2025 Hyper Recent •CC0 1.0 Universal

This work is dedicated to the public domain. No rights reserved.

Access Preprint From Server
July 4th, 2025
Version: 1
iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau, Landau, Germany
evolutionary biology
biorxiv

Pollution-Driven Selection in Riparian Ecosystems: Genome-Wide Responses to Bacillus thuringiensis israelensis and Copper in a Non-biting Midge

Roeder, N.Open in Google Scholar•Kolbenschlag, S.Open in Google Scholar•Pietz, S.Open in Google Scholar•Brennan, R. S.Open in Google Scholar•Bundschuh, M.Open in Google Scholar•Pfenninger, M.Open in Google Scholar•Schwenk, K.Open in Google Scholar

Riparian ecosystems are vital interfaces between aquatic and terrestrial environments but are increasingly impacted by anthropogenic pollution. In these systems, merolimnic insects serve as crucial ecological links, occupying aquatic habitats as larvae and terrestrial environments as adults, thus being an essential food source in both. Consequently, pollutant exposure during the aquatic larval stage can have cascading effects across ecosystem boundaries. While the ecological consequences of such exposure are well documented, the evolutionary potential of merolimnic insects to adapt to chronic pollution remains poorly understood. To address this, we previously conducted a selection experiment exposing populations of the non-biting midge Chironomus riparius to the mosquito larvicide Bacillus thuringiensis israelensis (Bti) or heavy metal copper over approximately eight generations, which revealed only limited evidence of consistent phenotypic adaptation. Here we use whole-genome sequencing of these populations to assess their genomic responses to chronic pollutant exposure. Despite similar phenotypic sensitivity in pre-exposed and naive populations, we detected distinct stressor-specific genomic responses. Copper exposure induced a significant genome-wide reduction in nucleotide diversity and evidence of selection-driven allele frequency changes, while Bti effects were dominated by heterogeneous, replicate-specific shifts, potentially reflecting drift or selection on multiple redundant pathways. Functional enrichment analyses indicated early-stage adaptation: immune- and apoptosis-related pathways were enriched under Bti, while metal detoxification and DNA repair pathways were enriched under copper, highlighting distinct adaptive mechanisms despite weak genome-wide signals of selection. Our findings demonstrate that Evolve and Resequencing approaches enable the detection of early genomic signals of adaptation even when phenotypic change is subtle or absent, offering a powerful framework for studying evolutionary responses to environmental pollution.

Similar Papers

biorxiv
Sat Jul 05 2025
The complex interaction between megaherbivores, climate and fire has shaped the evolution and distribution of plant spinescence across biogeographical realms
The evolutionary arms race between plants and herbivores has led to numerous plant adaptations, including spinescence. However, whether spinescence evolved primarily in response to herbivory, or whether abiotic conditions also played a role, remains unknown. We integrated phylogenetic, geographic, and trait data for 2,686 species of an ecologically diverse and spiny pantropical lineage, mimosoid l...
Souza Ferreira, R.
•
Ringelberg, J.
•
Hughes, C.
•
Arle, E.
...•
Onstein, R.
biorxiv
Sat Jul 05 2025
Improving Joint Estimation of Vital Rates in IPMs via Gaussian Processes and ABC
Developing population dynamic models that can flexibly adapt to different species remains a challenge due to the context-dependent nature of demographic studies. This work introduces ABC_GP IPM, a novel Integral Projection Model (IPM) framework, aimed at mitigating key limitations associated with traditional IPMs, including (i) reliance on predefined vital rate models with restrictive assumptions,...
Zhu, Z.
•
Christodoulou, M. D.
•
Steinsaltz, D.
biorxiv
Sat Jul 05 2025
Socioeconomic predictors of knockdown resistance in Aedes albopictus (Diptera: Culicidae)
Knockdown resistance (kdr) in the mosquito Aedes albopictus (Skuse) jeopardizes the effectiveness of insecticidal control. This is a pressing issue given the expanding range of the species and its role as vector to harmful viruses. Effectively preventing the emergence of resistance or removing the conditions that positively select for kdr mutations requires us first to understand how these conditi...
Butler, C. D.
•
Ding, J. Y.
•
Baltzegar, J. F.
•
Brown, Z. S.
...•
Reiskind, M. H.
biorxiv
Sat Jul 05 2025
Quantitative genetics of shy-bold behaviour and plastic response to novel predator cues in the cherry shrimp, Neocaridina davidi
Understanding the genetic basis of behavioural variation among-individuals is vital for predicting if, when, and how quickly behaviour can evolve under selection. However, in heterogeneous environments, behavioural plasticity (a source of within-individual variation) may also contribute to the phenotypic variance that can be selected on. If so, a complete picture of evolutionary potential, require...
Wilson, A.
•
Rickward, R.
•
Santostefano, F.
biorxiv
Sat Jul 05 2025
Integrated landscape genomics reveals biogeography and climate-driven local adaptation in high-altitudes
High-elevation environments harbor unique species adapted to altitudinal and environmental extremes. However, due to logistical challenges of sampling such species throughout their distribution across steep and varied terrains, studies often lack comprehensive evidence to understand patterns of population divergence, local adaptation, and how current adaptations may influence future vulnerability....
Wang, N.
•
Ghimire, P.
•
Chhetri, P.
•
Ghimire, N.
...•
Lamichhaney, S.
biorxiv
Sat Jul 05 2025
Spread of a single superclone drives insecticide resistance in Acyrthosiphon kondoi across an invasive range
Populations under similar selection pressures may adapt via parallel evolution or dispersal of advantageous alleles. Here, we investigated insecticide resistance in the invasive blue-green aphid, Acyrthosiphon kondoi, which reproduces clonally in Australia and has rapidly developed resistance across geographic locations. Using genomic, transcriptomic, and experimental approaches, we explored the e...
Thia, J. A.
•
Hunt, B. J.
•
Wang, S.
•
Troczka, B. J.
...•
Hoffmann, A. A.
biorxiv
Fri Jul 04 2025
Gamete release in Ciona robusta: roles of gonadotropin-releasing hormone and the photoreception system
Gamete release, an essential event for animals, is regulated by various factors including environmental stimuli, neural circuit, and endocrine molecules. In this study, we investigated the mechanisms regulating gamete release in the ascidian Ciona robusta, part of the sister group of vertebrates. Ciona is a hermaphrodite, releasing sperm first from orange-pigmented organ (OPO) at the end of the sp...
Osugi, T.
•
Matsubara, S.
•
Shiraishi, A.
•
Wada, A.
...•
Satake, H.
biorxiv
Fri Jul 04 2025
Songs distinguish the cryptic giant hummingbird species and clarify range limits
Vocal traits are often essential for distinguishing phenotypically cryptic taxa. The hummingbird genus Patagona comprises two species, near identical in plumage and morphology, that differ in almost every aspect of their ecology and evolution: The Northern Giant Hummingbird (Patagona peruviana) and Southern Giant Hummingbird (Patagona gigas). Here, we characterized the songs of both giant hummingb...
Robinson, B. W.
•
Zucker, R. J.
•
Witt, C. C.
•
Valqui, T.
•
Williamson, J. L.
biorxiv
Fri Jul 04 2025
Rapid spread of knockdown resistance allele frequencies in a suburban population of Aedes albopictus
Aedes albopictus is a major vector of arboviral diseases and is often targeted by pyrethroid-based mosquito control in residential areas. While knockdown resistance (kdr) mutations are well documented in Ae. aegypti, their emergence in Ae. albopictus has been less studied, particularly in suburban environments where insecticide application is often uncoordinated. Understanding the temporal and spa...
Baltzegar, J. F.
•
Butler, C.
•
Beeson, C.
•
Reed, E. M.
...•
Reiskind, M. O. B.
biorxiv
Fri Jul 04 2025
Functional characterization of specialized immune cells in a cnidarian reveals an ancestral antiviral program
Examining early-branching animal phyla can help reconstructing the evolutionary origins of immune cells. Here, we characterized immune-related cell programs in embryos of the sea anemone Nematostella vectensis, a model of Cnidaria, which diverged ~600 million years ago from other animals. Using a transgenic Nematostella reporter line expressing mCherry under the RLRb antiviral promoter, we identif...
Kozlovski, I.
•
Sharoni, T.
•
Levy, S.
•
Jaimes-Becerra, A.
...•
Moran, Y.