Warming temperatures caused by climate change are predicted to vary temporally and spatially. For mid‐ and high‐latitude reptiles, the seasonal variation in warming temperatures experienced by ...embryos and hatchlings may determine offspring fitness, yet this has remained largely unexplored.
To evaluate the independent and interactive influence of seasonal variation in warming temperatures on embryonic and hatchling development, we incubated eggs and reared hatchlings of a cold‐climate oviparous ectothermic species, the Heilongjiang grass lizard (Takydromus amurensis), following a 2 × 2 factorial design (present climate versus warming climate for embryos × present climate versus warming climate for hatchlings). We then evaluated embryonic and hatchling development, including hatching success, incubation period, initial hatchling body size, hatchling metabolic rate, growth rate and survival in the mesocosms.
We found that warming temperatures shortened the incubation period and produced hatchlings with higher survival rates than those incubated under the present climate conditions. Similarly, hatchlings reared under a warming climate had similar growth rates and resting metabolic rates, but higher survival rates than those reared under the present climate. Hatchlings that experienced both warming incubation and warming growth conditions had the highest survival rates.
This study revealed that moderate warming temperatures (Representative Concentration Pathway, RCP 4.5, 1.1–2.6°C) experienced by embryos and hatchlings interact to benefit hatchling fitness in cold‐climate oviparous ectotherms. Our study also highlighted the importance of integrating seasonal variation in warming temperatures when evaluating the responses to climate warming in multiple developmental stages in oviparous ectotherms.
摘要
气候变暖导致的温度升高存在着时空变异。对于中高纬度的爬行动物而言, 胚胎发育和后代生长经历的变暖温度可能存在季节间差异。而此种季节间差异的变暖温度如何影响后代的适合度, 目前仍然知之甚少。
为了评估季节间差异的变暖温度对胚胎发育和后代发育的独立或交互的影响, 我们以一种寒冷气候区分布的卵生外温物种黑龙江草蜥 (Takydromus amurensis) 为研究对象, 利用2 × 2因子控制的实验方案开展胚胎孵化和幼体饲养等工作 (当前气候与变暖气候胚胎孵化 × 当前气候与变暖气候幼体饲养)。并且, 我们检测了胚胎和幼体发育的指标, 包括孵化成功率、孵化期和幼体初始体长和体重、幼体代谢率、生长率和存活率等。
我们发现, 模拟气候变暖的孵化环境缩短了胚胎的孵化期, 并且孵出的幼体具有更高的存活率。此外, 尽管与当前气候下饲养的幼体在生长率和代谢率上并无差异, 但是在模拟变暖气候下饲养的幼体的存活率得到了显著地提升。从胚胎发育到后代生长阶段均经历变暖温度的幼体, 具有最高的存活率。
本研究揭示了胚胎和幼体均经历中等程度的气候变暖 (RCP 4.5, 1.1–2.6°C) 交互地提升了幼体的适合度, 证明了中等程度的气候变暖可能有益于寒冷气候的卵生外温动物。不仅如此, 本研究也强调了在评估具有多生活史阶段的卵生外温动物对气候变暖的响应时, 考虑季节间温度变暖差异的重要性。
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As postulated by life‐history theory, not all life‐history traits can be maximized simultaneously. In ectothermic animals, climate warming is predicted to increase growth rates, but at a cost to ...overall life span. Maternal effects are expected to mediate this life‐history trade‐off, but such effects have not yet been explicitly elucidated.
To understand maternal effects on the life‐history responses to climate warming in lizard offspring, we conducted a manipulative field experiment on a desert‐dwelling viviparous lacertid lizard Eremias multiocellata, using open‐top chambers in a factorial design (maternal warm climate and maternal present climate treatments × offspring warm climate and offspring present climate treatments).
We found that the maternal warm climate treatment had little impact on the physiological and life‐history traits of adult females (i.e. metabolic rate, reproductive output, growth and survival). However, the offspring warm climate treatment significantly affected offspring growth, and both maternal and offspring warm climate treatments interacted to affect offspring survival.
Offspring from the warm climate treatment grew faster than those from the present climate treatment. However, the offspring warm climate treatment significantly decreased the survival rate of offspring from maternal present climate treatment, but not for those from the maternal warm climate treatment.
Our study demonstrates that maternal effects mediate the trade‐off between growth and survival of offspring lizards, allowing them to grow fast without a concurrent cost of low survival rate (short life span). These findings stress the importance of adaptive maternal effects in buffering the impact of climate warming on organisms, which may help us to accurately predict the vulnerability of populations and species to future warming climates.
The authors fully factorial warming experiment using open‐top chambers demonstrated that maternal effects mediate the growth‐survival tradeoff of lizards under climate warming. This finding challenges a rarely tested assumption underlying life‐history tradeoff: the limitation of an energy budget, and stresses the importance of adaptive maternal effects in buffering the impact of climate warming on organisms.
Identifying intrinsic and extrinsic sources of variation in life history traits among populations has been well-studied at the post-embryonic stage but rarely at the embryonic stage. To reveal these ...sources of variation in the developmental success of embryos, we measured the physical characteristics of nest environments and conducted reciprocal egg-swap experiments in two populations of the toad-headed agamid lizard (
Phrynocephalus przewalskii
), isolated from each other by a mountain range. We determined the effects of population origin and nest environment on embryonic and offspring traits related to developmental success, including incubation period, hatching success, and offspring growth and survival. Females from the northern population constructed deeper nests that were colder and wetter than those from the southern population. Northern embryos had higher hatching success than the southern embryos when incubated at the northern nest environment, but not when they were incubated at the southern nest environment. The southern hatchlings grew faster than the northern hatchlings when incubated at the southern nest environment, but not after incubation at the northern nest environment. These phenomena likely reflect local adaptation of embryonic development to their nest environments among populations in lizards. In addition, the southern hatchlings had higher survivorship than the northern hatchlings regardless of nest environment, suggesting the southern population has evolved a superior phenotype at the hatchling stage to maximize its fitness.
Herein, a new hybrid, 1,3-bis(1-methylimidazolium)propanePb2I6 (1), was synthesized and thoroughly characterized using microanalysis, thermogravimetric analysis (TG), differential scanning ...calorimetry (DSC), and powdered X-ray diffraction (PXRD) techniques. The crystal structure of 1 reveals one-dimensional face-sharing PbI6 octahedral chains composed of Pb2+ and I− ions, with the disordered 1,3-bis(1-methylimidazolium)propane dications positioned between these inorganic chains. Remarkably, 1 exhibits high dielectric permittivity (∼200) across a wide temperature range of 123–423 K. Moreover, it demonstrates a relaxation-induced dielectric pulsing effect-like, characterized by a broad and temperature-independent dielectric anomaly peak around 263 K in ε'−T plots. The mechanisms responsible for the high dielectric permittivity and the origin of the relaxation-induced dielectric pulsing effect-like are further discussed through a comprehensive analysis of the variable-temperature crystal structure.
A hybrid crystal containing one-dimensional face-sharing PbI6 octahedral chains exhibits high dielectric permittivity across a wide temperature range of 123–423 K and a dielectric pulsing effect-like. Display omitted
•Iodoplumbate hybrid contains face-sharing PbI6 octahedral chains.•Iodoplumbate hybrid features high dielectric permittivity.•Iodoplumbate hybrid exhibits relaxation-induced dielectric pulsing effect-like.
Higher temperatures enhance ectothermic metabolism and development, which can reduce individual health and life expectancy, and therefore increase their vulnerability to climate warming. However, the ...mechanistic causes and consequences of such a temperature-driven impact remain unclear. Our study aimed to address two questions: (1) does climate warming alter early-life growth and physiology, and, if so, what are the associated carry-over effects in terms of reduced survival, increased oxidative stress and telomere shortening? (2) can oxidative stress and telomere dynamics at early life stages predict the effect of climate warming on individual survival? To answer these questions, we conducted a longitudinal experiment under semi-natural conditions where we exposed multiocellated racerunner (Eremias multiocellata) to warming conditions from juvenile to adult stages. We found that exposure to climate warming enhanced growth rates, induced oxidative stress, and shortened telomere length of juvenile lizards. Warming conditions did not induce carry-over effects in terms of altered growth rate or physiology but resulted in increased mortality risk in the later life. Intriguingly, telomere shortening in young individuals was associated with mortality risk later in life. This study improves our mechanistic understanding of how global warming impacts on ectotherms' life-history traits, which encourages the inclusion of physiological information in assessing species vulnerability to climate change.
The authors exposed lizards (Eremias multiocellata) to climate warming from juvenile to adult stages to identify how climate warming affects animal survival. They found that climate warming enhanced juvenile growth, but induced oxidative stress, shortened telomere length, and therefore reduced survival. Display omitted
•Climate warming enhanced early-life growth, induced oxidative stress.•Climate warming shortened early-life telomere length.•Telomere shortening in early life predicted the low survival later in life.
Climate change often includes increases in the occurrence of extreme environmental events. Among these, heatwaves affect the pace of life and performance of wildlife, particularly ectothermic ...animals, owing to their low thermoregulatory abilities. However, the underlying mechanisms by which this occurs remain unclear. Evidence shows that heatwaves alter the redox balance of ectotherms, and oxidative stress is a major mediator of life-history trade-offs. Therefore, oxidative stress may mediate the effect of extreme thermal conditions on the life histories of ectotherms. To test this hypothesis, a 2 × 2 experiment was conducted to manipulate the redox balance (through a mitochondrial uncoupler that alleviates oxidative stress) of the desert toad-headed agama (
Phrynocephalus przewalskii
) exposed to heatwave conditions. We recorded lizard growth and survival rates and quantified their redox and immune statuses. In control lizards (unmanipulated redox balance), heatwave conditions decreased growth and survival and induced oxidative damage and immune responses. By contrast, lizards with alleviated oxidative stress showed close-to-normal growth, survival, and immune status when challenged with heatwaves. These results provide mechanistic insight into the role of oxidative stress in mediating the effects of extreme temperatures on ectothermic vertebrates, which may have major eco-evolutionary implications.
Zirconium-based metal-organic frameworks (Zr-MOFs) with periodic Lewis acidic nodes have demonstrated impressive catalytic activity in the hydrolysis of organophosphorus nerve agents. Nevertheless, ...the powdered form of Zr-MOFs and the necessity of a base-buffered aqueous solution during the catalytic reaction pose significant challenges to their practical utilization. In this study, we demonstrate the efficient hydrolysis of an organophosphorus nerve agent simulant, dimethyl-4-nitrophenyl phosphate (DMNP), in both pure water and the solid phase under high humidity conditions, catalyzed by a membrane material. This material, denoted as Im@MOF-808/PVDF, was synthesized through the integration of MOF-808 particles onto PVDF membrane fibers, with imidazole (Im) molecular bases incorporated into the pores of MOF-808. Our findings emphasize the excellent flexibility and processability inherent in Im@MOF-808/PVDF. More notably, it exhibits exceptional catalytic performance in the hydrolysis of DMNP in pure water. Additionally, it demonstrates fair catalytic activity for solid-phase DMNP hydrolysis under high humidity conditions. These features position Im@MOF-808/PVDF as one of the most promising protective materials, showcasing substantial practical applicability.
Display omitted
•Im@MOF-808/PVDF was prepared by integrating MOF-808 particles onto PVDF membrane and adsorbing imidazole molecules into MOF-808 pores.•Im@MOF-808/PVDF exhibited much high catalytic activity toward the hydrolysis of nerve agent simulants in pure water.•Im@MOF-808 displayed considerable catalytic acitivity for solid-phase hydrolysis of nerve agent simulants.
Evaluating the effects of temperature variations on animals plays an important role in understanding the threat of climate warming. The effects of developmental temperature on offspring performance ...are critical in evaluating the effects of warming temperatures on the fitness of oviparous species, but the physiological and biochemical basis of this developmental plasticity is largely unknown. In this study, we incubated eggs of the turtle
at low (24 °C), medium (28 °C), and high (32 °C) temperatures, and evaluated the effects of developmental temperature on offspring fitness, and metabolic enzymes in the neck and limb muscles of hatchlings. The hatchlings from eggs incubated at the medium temperature showed better fitness-related performance (righting response and swimming capacity) and higher activities of metabolic enzymes (hexokinase, HK; lactate dehydrogenase, LDH) than hatchlings from the eggs incubated at high or low temperatures. In addition, the swimming speed and righting response were significantly correlated with the HK activities in limb (swimming speed) and neck (righting response) muscles, suggesting that the developmental plasticity of energy metabolic pathway might play a role in determining the way incubation temperature affects offspring phenotypes. Integrating the fitness-related performance and the activities of metabolic enzymes, we predict that the
from high latitude would not face the detrimental effects of climate warming until the average nest temperatures reach 32 °C.
Abstract Objectives To investigate the expression and function of CD74 in normal renal tissue and clear cell–renal cell carcinoma (ccRCC), as well as related renal tubule epithelial lines. We also ...analyzed the association between clinicopathological characteristics of ccRCCs and the expression levels of CD74. Methods Immunostaining of CD74 was performed in 107 patients' renal tissue and cell lines. We evaluated the association between clinicopathological characteristics of ccRCC and CD74 levels using image analysis. CD74 expression levels were also analyzed by Western blot. Lentivirus-mediated CD74 knockdown inhibited the growth and invasion, of ccRCC cell lines 786-O in vitro and in vivo. Cell proliferation, apoptosis, and invasion as well as HIF-1α pathway–related proteins, were estimated by Western blot. All experiments were repeated at least 3 times. Results Immunostaining and image analysis showed strong immunoreactions of CD74 in all patients' ccRCC tissue and malignant cell lines, while CD74 expression levels were associated with tumor grade ( P = 0.013). Western blot indicated that ccRCC tissue and malignant cell lines expressed higher levels of CD74 and hypoxia inducible factor 1α (HIF-1α) than adjacent normal renal tissue and normal cell HK-2. Vitro and vivo tests demonstrated that lentivirus-mediated CD74 knockdown inhibited the proliferation of ccRCC cell lines, induced G1/S arrest and apoptosis, and inhibited invasion. Inhibition of CD74 resulted in down-regulation of HIF-1α pathway proteins. Conclusions CD74 was overexpressed in human ccRCCs and associated with tumor grade, and inhibition of CD74 produced ccRCC proliferation arrest, induced apoptosis, and inhibited invasion, which impinged on HIF-1α pathway–related proteins. It might represent a potential therapeutic target for ccRCC.
Background Intersinus septal cell （ISSC） is not a very uncommon frontal recess cell. But it is poorly described in literature. The clinical significance of this anatomic variant still remains ...unclear. The purpose of this study was to clarify the anatomy, classification of ISSC and its clinical significance in Chinese subjects. Methods We prospectively identified ISSC in 200 consecutive subjects who had undergone computed tomography （CT） scans： 120 without frontal sinusitis （group 1 ） and 80 with frontal sinusitis （group 2）. The ISSC was classified into two types： Type ⅠISSC communicated with frontal sinuses, type Ⅱ ISSC communicated with frontal recess. The patients of frontal sinusitis had undergone functional endoscopic sinus surgery with the assistance of the classification of ISSC. Statistical analysis was performed to correlate the ISSC and its type to the presence of frontal sinusitis. Results The ISSC was obvious when reviewing the coronal and axial CT scans. Of the 200 CT scans reviewed, ISSC were present in 90 （45%）. Of the 120 scans in group 1, ISSC were present in 49 （41%）, among which type ⅠISSC was in 22 （18%） and type Ⅱ was in 27 （23%）. Of the 80 scans in group 2, ISSC was present in 41 （51%）, among which type Ⅰ ISSC was in 16 （20%） and typeⅡwas in 25 （31%）. There were no statistically significant differences about the frequency distribution of total ISSC, type Ⅰ and Ⅱ ISSC between group 1 and group 2. Conclusions The prevalence of ISSC was very high in Chinese patients. The classification of ISSC was helpful for surgeon to operate according to whether it communicated with frontal sinus or frontal recess. The type Ⅱ ISSC could be relatively easily removed from frontal recess.
