Genetically Encoded Lizard Color Divergence for Camouflage and Thermoregulation.

Local adaptation is critical in speciation and evolution, yet comprehensive studies on proximate and ultimate causes of local adaptation are generally scarce. Here, we integrated field ecological experiments, genome sequencing, and genetic verification to demonstrate both driving forces and molecular mechanisms governing local adaptation of body coloration in a lizard from the Qinghai-Tibet Plateau. We found dark lizards from the cold meadow population had lower spectrum reflectance but higher melanin contents than light counterparts from the warm dune population. Additionally, the colorations of both dark and light lizards facilitated the camouflage and thermoregulation in their respective microhabitat simultaneously. More importantly, by genome resequencing analysis, we detected a novel mutation in Tyrp1 that underpinned this color adaptation. The allele frequencies at the site of SNP 459# in the gene of Tyrp1 are 22.22% G/C and 77.78% C/C in dark lizards and 100% G/G in light lizards. Model-predicted structure and catalytic activity showed that this mutation increased structure flexibility and catalytic activity in enzyme TYRP1, and thereby facilitated the generation of eumelanin in dark lizards. The function of the mutation in Tyrp1 was further verified by more melanin contents and darker coloration detected in the zebrafish injected with the genotype of Tyrp1 from dark lizards. Therefore, our study demonstrates that a novel mutation of a major melanin-generating gene underpins skin color variation co-selected by camouflage and thermoregulation in a lizard. The resulting strong selection may reinforce adaptive genetic divergence and enable the persistence of adjacent populations with distinct body coloration.

Collective effects of rising average temperatures and heat events on oviparous embryos.

Survival of the immobile embryo in response to rising temperature is important to determine a species' vulnerability to climate change. However, the collective effects of 2 key thermal characteristics associated with climate change (i.e., rising average temperature and acute heat events) on embryonic survival remain largely unexplored. We used empirical measurements and niche modeling to investigate how chronic and acute heat stress independently and collectively influence the embryonic survival of lizards across latitudes. We collected and bred lizards from 5 latitudes and incubated their eggs across a range of temperatures to quantify population-specific responses to chronic and acute heat stress. Using an embryonic development model parameterized with measured embryonic heat tolerances, we further identified a collective impact of embryonic chronic and acute heat tolerances on embryonic survival. We also incorporated embryonic chronic and acute heat tolerance in hybrid species distribution models to determine species' range shifts under climate change. Embryos' tolerance of chronic heat (T-chronic) remained consistent across latitudes, whereas their tolerance of acute heat (T-acute) was higher at high latitudes than at low latitudes. Tolerance of acute heat exerted a more pronounced influence than tolerance of chronic heat. In species distribution models, climate change led to the most significant habitat loss for each population and species in its low-latitude distribution. Consequently, habitat for populations across all latitudes will shift toward high latitudes. Our study also highlights the importance of considering embryonic survival under chronic and acute heat stresses to predict species' vulnerability to climate change.

Efectos colectivos del aumento de las temperaturas promedio y los eventos de calor en embriones ovíparos Resumen La supervivencia de los embriones inmóviles en respuesta al incremento de temperatura es importante para determinar la vulnerabilidad de las especies al cambio climático. Sin embargo, los efectos colectivos de dos características térmicas claves asociadas con el cambio climático (i. e., aumento de temperatura promedio y eventos de calor agudo) sobre la supervivencia embrionaria permanecen en gran parte inexplorados. Utilizamos mediciones empíricas y modelos de nicho para investigar cómo el estrés térmico crónico y agudo influye de forma independiente y colectiva en la supervivencia embrionaria de los lagartos en todas las latitudes. Recolectamos y criamos lagartos de cinco latitudes e incubamos sus huevos en un rango de temperaturas para cuantificar las respuestas específicas de la población al estrés por calor crónico y agudo. Posteriormente, mediante un modelo de desarrollo embrionario parametrizado con mediciones de tolerancia embrionaria al calor, identificamos un impacto colectivo de las tolerancias embrionarias al calor agudo y crónico en la supervivencia embrionaria. También incorporamos la tolerancia embrionaria crónica y aguda al calor en modelos de distribución de especies híbridas para determinar los cambios de distribución de las especies bajo el cambio climático. La tolerancia embrionaria al calor crónico (T­crónico) permaneció constante, mientras que la tolerancia al calor agudo (T­agudo) fue mayor en latitudes altas que en latitudes bajas. La tolerancia al calor agudo ejerció una influencia más pronunciada que la tolerancia al calor crónico. En los modelos de distribución de especies, el cambio climático provocó la pérdida de hábitat más significativa para cada población y especie en su distribución de latitudes bajas. En consecuencia, el hábitat para poblaciones en todas las latitudes se desplazará a latitudes altas. Nuestro estudio también resalta la importancia de considerar la supervivencia embrionaria bajo estrés térmico crónico y agudo para predecir la vulnerabilidad de las especies al cambio climático.

Taurine Stimulates AMP-Activated Protein Kinase and Modulates the Skeletal Muscle Functions in Rats via the Induction of Intracellular Calcium Influx.

Taurine (2-aminoethanesulfonic acid) is a free amino acid abundantly found in mammalian tissues. Taurine plays a role in the maintenance of skeletal muscle functions and is associated with exercise capacity. However, the mechanism underlying taurine function in skeletal muscles has not yet been elucidated. In this study, to investigate the mechanism of taurine function in the skeletal muscles, the effects of short-term administration of a relatively low dose of taurine on the skeletal muscles of Sprague-Dawley rats and the underlying mechanism of taurine function in cultured L6 myotubes were investigated. The results obtained in this study in rats and L6 cells indicate that taurine modulates the skeletal muscle function by stimulating the expression of genes and proteins associated with mitochondrial and respiratory metabolism through the activation of AMP-activated protein kinase via the calcium signaling pathway.

Temperate and tropical lizards are vulnerable to climate warming due to increased water loss and heat stress.

Climate warming has imposed profound impacts on species globally. Understanding the vulnerabilities of species from different latitudinal regions to warming climates is critical for biological conservation. Using five species of Takydromus lizards as a study system, we quantified physiological and life-history responses and geography range change across latitudes under climate warming. Using integrated biophysical models and hybrid species distribution models, we found: (i) thermal safety margin is larger at high latitudes and is predicted to decrease under climate warming for lizards at all latitudes; (ii) climate warming will speed up embryonic development and increase annual activity time of adult lizards, but will exacerbate water loss of adults across all latitudes; and (iii) species across latitudes are predicted to experience habitat contraction under climate warming due to different limitations-tropical and subtropical species are vulnerable due to increased extremely high temperatures, whereas temperate species are vulnerable due to both extremely high temperatures and increased water loss. This study provides a comprehensive understanding of the vulnerability of species from different latitudinal regions to climate warming in ectotherms, and also highlights the importance of integrating environmental factors, behaviour, physiology and life-history responses in predicting the risk of species to climate warming.

Effects of climate and human activity on the current distribution of amphibians in China.

In China, as elsewhere, amphibians are highly endangered. Anthropogenic environmental change has affected the distribution and population dynamics of species, and species distributions at a broad scale are strongly driven by climate and species' ability to disperse. Yet, current knowledge remains limited on how widespread human activity affects the distribution patterns of amphibians in China and whether this effect extends beyond climate. We compiled a relatively comprehensive database on the distribution of 196 amphibian species in China from the literature, public databases, and field data. We obtained 25,826 records on almost 50% of known species in China. To test how environmental factors and human activities influence the current distribution of amphibians (1960-1990), we used range filling, which is species realized ranges relative to their potential climate distribution. We used all species occurrence records to represent realized range and niche models to predict potential distribution range. To reduce uncertainty, we used 3 regression methods (beta regression, generalized boosted regression models, and random forest) to test the associations of species range filling with human activity, climate, topography, and range size. The results of the 3 approaches were consistent. At the species level, mean annual precipitation (climate) had the most effect on spatial distribution pattern of amphibians in China, followed by range size. Human activity ranked last. At the spatial level, mean annual precipitation remained the most important factor. Regions in southeastern of China that are currently moist supported the highest amphibian diversity, but were predicted to experience a decline in precipitation under climate change scenarios. Consequently, the distributions of amphibians will likely shift to the northwest in the future, which could affect future conservation efforts.

En China, como en todos lados, los anfibios están gravemente en peligro. El cambio ambiental antropogénico ha afectado la distribución y dinámica poblacional de especies, y la distribución de especies a gran escala están muy influidas por el clima y la habilidad de dispersión de las especies. Sin embargo, el conocimiento actual sigue siendo limitado sobre cómo la actividad humana generalizada afecta a los patrones de distribución de anfibios en China y si este efecto se extiende más allá del clima. A partir de literatura, bases de datos públicas y datos de campo, integramos una base datos relativamente completa sobre la distribución de 196 especies de anfibios en China. Obtuvimos 25,826 registros de casi 50% de las especies conocidas en China. Para probar cómo los factores ambientales y las actividades humanas influyen en la distribución actual de anfibios (1960-1990), utilizamos la ocupación de rango, que contrasta los rangos de distribución observada de las especies en relación con su distribución climática potencial. Utilizamos los registros de ocurrencia de todas las especies para representar el rango observado y modelos de nicho para predecir el rango de distribución potencial. Para reducir la incertidumbre, utilizamos 3 métodos de regresión (regresión beta, modelos de regresión acelerada generalizada y bosque aleatorio) para probar las asociaciones de la ocupación de rango de especies con la actividad humana, clima, topografía y extensión de rango. Los resultados de los tres métodos fueron consistentes. A nivel de especie, la precipitación media anual (clima) tuvo el mayor efecto sobre el patrón de distribución de anfibios en China, seguida por la extensión del rango. La actividad humana ocupó el último lugar. A nivel espacial, la precipitación media anual siguió como el factor más importante. Las regiones en el sureste de China que aun son húmedas sostuvieron la mayor diversidad de anfibios, pero se pronosticó que la precipitación declinará bajo escenarios de cambio climático. Consecuentemente, la distribución de anfibios muy probablemente cambiará hacia el noreste, lo cual podría afectar esfuerzos futuros de conservación.

Electroactive Hydroxyapatite/Carbon Nanofiber Scaffolds for Osteogenic Differentiation of Human Adipose-Derived Stem Cells.

Traditional bone defect treatments are limited by an insufficient supply of autologous bone, the immune rejection of allogeneic bone grafts, and high medical costs. To address this medical need, bone tissue engineering has emerged as a promising option. Among the existing tissue engineering materials, the use of electroactive scaffolds has become a common strategy in bone repair. However, single-function electroactive scaffolds are not sufficient for scientific research or clinical application. On the other hand, multifunctional electroactive scaffolds are often complicated and expensive to prepare. Therefore, we propose a new tissue engineering strategy that optimizes the electrical properties and biocompatibility of carbon-based materials. Here, a hydroxyapatite/carbon nanofiber (HAp/CNF) scaffold with optimal electrical activity was prepared by electrospinning HAp nanoparticle-incorporated polyvinylidene fluoride (PVDF) and then carbonizing the fibers. Biochemical assessments of the markers of osteogenesis in human adipose-derived stem cells (h-ADSCs) cultured on HAp/CNF scaffolds demonstrate that the material promoted the osteogenic differentiation of h-ADSCs in the absence of an osteogenic factor. The results of this study show that electroactive carbon materials with a fibrous structure can promote the osteogenic differentiation of h-ADSCs, providing a new strategy for the preparation and application of carbon-based materials in bone tissue engineering.

Effects of long-term taurine supplementation on age-related changes in skeletal muscle function of Sprague-Dawley rats.

Taurine (2-aminoethanesulfonic acid) is a free amino acid found abundantly in mammalian tissues. Increasing evidence suggests that taurine plays a role in the maintenance of skeletal muscle function and increase of exercise capacity. Most energy drinks contain this amino acid; however, there is insufficient research on the effects of long-term, low-dose supplementation of taurine. In this study, we investigated the effects of long-term administration of taurine at low doses on aging in rodents. In Experiment 1, we examined age-related changes in aging Sprague-Dawley (SD) rats (32-92 weeks old) that O2 consumption and spontaneous activity decreased significantly with aging. In Experiment 2, we examined the effects of long-term (21-week) administration of taurine on healthy aging SD rats. SD rats were stabilized for 32-34 weeks and divided into three groups, administrated water (control), 0.5% taurine (25 mg/kg  body weight (BW)/day), or 1% taurine (50 mg/kg  BW/day) from age 34 to 56 weeks (5 days/week, 5 mL/kg BW). Our findings suggest that long-term administration of taurine at relatively low dose could attenuate the age-related decline in O2 consumption and spontaneous locomotor activity. Upon intestinal absorption, taurine might modulate age-related changes in respiratory metabolism and skeletal muscle function via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), succinate dehydrogenase (SDH), cytochrome c (Cycs), myocyte enhancer factor 2A (MEF2A), glucose transporter 4 (GLUT4), and myoglobin, which are regulated by the activation of AMP-activated protein kinase (AMPK). This article examines the mechanism underlying the effects of taurine on age-related changes, which may have potential clinical implications.

A reciprocal egg-swap experiment reveals sources of variation in developmental success among populations of a desert lizard.

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.

Adaptive responses of the embryos of birds and reptiles to spatial and temporal variations in nest temperatures.

Natural nests of egg-laying birds and reptiles exhibit substantial thermal variation, at a range of spatial and temporal scales. Rates and trajectories of embryonic development are highly sensitive to temperature, favouring an ability of embryos to respond adaptively (i.e. match their developmental biology to local thermal regimes). Spatially, thermal variation can be significant within a single nest (top to bottom), among adjacent nests (as a function of shading, nest depth etc.), across populations that inhabit areas with different weather conditions, and across species that differ in climates occupied and/or nest characteristics. Thermal regimes also vary temporally, in ways that generate differences among nests within a single population (e.g. due to seasonal timing of laying), among populations and across species. Anthropogenic activities (e.g. habitat clearing, climate change) add to this spatial and temporal diversity in thermal regimes. We review published literature on embryonic adaptations to spatio-temporal heterogeneity in nest temperatures. Although relatively few taxa have been studied in detail, and proximate mechanisms remain unclear, our review identifies many cases in which natural selection appears to have fine-tuned embryogenesis to match local thermal regimes. Developmental rates have been reported to differ between uppermost versus lower eggs within a single nest, between eggs laid early versus late in the season, and between populations from cooler versus warmer climates. We identify gaps in our understanding of thermal adaptations of early (embryonic) phases of the life history, and suggest fruitful opportunities for future research.

Anticipatory parental effects in a subtropical lizard in response to experimental warming.

Parental effects may produce adaptive or maladaptive plasticity that either facilitates persistence or increases the extinction risk of species and populations in a changing climate. However, empirical evidence of transgenerational adaptive plastic responses to climate change is still scarce. Here we conducted thermal manipulation experiments with a factorial design in a Chinese lacertid lizard (Takydromus septentrionalis) to identify the fitness consequences of parental effects in response to climate warming. Compared to present climate conditions, a simulated warming climate significantly advanced the timing of oviposition, depressed the immune capability of post-partum females, and decreased the hatching success of embryos, but did not affect female reproductive output (clutch size and egg mass). These results indicate that maternal warming negatively affects female health, and embryonic hatchability. More interestingly, we found that offspring from parents exposed to warming environments survived well under a simulated warming climate, but not under a present climate scenario. Accordingly, our study demonstrates anticipatory parental effects in response to a warming climate in an ectothermic vertebrate. However, the fitness consequences of this parental effect will depend on future climate change scenarios.

Phenotypic plasticity may help lizards cope with increasingly variable temperatures.

Temperature variability is predicted to increase in the coming century due to climate change. However, the biological impact of increased temperature variability on animals remains largely unexplored. Here, we experimentally exposed gravid viviparous lizards (Eremias multiocellata) to two thermal environments [constant daily maximum (CDM) versus variable daily maximum (VDM) treatment with the same average temperature] to address maternal and offspring responses to increased variability in ambient temperature. Females from the VDM treatment delayed parturition, but produced similar litter sizes and litter masses as did CDM females. Offspring from the VDM treatment selected higher body temperatures, had higher metabolic rates and higher growth rates, and grew to a similar size as those from the CDM treatment despite having a shorter growth period prior to hibernation. Therefore, phenotypic plasticity may be critical for lizards to respond effectively to climate change, and its role in responding to increasingly variable temperatures warrants further attention.

Thyroid hormone modulates offspring sex ratio in a turtle with temperature-dependent sex determination.

The adaptive significance of temperature-dependent sex determination (TSD) has attracted a great deal of research, but the underlying mechanisms by which temperature determines the sex of a developing embryo remain poorly understood. Here, we manipulated the level of a thyroid hormone (TH), triiodothyronine (T3), during embryonic development (by adding excess T3 to the eggs of the red-eared slider turtle Trachemys scripta, a reptile with TSD), to test two competing hypotheses on the proximate basis for TSD: the developmental rate hypothesis versus the hormone hypothesis Exogenous TH accelerated embryonic heart rate (and hence metabolic rate), developmental rate, and rates of early post-hatching growth. More importantly, hyperthyroid conditions depressed expression of Cyp19a1 (the gene encoding for aromatase) and levels of oestradiol, and induced more male offspring. This result is contrary to the direction of sex-ratio shift predicted by the developmental rate hypothesis, but consistent with that predicted by the hormone hypothesis Our results suggest an important role for THs in regulating sex steroid hormones, and therefore, in affecting gonadal sex differentiation in TSD reptiles. Our study has implications for the conservation of TSD reptiles in the context of global change because environmental contaminants may disrupt the activity of THs, and thereby affect offspring sex in TSD reptiles.

Identification potential biomarkers in pulmonary tuberculosis and latent infection based on bioinformatics analysis.

BACKGROUND: The study aimed to identify the potential biomarkers in pulmonary tuberculosis (TB) and TB latent infection based on bioinformatics analysis. METHODS: The microarray data of GSE57736 were downloaded from Gene Expression Omnibus database. A total of 7 pulmonary TB and 8 latent infection samples were used to identify the differentially expressed genes (DEGs). The protein-protein interaction (PPI) network was constructed by Cytoscape software. Then network-based neighborhood scoring analysis was performed to identify the important genes. Furthermore, the functional enrichment analysis, correlation analysis and logistic regression analysis for the identified important genes were performed. RESULTS: A total of 1084 DEGs were identified, including 565 down- and 519 up-regulated genes. The PPI network was constructed with 446 nodes and 768 edges. Down-regulated genes RIC8 guanine nucleotide exchange factor A (RIC8A), basic leucine zipper transcription factor, ATF-like (BATF) and microtubule associated monooxygenase, calponin LIM domain containing 1 (MICAL1) and up-regulated genes ATPase, Na+/K+ transporting, alpha 4 polypeptide (ATP1A4), histone cluster 1, H3c (HIST1H3C), histone cluster 2, H3d (HIST2H3D), histone cluster 1, H3e (HIST1H3E) and tyrosine kinase 2 (TYK2) were selected as important genes in network-based neighborhood scoring analysis. The functional enrichment analysis results showed that these important DEGs were mainly enriched in regulation of osteoblast differentiation and nucleoside triphosphate biosynthetic process. The gene pairs RIC8A-ATP1A4, HIST1H3C-HIST2H3D, HIST1H3E-BATF and MICAL1-TYK2 were identified with high positive correlations. Besides, these genes were selected as significant feature genes in logistic regression analysis. CONCLUSIONS: The genes such as RIC8A, ATP1A4, HIST1H3C, HIST2H3D, HIST1H3E, BATF, MICAL1 and TYK2 may be potential biomarkers in pulmonary TB or TB latent infection.

Heat shock protein expression enhances heat tolerance of reptile embryos.

The role of heat shock proteins (HSPs) in heat tolerance has been demonstrated in cultured cells and animal tissues, but rarely in whole organisms because of methodological difficulties associated with gene manipulation. By comparing HSP70 expression patterns among representative species of reptiles and birds, and by determining the effect of HSP70 overexpression on embryonic development and hatchling traits, we have identified the role of HSP70 in the heat tolerance of amniote embryos. Consistent with their thermal environment, and high incubation temperatures and heat tolerance, the embryos of birds have higher onset and maximum temperatures for induced HSP70 than do reptiles, and turtles have higher onset and maximum temperatures than do lizards. Interestingly, the trade-off between benefits and costs of HSP70 overexpression occurred between life-history stages: when turtle embryos developed at extreme high temperatures, HSP70 overexpression generated benefits by enhancing embryo heat tolerance and hatching success, but subsequently imposed costs by decreasing heat tolerance of surviving hatchlings. Taken together, the correlative and causal links between HSP70 and heat tolerance provide, to our knowledge, the first unequivocal evidence that HSP70 promotes thermal tolerance of embryos in oviparous amniotes.

Embryonic oxygen enhances learning ability in hatchling lizards.

INTRODUCTION: Producing smart offspring is an important fitness trait; individuals with enhanced cognitive ability should be more adept at responding to complex environmental demands. Cognitive ability can be influenced by conditions experienced during embryonic development. Although oxygen is necessary for embryonic development, availability can be limited within the nest environment because of substrate type, hydric conditions, and temperature. We do not yet understand, however, whether oxygen availability during embryonic development influences offspring fitness, especially cognitive ability. To address this question we incubated Mongolian Racerunner lizard (Eremias argus) eggs under hypoxic (12% O2), normoxic (21% O2), and hyperoxic conditions (30% O2). RESULTS: Hypoxia not only slowed hatching time, but also resulted in constrained cognitive ability relative to hatchlings experiencing normoxic or hyperoxic incubation conditions. Oxygen did not influence hatching success, body size or sprint speed of hatchlings. CONCLUSIONS: Oxygen availability during embryonic development has important influences on incubation duration and cognitive ability of hatchling lizards. This study provides the first evidence that oxygen availability during embryonic development can modify cognitive ability of oviparous reptiles.

Climate warming has divergent physiological impacts on sympatric lizards.

Climate warming is expected to affect the vulnerability of sympatric species differentially due to their divergent traits, but the underlying physiological mechanisms of those impacts are poorly understood. We conducted field warming experiments (present climate vs. warm climate) using open-top chambers to determine the effects of climate warming on active body temperature, oxidative damage, immune competence, growth and survival in two sympatric desert-dwelling lizards, Eremias multiocellata and Eremias argus from May 2019 to September 2020. Our climate warming treatment did not affect survival of the two species, but it did increase active body temperatures and growth rate in E. multiocellata compared to E. argus. Climate warming also induced greater oxidative damage (higher malondialdehyde content and catalase activity) in E. multiocellata, but not in E. argus. Further, climate warming increased immune competence in E. multiocellata, but decreased immune competence in E. argus, with regards to white blood cell counts, bacteria killing ability and relative expression of immunoglobulin M. Our results suggest that climate warming enhances body temperature, and thereby oxidative stress, immune competence and growth in E. multiocellata, but decreases immune competence of E. argus, perhaps as a cost of thermoregulation to maintain body temperatures under climate warming. The divergent physiological effects of climate warming on sympatric species may have profound ecological consequences if it eventually leads to changes in reproductive activities, population dynamics and community structure. Our study highlights the importance of considering interspecific differences in physiological traits when we evaluate the impact of climate warming on organisms, even for those closely-related species coexisting within the same geographical area.

How incubation temperature affects hatchling performance in reptiles: an integrative insight based on plasticity in metabolic enzyme.

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 Pelodiscus sinensis 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 P. sinensis from high latitude would not face the detrimental effects of climate warming until the average nest temperatures reach 32 °C.

The cyclin D1 (CCND1) G870A polymorphism and lung cancer susceptibility: a meta-analysis.

Several studies have investigated the association between Cyclin D1 (CCND1) G870A genetic polymorphism and lung cancer susceptibility, but the results were inconclusive. The aim of this meta-analysis was to summarize available evidence for such a relationship. The reviewers made use of MEDLINE, EMBASE, and BIOSIS databases. The relevant data were independently extracted by two reviewers. The odds ratio (OR) with 95% confidence interval (CI) was selected as the principal outcome measure. The heterogeneity test, the publication bias test, and the sensitivity analysis were performed. Overall, a total of 10 case-control studies were included. Our meta-analysis indicated that CCND1 G870A genetic polymorphism was a risk factor for lung cancer under homozygote model (OR = 1.18; 95% CI = 1.02, 1.37), recessive model (OR = 1.21; 95% CI = 1.03, 1.41), and allele model (OR = 1.11; 95% CI = 1.02, 1.21). In the subgroup analysis by source of ethnicity, a statistical increase of lung cancer risk was found among Asian groups for allele model (OR = 1.11; 95% CI = 1.01-1.22). The present meta-analysis suggests that CCND1 G870A polymorphism may be a risk factor for lung cancer. Besides, allele A may contribute to increased lung cancer risk.

Different mechanisms lead to convergence of reproductive strategies in two lacertid lizards (Takydromus wolteri and Eremias argus).

Life history traits may vary within and among species. Rarely, however, are both variations examined concurrently to identify the life history adaptation. We found that female body size, offspring number and size, and incubation period showed convergent evolution in two lacertid lizards (Takydromus wolteri and Eremias argus) that occur sympatrically in high-latitude and low-latitude localities. Females from the high-latitude population were larger and produced larger clutches than those from the low-latitude population. In both species, the incubation period was shorter for the high-latitude population than for the low-latitude population. However, the physiological mechanism underlying the shorter incubation period differed between the species. These results suggest that: (1) sympatric lizards may adopt similar reproductive strategies in response to their common environments, and (2) embryonic development of the two species follows different pathways for adaptation to low temperatures. This study highlights the importance of understanding the adaptive evolution of life history in response to environmental changes at the embryonic life stages.

Metabolic regulation reduces the oxidative damage of arid lizards in response to moderate heat events.

Climate warming poses a significant threat to species worldwide, particularly those inhabiting arid and semi-arid regions where extreme temperatures are increasingly prevalent. However, empirical studies investigating how moderate heat events affect the physiological processes of arid and semi-arid animals are largely scarce. To address this knowledge gap, we used an arid and semi-arid lizard species (Phrynocephalus przewalskii) as a study system. We manipulated thermal environments to simulate moderate heat events (43.5 ± 0.3°C during the heating period) for lizards and examined physiological and biochemical traits related to survival, metabolism, locomotion, oxidative stress, and telomere length. We found that the body condition and survival of the lizards were not significantly affected by moderate heat events, despite an increase in body temperature and a decrease in locomotion at high test temperatures were detected. Mechanistically, we found that the lizards exhibited down-regulated metabolic rates and enhanced activities of antioxidative enzymes, resulting in reduced oxidative damage and stable telomere length under moderate heat events. Based on these findings, which indicated a beneficial regulation of fitness by physiological and biochemical processes, we inferred that moderate heat events did not have a detrimental effect on the toad-headed agama, P. przewalskii. Overall, our research contributes to understanding the impacts of moderate heat events on arid and semi-arid species and highlights the adaptive responses and resilience exhibited by the toad-headed agama in the face of climate warming.