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opencc-zeroDec 2014View details →

Data from: Oligocene niche shift, Miocene diversification - cold tolerance and accelerated speciation rates in the St. John's Worts (Hypericum, Hypericaceae)

Background: Our aim is to understand the evolution of species-rich plant groups that shifted from tropical into cold/temperate biomes. It is well known that climate affects evolutionary processes, such as how fast species diversify, species range shifts, and species distributions. Many plant lineages may have gone extinct in the Northern Hemisphere due to Late Eocene climate cooling, while some tropical lineages may have adapted to temperate conditions and radiated; the hyper-diverse and geographically widespread genus Hypericum is one of these. Results:To investigate the effect of macroecological niche shifts on evolutionary success we combine historical biogeography with analyses of diversification dynamics and climatic niche shifts in a phylogenetic framework. Hypericum evolved cold tolerance c. 30 million years ago, and successfully colonized all ice-free continents, where today ~500 species exist. The other members of Hypericaceae stayed in their tropical habitats and evolved into ~120 species. We identified a 15–20 million year lag between the initial change in temperature preference in Hypericum and subsequent diversification rate shifts in the Miocene. Conclusions:Contrary to the dramatic niche shift early in the evolution of Hypericum most extant species occur in temperate climates including high elevations in the tropics. These cold/temperate niches are a distinctive characteristic of Hypericum. We conclude that the initial release from an evolutionary constraint (from tropical to temperate climates) is an important novelty in Hypericum. However, the initial shift in the adaptive landscape into colder climates appears to be a precondition, and may not be directly related to increased diversification rates. Instead, subsequent events of mountain formation and further climate cooling may better explain distribution patterns and species-richness in Hypericum. These findings exemplify important macroevolutionary patterns of plant diversification during large-scale global climate change.

opencc-zeroDec 2018View details →

Data from: Higher incubation temperatures produce long-lasting upward shifts in cold tolerance, but not heat tolerance, of hatchling geckos

Heatwaves are a regular occurrence in Australia, and are predicted to increase in intensity and duration in the future. These changes may elevate temperatures inside lizard nests, shortening the incubation period, so that hatchlings are more likely to emerge during heatwaves. Potentially, developmental plasticity or heat hardening could buffer hatchings from future warming. For example, higher incubation temperatures could shift critical thermal maxima upwards, enabling lizards to withstand higher temperatures. To investigate whether developmental plasticity affects hatchling thermal tolerance, we incubated eggs of the velvet gecko Amalosia lesueurii under two fluctuating incubation treatments to mimic current warm (mean = 24.3°C, range 18.4 - 31.1°C) and future hot (mean = 28.9°C, range 19.1 - 38.1°C) nest temperatures. We maintained the hatchlings under identical conditions, and measured their thermal tolerance (CTmax) at age 14 d and 42 d. We then released hatchlings at field sites, and recaptured individually marked lizards at age six months, to determine whether incubation induced shifts in thermal tolerance were transitory or long-lasting. We found that at age 14 d, hatchlings from the future hot temperature incubation treatment had higher CTmax (mean = 39.96 ± 0.25°C) than hatchlings from the current warm incubation treatment (mean = 39.70 ± 0.36°C). Hatchlings from the warm-incubation treatment also had significantly higher heat hardening capacity (mean = 0.79 ± 0.37°C) than hatchlings from hot-temperature incubation treatment (mean = 0.47 ± 0.17°C). However, both of these incubation-induced effects did not persist into later life. By contrast, incubation treatment had significant and long-lasting effects on the cold tolerance of hatchlings. At age 14 d, warm-incubated hatchlings tolerated colder temperatures (CTmin = 11.24 ± 0.41°C) than hot-incubated hatchlings (CTmin = 14.11 ± 0.25°C). This significant difference in cold tolerance persisted into the juvenile life stage, and was present in 6 month old lizards that we recaptured from field sites. This finding indicates that upward shifts in cold tolerance caused by higher nest temperatures might impact negatively on overwinter survival of lizards, but field studies linking fitness to thermal tolerance are necessary to test this idea. Overall, our results suggest that developmental plasticity for heat tolerance is unlikely to buffer lizard populations from increasing temperatures.

opencc-zeroDec 2018View details →

Data from: Quantitative trait loci for cold tolerance in chickpea

Fall-sown chickpea (Cicer arietinum L.) yields are often double those of spring-sown chickpea in regions with Mediterranean climates that have mild winters. However, winter kill can limit the productivity of fall-sown chickpea. Developing cold-tolerant chickpea would allow the expansion of the current geographic range where chickpea is grown and also improve productivity. The objective of this study was to identify the quantitative trait loci (QTL) associated with cold tolerance in chickpea. An interspecific recombinant inbred line population of 129 lines derived from a cross between ICC 4958, a cold-sensitive desi type (C. arietinum), and PI 489777, a cold-tolerant wild relative (C. reticulatum Ladiz), was used in this study. The population was phenotyped for cold tolerance in the field over four field seasons (September 2011–March 2015) and under controlled conditions two times. The population was genotyped using genotyping-by-sequencing, and an interspecific genetic linkage map consisting of 747 single nucleotide polymorphism (SNP) markers, spanning a distance of 393.7 cM, was developed. Three significant QTL were found on linkage groups (LGs) 1B, 3, and 8. The QTL on LGs 3 and 8 were consistently detected in six environments with logarithm of odds score ranges of 5.16 to 15.11 and 5.68 to 23.96, respectively. The QTL CT Ca-3.1 explained 7.15 to 34.6% of the phenotypic variance in all environments, whereas QTL CT Ca-8.1 explained 11.5 to 48.4%. The QTL-associated SNP markers may become useful for breeding with further fine mapping for increasing cold tolerance in domestic chickpea.

opencc-zeroDec 2020View details →

Multiple paths to cold tolerance: the role of environmental cues, morphological traits and the circadian clock gene vrille

Background: Tracing the association between insect cold tolerance and latitudinally and locally varying environmental conditions, as well as key morphological traits and molecular mechanisms, is essential for understanding the processes involved in adaptation. We explored these issues in two closely-related species, Drosophila montana and Drosophila flavomontana, originating from diverse climatic locations across several latitudes on the coastal and mountainous regions of North America. We also investigated the association between sequence variation in one of the key circadian clock genes, vrille, and cold tolerance in both species. Finally, we studied the impact of vrille on fly cold tolerance and cold acclimation ability by silencing it with RNA interference in D. montana. Results: We performed a principal component analysis (PCA) on variables representing bioclimatic conditions on the study sites and used latitude as a proxy of photoperiod. PC1 separated the mountainous continental sites from the coastal ones based on temperature variability and precipitation, while PC2 arranged the sites based on summer and annual mean temperatures. Cold tolerance tests showed D. montana to be more cold-tolerant than D. flavomontana and chill coma resistance (CTmin) of this species showed an association with PC2. Chill coma recovery time (CCRT) of both species improved towards northern latitudes, and in D. flavomontana this trait was also associated with PC1. D. flavomontana flies were darkest in the coast and in the northern mountainous populations, but coloration showed no linkage with cold tolerance. Body size decreased towards cold environments in both species, but only within D. montana populations largest flies showed fastest recovery from cold. Finally, both the sequence analysis and RNAi study on vrille suggested this gene to play an essential role in D. montana cold resistance and acclimation, but not in recovery time. Conclusions: Our study demonstrates the complexity of insect cold tolerance and emphasizes the need to trace its association with multiple environmental variables and morphological traits to identify potential agents of natural selection. It also shows that a circadian clock gene vrille is essential both for short- and long-term cold acclimation, potentially elucidating the connection between circadian clock system and cold tolerance.

opencc-zeroDec 2021View details →

Cold tolerance of laboratory-reared Asian longhorned beetles

Low winter temperatures in temperate climates can limit the success of non-native species. The Asian longhorned beetle, Anoplophora glabripennis, is an invasive wood-boring pest of hardwood trees in North America and Europe. Native A. glabripennis populations are spread across several climate zones in China and the Korean Peninsula and are likely to encounter low temperatures in at least some of this range. Understanding the lethal limits of the overwintering life stages of A. glabripennis is essential for accurately modeling the risk that invasive populations pose to non-native environments. In this study, we provide the first systematic characterization of the cold tolerance strategy and lower lethal limits of A. glabripennis eggs, larvae, and pupae. In diapausing larvae, the most common overwintering stage in this species, we measure hemolymph glycerol and osmolality and identify the effects of prolonged low temperature exposure. In developing pupae, we identify sublethal effects caused by low temperature exposure before freezing. Eggs and larvae were the most cold-tolerant life stages; eggs were freeze-avoidant with an average supercooling point of -25.8 °C and larvae were freeze tolerant with an LT90 of -25 °C. Hemolymph osmolality of freeze-tolerant larvae, on average, increased to 811 mOsm during chilling. This increase was primarily driven by a concurrent, average increase of 232 mM hemolymph glycerol. Pupae died upon exposure to freezing temperatures, but accumulate strong sublethal effects prior to freezing, indicating that they are chill susceptible. Taken together, these data will be useful to inform species distribution modeling in A. glabripennis.

opencc-zeroAug 2022View details →

Data from: Plasticity drives extreme cold tolerance of emerald ash borer (Agrilus planipennis) during a polar vortex

Invasive species must often survive combinations of environmental conditions that differ considerably from their native range; however, for a given species it is unclear whether improved tolerance is the result of phenotypic plasticity or genetic adaptation (or both). Agrilus planipennis (Coleoptera: Buprestidae; the emerald ash borer) is an invasive pest of Fraxinus trees in North America and Europe. Previous studies in southwestern Ontario, Canada, showed that A. planipennis is freeze avoidant, preventing internal ice formation by accumulating molar concentrations of glycerol in its hemolymph and depressing its supercooling point (SCP, the temperature at which it freezes). The cold tolerance of these southwestern Ontario animals was used to predict potential distribution, revealing that some Canadian cities should be too cold to allow populations to persist. However, a small population of A. planipennis has persisted in Winnipeg, Manitoba, Canada, through several severe 'polar vortex' events. In 2018/19, we collected A. planipennis larvae and prepupae from Winnipeg, Manitoba and Southern Ontario, and found that individuals from Winnipeg were extremely cold tolerant – with SCPs as low as -52 °C in prepupae (compared to 32 °C in Southern Ontario), and survival of unfrozen individuals exposed to -50 °C for one hour. This cold tolerance was accompanied by higher hemolymph osmolality and glycerol concentration than in the SW Ontario individuals. To distinguish between phenotypic plasticity and local adaptation, in 2020/21 we overwintered Winnipeg-sourced individuals either outdoors in southwestern Ontario or in a simulated Winnipeg winter. Simulated Winnipeg winter individuals had cold tolerance similar to those overwintered in Winnipeg, while southwestern Ontario overwintered individuals had cold tolerance similar to those collected previously in the region. The simulated winter individuals had higher hemolymph glycerol concentrations than southwestern Ontario overwintered animals, at least in part due to greater dehydration. Thus, A. planipennis are cold-tolerant enough to survive some of the harshest winters where their host trees can grow, and most likely attain this cold tolerance via phenotypic plasticity. These findings raise the importance of delineating sensitivity of conclusions to unexpected phenotypic plasticity when predicting potential distributions of new invasives or responses to climate change. The data in this dataset are the SCPs and treatment data for the experimental animals used in these cold tolerance experiments.

FIG. 3 in Sex-Dependent Cold Tolerance at the Northern Invasive Range Limit of Gambusia affinis on Cape Cod, Massachusetts

FIG. 3. Lower (left) and upper (right) reported thermal tolerances for Gambusia affinis and Gambusia holbrooki. Each point and line represent the mean and range, respectively, for a particular population, with lethal and non-lethal assays distinguished. Significant variation in reported values for a given population is typically due to varied acclimation temperatures and separate testing on males and females. Gray lines show extrapolated 50% lower thermal tolerance predictions and standard errors for average males and females from our study. Letters indicate sexes included, and numbers refer to studies in Table S1 (see Data Accessibility).

FIG. 2 in Sex-Dependent Cold Tolerance at the Northern Invasive Range Limit of Gambusia affinis on Cape Cod, Massachusetts

FIG. 2. Estimated lower temperature of 50% loss of response to stimulus (LRT50) and 50% mortality (LT50) for male and female Gambusia affinis of various sizes from the Quashnet River, Massachusetts, USA. Thinner, lighter lines represent 6 one standard error. Note that estimates below 1.58C are extrapolations beyond the range of our data.

FIG. 1 in Sex-Dependent Cold Tolerance at the Northern Invasive Range Limit of Gambusia affinis on Cape Cod, Massachusetts

FIG. 1. Proportion of mosquitofish that responded to a stimulus and maintained orientation while experiencing progressively decreasing temperature. Points show average proportions for all females and males. Lines show model predictions: dark lines for fish of average mass; thin, light lines for fish at the 5% lower range of fish mass; and thick, light lines for fish at the 95% range of fish mass (calculated separately for each sex). Dashed lines show model extrapolation between 1.5 and 08C.

FIG. 4 in Sex-Dependent Cold Tolerance at the Northern Invasive Range Limit of Gambusia affinis on Cape Cod, Massachusetts

FIG. 4. Daily temperature ranges for Quashnet River surface water from three thermistors over four years. Data from Briggs et al. (2018). Lines and bars show mean 6 standard error 50% lower thermal response (LRT50) and lower thermal tolerance (LT50) predictions for average males and females from our study.

opencc-zeroJul 2021View details →

Arboreality drives heat tolerance while elevation drives cold tolerance in tropical rainforest ants

Determining how species thermal limits correlate with climate is important for understanding biogeographic patterns and assessing vulnerability to climate change. Such analyses need to consider thermal gradients at multiple spatial scales. Here we relate thermal traits of rainforest ants to microclimate conditions from ground to canopy (microgeographic scale) along an elevation gradient (mesogeographic scale) and calculate warming tolerance in the Australian Wet Tropics Bioregion. We test the thermal adaptation and thermal niche asymmetry hypotheses to explain interspecific patterns of thermal tolerance at these two spatial scales. We tested CTmin, CTmax, and calculated CTrange using ramping assays for 74 colonies of 40 ant species collected from terrestrial and arboreal habitats at lowland and upland elevation sites and recorded microclimatic conditions for one year. Within sites, arboreal ants were exposed to hotter microclimates and on average had a 4.2°C (95% CI: 2.7 – 5.6°C) higher CTmax, and 5.3°C (95% CI: 3.5 – 7°C) broader CTrange than ground-dwelling ants. This pattern was consistent across the elevation gradient, whether it be the hotter lowlands or the cooler uplands. Across elevation, upland ants had significantly lower CTmin than lowland ants, whereas the change in CTmax was less pronounced, and CTrange did not change over elevation. Differential exposure to microclimates, due to localised niche preferences, drives divergence in CTmax while environmental temperatures along the elevation gradient drive divergence in CTmin. Our results suggest that both processes of thermal adaptation and thermal niche asymmetry are at play depending on the spatial scale of observation, and we discuss potential mechanisms underlying these patterns. Despite the broad thermal tolerance range of arboreal rainforest ants, lowland arboreal ants had the lowest warming tolerance and may be most vulnerable to climate change.

opencc-zeroNov 2022View details →

Genomic shifts, phenotypic clines and fitness costs associated with cold-tolerance in the Asian tiger mosquito

Climatic variation is a key driver of genetic differentiation and phenotypic traits evolution, and local adaptation to temperature is expected in widespread species. We investigated phenotypic and genomic changes in the native range of the Asian tiger mosquito, Aedes albopictus. We first refine the phylogeographic structure based on genome-wide regions (1,901 double-digest restriction-site associated DNA single nucleotide polymophisms [ddRAD SNPs]) from 41 populations. We then explore the patterns of cold adaptation using phenotypic traits measured in common garden (wing size and cold tolerance) and genotype–temperature associations at targeted candidate regions (51,706 exon-capture SNPs) from nine populations. We confirm the existence of three evolutionary lineages including clades A (Malaysia, Thailand, Cambodia, and Laos), B (China and Okinawa), and C (South Korea and Japan). We identified temperature-associated differentiation in 15 out of 221 candidate regions but none in ddRAD regions, supporting the role of directional selection in detected genes. These include genes involved in lipid metabolism and a circadian clock gene. Most outlier SNPs are differently fixed between clades A and C, whereas clade B has an intermediate pattern. Females are larger at higher latitudes yet produce no more eggs, which might favor the storage of energetic reserves in colder climates. Nondiapausing eggs from temperate populations survive better to cold exposure than those from tropical populations, suggesting they are protected from freezing damages but this cold tolerance has a fitness cost in terms of egg viability. Altogether, our results provide strong evidence for the thermal adaptation of A. albopictus across its wide temperature range.

opencc-by-2.0Jun 2023View details →

Fitness and cold tolerance of Spodoptera frugiperda fed on corn and two winter crops(Original data)

Fall armyworm (FAW) Spodoptera frugiperda is a major migratory and polyphagous pest. Overwintering, migrating and colonizing characters of FAW are closely related to vegetation and host adaptation. In this study, oviposition preference, feeding preference, fitness and cold tolerance of FAW fed on spring & summer crop (corn) and two winter crops (cabbage, Brassica campestris and rape, B. napus). We observed that FAW could complete their life cycle by feeding cabbage and rape, although fitness was not as good as corn. FAW fed on cabbage had higher survival, pupal weight, and host suitability index than rape while larvae preferred to feed on rape leaves and females preferred to lay eggs on rape plants. In addition, FAW larvae fed on cabbage had the shortest recovery time from chill coma compared to corn and rape, indicating that cold tolerance of FAW larvae was improved by feeding on cabbage. Consequently, cabbage could be an ideal host for FAW which needed to survive and reproduction in winter. These results improve our understanding of host selection and adaption of FAW, as well as lay a foundation for the prediction of FAW overwintering.

ClinicalTrials.gov32/100

Efficacy & Tolerability of a Specific Plantain,Thyme and Honey Cough Syrup vs Placebo in Child Cough Due to Common Cold

ClinicalTrials.gov study NCT02486835. IPD Sharing: Not stated. Countries: 1. Publications: 9.

restrictedIPD-UNDECIDEDFeb 2026View details →

ClinicalTrials.gov32/100

Study of Safety, Tolerability and Efficacy of DFV890 in Participants With Familial Cold Auto-inflammatory Syndrome (FCAS)

ClinicalTrials.gov study NCT04868968. IPD Sharing: YES. Countries: 3. Publications: 0.

controlledIPD-YESFeb 2026View details →