Biology subjects

Chuang, A.

Publications and source records attributed to Chuang, A..

5 recordsLinked to original sources

bioRxiv2026

Urbanization effects are trait-specific and city-dependent across a widespread spider's global range

Urban environments impose strong selective pressures through biotic and abiotic factors, driving changes in behavior, physiology, and morphology. Yet, responses vary across taxa and cities, and it remains unclear which traits respond consistently and what factors moderate this variation. We addressed these questions using the widespread European garden spider (Araneus diadematus) as a model, measuring size, color, and web-building traits along urban-rural transects in 22 cities across its distribution range. Using a meta-analytic framework, we assessed how city-specific characteristics influenced trait variation. Urbanization consistently reduced relative abdomen surface area, a proxy for body condition. Exploratory meta-regressions suggest that web-building response was predicted by temperature: compared to their non-urban surroundings, urban webs are larger in colder regions and smaller in warmer regions. In contrast, body size and abdomen brightness varied among cities without clear environmental predictors. These findings show that urbanization effects are trait- and context-dependent, likely influenced by local factors such as heat island intensity, microclimate, or prey availability. Linking within- and between-city variation will improve understanding of species phenotypic responses to urban environments.

ecology↗

bioRxiv2025

Early Changes in Respiration and Motor Activity after Spinal Cord Injury Predict Pain-Related Outcomes in Mice

Spinal cord injuries (SCIs) may lead to the emergence of chronic pain many weeks after injury. Using the thoracic contusion model of SCI-induced neuropathic pain, we investigated whether early changes in mouse respiration or motor activity could predict and differentiate emergent dysfunction with focus on pain. We measured respiratory rate (RR) and movement (motor activity) in freely behaving mice before and at several time points following SCI. We then assessed behavioral signs of pain or thermal dysregulation by testing evoked hindpaw withdrawal responses to mechanical and thermal heating stimuli and temperature preferences at four weeks after injury. For 2-3 days after injury, mice exhibited sharp decreases in movement and RR variability, but these two parameters were uncorrelated within animals. Mice showed signs of mechanical and thermal hypersensitivity and preferences for warmer temperatures four weeks after injury. Interestingly, mice that moved the least 1 day after SCI preferentially underwent hindpaw mechano-sensitivity (r = 0.67, p =.036), whereas mice with large decreases in RR variability that recovered by 8 days post-injury preferred higher temperatures in the thermal preference test (r = 0.79, p =.007). Thus, early changes in movement and RR variability may differentially predict future hypersensitivity and thermal dysfunction. More broadly, early post-injury physio-behavioral events could inform novel interventions to mitigate subsequent emergent dysfunction after SCI.

physiology↗

bioRxiv2025

Evolution of dominance in a Mendelian trait is linked to the evolution of environmental plasticity.

Allelic dominance and phenotypic plasticity both influence how genetic variation is expressed in phenotypes, shaping evolutionary responses to selection. In both cases, changes in genotype or environment can cause sharp, nonlinear phenotypic shifts, hinting at shared underlying features of development that may link dominance and plasticity. Here, we investigate these links using a Mendelian, female-limited color dimorphism found in many species of the Drosophila montium lineage. In most species, the Dark allele is dominant, but two species--D. jambulina and D. cf. bocqueti--have been reported to have dominant Light alleles. We show that in both Dark-dominant and Light-dominant species, the color dimorphism is linked to the same locus: the POU domain motif 3 (pdm3) transcription factor. We then demonstrate that the interspecific differences in dominance relationships between pdm3 alleles are due to changes in phenotypic plasticity. In the Dark-dominant species D. rufa and D. burlai, the Dark allele is dominant across all developmental temperatures. In contrast, in both Light-dominant species, dominance is temperature-dependent, with the Light allele becoming increasingly dominant at higher temperatures. These results suggest a mechanistic connection between the evolution of dominance and phenotypic plasticity. We propose this connection may emerge from threshold-like properties of developmental systems. Teaser textThis study reveals a direct relationship between the evolution of dominance and phenotypic plasticity in a Mendelian, female-limited color dimorphism. This trait is linked to the same transcription factor gene, pdm3, in multiple species of the Drosophila montium lineage. However in some species, the Light pdm3 allele becomes increasingly dominant at higher temperature, while in others the Dark allele is fully dominant under all conditions. Based on these results, we propose that the evolution of dominance and plasticity may be connected by threshold-like properties of developmental systems.

evolutionary biology↗

bioRxiv2023

Meta-analysis of herbicide non-target effects on pest natural enemies

A critical component of integrated pest management is minimizing disruption of biological control by reducing use of pesticides with significant non-target effects on natural enemies. Insecticide non-target effects testing for natural enemies has become increasingly common, but research examining the non-target effects of herbicides on natural enemies is scarce and recommendations regarding herbicide selectivity are non-existent. We used meta-analysis to summarize laboratory bioassays testing non-target effects of herbicides on arthropod natural enemies and identify patterns in taxon susceptibility and active ingredient toxicity. Data was extracted from 103 papers representing 801 total observations. Herbicides increased natural enemy mortality and decreased longevity, reproduction, and predation. Mesostigmatan mites and hemipterans were the most sensitive to herbicides and spiders, neuropterans, and hymenopterans were the least sensitive. Mortality was higher in juvenile predators versus parasitoids, but did not differ between adults; parasitoid juveniles are likely better protected within the host. In terms of acute mortality, metribuzin, glufosinate, and oxyfluorfen were the most harmful herbicides. Only nicosulfuron, rimsulfuron, pendimethalin, phenmedipham, atrazine, and urea did not increase natural enemy mortality. The large effect size of glufosinate is particularly concerning, as it is the most likely replacement herbicide for glyphosate in many crops. Many active ingredients remain under-studied. Our analysis indicates that herbicides have a strong potential to disrupt biological control in cropping systems. Simple SummaryReducing the use of pesticides that harm natural enemies of crop pests is important to pest management. Currently, there is limited information on how herbicides might affect natural enemies. The researchers found that herbicides increased natural enemy mortality and reduced their longevity and efficacy as predators. Some potential glyphosate replacement herbicides were more harmful than glyphosate. There was little or no data available for many herbicides and beneficial insects, indicating that much more research is needed on this topic.

ecology↗

bioRxiv2023

Veni, vidi, vici? Future spread and ecological impacts of a rapidly-expanding invasive predator population

Economic and ecological consequences of invasive species make biological invasions an influential driver of global change. Monitoring the spread and impacts of non-native species is essential, but often difficult, especially during the initial stages of invasion. The Joro spider, Trichonephila clavata (L. Koch, 1878, Araneae: Araneidae), is a large-bodied orb weaver native to Asia, likely introduced to northern Georgia, U.S. around 2010. We investigated the nascent invasion of T. clavata by constructing species distribution models (SDMs) from crowdsourced data to compare the climate T. clavata experiences in its native range to its introduced range. We found evidence that the climate of T. clavatas native range differs significantly from its introduced range and that the most similar climate in North America to its native range is to the north of its current introduced range. We then compared the SDM predictions to current observations of spread. Consistent with predictions, T. clavata appears to be spreading faster to the north than to the south. Lastly, we conducted surveys to investigate potential ecological impacts of T. clavata on the diversity of native orb weaving spiders. Importantly, Trichonephila clavata was the most common and abundant species observed in the survey, and was numerically dominant at half of the sites it was present in. Our models also suggest that there is lower native orb weaver species richness and diversity closer to where T. clavata was initially found and where it has been established the longest, though human population density complicates this finding. This early study is the first to forecast how widely this spider may spread in its introduced range and explore potential ecological impacts of T. clavata, and we call for continued investigation of this invasions effects.

ecology↗