanistically informative and environmentally grounded interpretations of high-throughput data.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633471/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101538","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":"Mosaic Accumulation of Somatic Genetic Variation and Estimates of Age in the Long-Lived Reef-Building Coral Acropora palmata","authors":"Trinity Conn,&nbsp;Jessie Renton,&nbsp;Valerie F. Chamberland,&nbsp;Zoe Dellaert,&nbsp;Thorsten B. H. Reusch,&nbsp;Benjamin Werner,&nbsp;Iliana B. Baums","doi":"10.1111/mec.70580","DOIUrl":"10.1111/mec.70580","url":null,"abstract":"<p>Somatic genetic variation (SoGV) accumulates during an organism's lifetime and is traditionally viewed as detrimental rather than adaptive due to links with cancer and senescence. However, in modular organisms like corals, deleterious mutations can be purged at the cellular or polyp level, while adaptive mutations may rise in frequency as polyps create genetically distinct modules. Quantifying the somatic genetic landscape in corals is necessary to understand the role these mutations may have in coral and clonal animal development and evolution. Here, we catalogue somatic genetic variation in eight <i>Acropora palmata</i> colonies from Curaçao. Whole genomes were sequenced (70–100× depth) to document mutation variant allele frequency shifts as genets age. Large numbers of SoGVs were observed in six- to ten-year-old colonies, and inferred mutation rates were used to age a genet of uncertain age to almost a century old. Mutations were not fixed at the polyp or branch levels, i.e., they always displayed frequencies &lt; 0.5 as expected at mutating homozygous sites. However, their allele frequencies followed a power-law distribution, similar to aging human tissues. No signs of positive selection were found; instead SoGVs were under purifying selection. In one colony, mutations in 28 samples from along a branch were analysed using a SNP microarray. Contrary to expectations, genetic and physical distances were unrelated. Along with an observed lack of fixation this pattern may be explained by a large stem cell population, the de-differentiation or dormancy of stem cells, the contribution of strong purifying selection, or a combination of the previously mentioned. Our findings provide a neutral framework against which to test for module-level selection of genetic variation in corals, explore the relationship between physical and genetic distance within a colony, and apply a somatic genetic clock to colonies of <i>Acropora palmata</i>. This work provides fundamental insights into the landscape of somatic mutations in reef-building coral, highlighting the importance of studying somatic genetic variation as they may contribute to genetic diversity and adaptability in colonial animals.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101473","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":"Natural Variation in Drosophila melanogaster Clock PolyQ Length: Geographic Gradients and Functional Properties","authors":"Maya Yair,&nbsp;Bettina Fishman,&nbsp;Martin Kapun,&nbsp;Eran Tauber","doi":"10.1111/mec.70554","DOIUrl":"10.1111/mec.70554","url":null,"abstract":"<p>Natural variation in circadian clock genes provides a powerful framework for understanding how organisms respond to environmental heterogeneity. The <i>Clock</i> (<i>Clk</i>) gene encodes a core transcriptional regulator of circadian rhythms and contains a polymorphic polyglutamine (polyQ) tract whose evolutionary significance remains unclear. Here, we integrate population genomic, behavioural, and molecular analyses to investigate the functional and geographic patterns of <i>Clk</i> polyQ variation in <i>Drosophila melanogaster</i>. Using data from 127 European populations, we identify 11 <i>Clk</i> polyQ alleles and find that their frequencies are geographically structured, most consistently along an east–west gradient: the Q25 and Q27 alleles show robust clines in longitude and in a bioclimatic axis of continentality, whereas latitudinal and altitudinal trends are weaker. Behavioural assays of near-isogenic lines revealed that polyQ length modulates circadian function under thermal challenge: most alleles maintained stable free-running periods across temperatures, whereas the intermediate-length Q25 allele showed the strongest, though modest, temperature sensitivity. Circadian phase showed pronounced allele-specific sensitivity to elevated temperature in laboratory assays, although phase variation did not display a consistent relationship with geographic variables. At the molecular level, luciferase reporter assays showed that longer polyQ alleles exhibited higher transcriptional activity, linking polyQ length to CLK-mediated gene expression. Together, these results demonstrate that natural variation in <i>Clk</i> polyQ length has measurable functional consequences for circadian regulation and is geographically structured in patterns consistent with underlying climatic variation, highlighting the potential for low-complexity regions to modulate clock function in a context-dependent manner across environmental gradients.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633423/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101588","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":"Spatial and Ecological Drivers of Diversification in the World's Southernmost Gecko.","authors":"Kevin I Sánchez, Perry Lee Wood, Jack W Sites, Melisa Olave, Luciano J Avila, Mariana Morando","doi":"10.1111/mec.70581","DOIUrl":"https://doi.org/10.1111/mec.70581","url":null,"abstract":"<p><p>Understanding the mechanisms driving genetic differentiation-and ultimately, speciation-is central to evolutionary biology, particularly in widespread species inhabiting environmentally complex landscapes. Homonota darwinii, a member of the H. whitii group, is the southernmost gecko in the world, distributed across the Patagonian Steppe-a vast, heterogeneous landscape with a complex geoclimatic history. This system offers an opportunity to assess the relative roles of geographic distance, environmental variation, and landscape resistance in diversification. We present a comprehensive dataset of > 700 geckos sampled over 20 years across > 1,000,000 km² of southern South America. Using phylogeographic, landscape genomics and coalescent approaches, we examined patterns of population divergence and connectivity. Genomic data revealed geographically consistent groups and admixture in transitional zones. We identified three putative species-level lineages corresponding to regional phylogeographic breaks shared by other taxa. Landscape genomic analyses indicated that isolation-by-environment (IBE), particularly climatic gradients related to aridity, temperature, and seasonality, was the primary driver of genetic divergence. We also identified genomic variants associated with local adaptation. Our results suggest that H. darwinii expanded into the Patagonian Steppe during the Pliocene, with persistence facilitated by adaptations to arid conditions. Within the H. whitii group, we found evidence supporting a hybrid speciation model for Homonota williamsii, involving roughly equal genomic contributions from two H. darwinii genetic groups. This study highlights the interplay of spatial, ecological and historical factors in shaping genetic structure and adaptation. It also provides a framework for taxonomic and conservation initiatives, especially given prior projections of climate-driven population decline in H. darwinii.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":"e70581"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149147077","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}

{"title":"Bottlenecked but Booming: Strong Inbreeding in a Highly Invasive Freshwater Mussel.","authors":"Antti Miettinen, Emma Sejrskild Jensen, Johanne Gottenborg, Silas Tanderup, Aja Noersgaard Buur Tengstedt, Carol A Stepien, Michael M Hansen","doi":"10.1111/mec.70584","DOIUrl":"10.1111/mec.70584","url":null,"abstract":"<p><p>The 'genetic paradox of invasions' refers to successful invasive populations originating from low founder numbers. Theory predicts that such invaders should exhibit reduced genetic diversity and increased inbreeding, which should restrict their evolutionary potential and often lead to inbreeding depression. Here, we provide evidence for an invader succeeding against these odds by demonstrating strikingly strong inbreeding in a highly successful, invasive freshwater mussel. Using whole-genome resequencing data, we show that zebra mussels (Dreissena polymorpha) from thriving invasive populations carry numerous and long runs of homozygosity (ROH) in their genomes, reflecting severe, sequential founder events followed by inbreeding during the invasion process. Additionally, predicted genetic load (accumulation of deleterious mutations) is correlated with inbreeding levels: more inbred invasive populations exhibit lower masked (i.e., heterozygous) but higher realised (i.e., homozygous) load compared to less inbred populations. These genomic consequences of inbreeding would be expected to decrease the fitness of invasives, but here have not prevented their success. Our study thus challenges conventional expectations that inbreeding and high numbers of putatively deleterious alleles should limit biological invasion success. This research provides a compelling example of an invader that defies genetic expectations, and is therefore broadly relevant for understanding invasion success and dynamics across taxa.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":"e70584"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13653133/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149147388","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":"Host-Associated Differentiation in a Parasitoid Wasp Connected to Venom-Related but Not Chemosensory Genes.","authors":"Xuyue Yang, Marco Fracassetti, Tanja Slotte, Christopher W Wheat, Peter A Hambäck","doi":"10.1111/mec.70589","DOIUrl":"10.1111/mec.70589","url":null,"abstract":"<p><p>The mechanisms driving the megadiversity of parasitic wasps remain a central question in evolutionary ecology. To investigate the genomic architecture underlying host-associated differentiation in parasitic wasps, we generated a de novo genome assembly and performed whole-genome re-sequencing of 17 populations of the parasitoid wasp Asecodes parviclava (Eulophidae) across a latitudinal gradient and multiple Galerucella host species. Despite panmixia in host populations, we identified three genetically differentiated wasp lineages, with the most profound divergence separating Galerucella tenella-associated wasps from other populations. Locus-specific scans revealed that selection acts highly asymmetrically. We detected significant differentiation and copy-number expansion clustered within venom-related gene families, contrasting sharply with a near-complete lack of divergence in chemosensory genes. This decoupled evolution suggests that host finding may rely on behavioural plasticity, whereas physiological compatibility is genetically hard-wired via multi-layered immune-suppression mechanisms. Finally, asymmetrical gene flow in northern populations demonstrates that fine-scale habitat overlap creates ecological connectivity without eroding specialized lineages, as intense host-mediated selection purges maladapted hybrids. Ultimately, our study demonstrates that physiological barriers, rather than behavioural recognition, may maintain specialized parasitoid lineages, providing new insights into the genomic basis of speciation with gene flow in specialized natural enemies.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":"e70589"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13655639/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149163494","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":"Chilling Injury to Algal Symbionts Induces Host Starvation and Metabolic Reorganization in a Temperate Cnidarian.","authors":"Marie Legain, Taissa Lopes Damasceno, Slimane Chaïb, Miriam Reverter, Héloïse Gauthier, Colin Sten Moldenhauer, Paula Isabel Hueso-Jiménez, Suzanne C Mills, Delphine Raviglione, Nils Rädecker, Nathalie Tapissier-Bontemps, Claudia Pogoreutz","doi":"10.1111/mec.70582","DOIUrl":"10.1111/mec.70582","url":null,"abstract":"<p><p>Global temperature anomalies increasingly disrupt the cnidarian-algal symbiosis resulting in a phenomenon termed bleaching. In contrast to heat stress, the mechanisms underlying symbiotic breakdown under cold stress remain largely unknown. Combining physiological and metabolomic measurements, we investigated the response of the photosymbiotic sea anemone holobiont Aiptasia couchii to an experiment mimicking a cold spell in the Mediterranean Sea. Within 4 weeks, we observed the onset of symbiotic breakdown reflected in reduced algal endosymbiont density and chlorophyll a content. While photosynthetic efficiency remained largely unaffected, no gross photosynthesis was detectable in cold-stressed anemones and decreases in glycosyldiacylglycerols and fatty acyl glycosides indicated chloroplast lipid remobilization. This breakdown of symbiotic carbon cycling was reflected in increased dipeptide and ceramide levels suggesting anemones catabolized protein reserves and induced pre-apoptotic pathways. Taken together, these responses suggest a decoupling of light and dark reactions of photosynthesis in cold-stressed endosymbionts, resembling chilling injury in higher plants and free-living microalgae. This chilling-induced collapse of symbiotic nutrient cycling eventually leads to host starvation in cold-stressed Cnidaria. Hence, while cold and heat stress may invoke contrasting physiological effects on endosymbionts, our results suggest that both stressors destabilize the symbiosis through similar mechanisms culminating in host starvation.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":"35 19","pages":"e70582"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13658927/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149163744","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}