Wei-Guo Du

Chinese Academy of Sciences | CAS · Key Laboratory of Animal Ecology and Conservation Biology

Squamate reptiles exhibit two reproductive modes: oviparity and viviparity. Existing large‐scale studies suggest that viviparous species are more vulnerable to climate warming based on viviparous species occupying relatively colder environments, which are predicted to decline in availability under climate warming. However, oviparous and viviparous...

Adaptations of post‐hatching animals have attracted far more study than have embryonic responses to environmental challenges, but recent research suggests that we have underestimated the complexity and flexibility of embryos. We advocate a dynamic view of embryos as organisms capable of responding – on both ecological and evolutionary timescales –...

Patterns in functional diversity of organisms at large spatial scales can provide insight into possible responses to future climate change, but it remains a challenge to link large-scale patterns at the population or species level to their underlying physiological mechanisms at the individual level. The climate variability hypothesis predicts that...

The purging of deleterious alleles has been hypothesized to mitigate inbreeding depression, but its effectiveness in endangered species remains debatable. To understand how deleterious alleles are purged during population contractions, we analyzed genomes of the endangered Chinese crocodile lizard (Shinisaurus crocodilurus), which is the only survi...

Temperature sensing is essential for the survival of living organisms. Some reptile embryos can reposition themselves within the egg to seek optimal temperatures, but the molecular sensors involved in this temperature detection remain unknown. Here, we show that such thermotaxic behavior is directly determined by the activation of two heat-sensitiv...

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...

Reptile embryos can move inside eggs to seek optimal thermal conditions, falsifying the traditional assumption that embryos are simply passive occupants within their eggs. However, the adaptive significance of this thermoregulatory behavior remains a contentious topic. Here we demonstrate that behavioral thermoregulation by turtle embryos shortened...

Most amniote genomes are diploid, moderate in size (approximately 1-6 Gbp), and contain a large proportion of repetitive sequences. The development of next-generation sequencing technology, especially the emergence of high-fidelity (HiFi) long-read data, has made it feasible to resolve high-quality genome assembly for non-model species efficiently....

A range of abiotic parameters within a reptile nest influence the viability and attributes (including sex, behaviour and body size) of hatchlings that emerge from that nest. As a result of that sensitivity, a reproducing female can manipulate the phenotypic attributes of her offspring by laying her eggs at times and in places that provide specific...

As biodiversity faces significant threats from habitat loss and climate change, we developed a biophysical modeling framework to study their impact on a desert lizard's activity and microhabitat selection. We predict that lizards will be active in open habitat during winter, but rocks are critical for their summer activity. Under climate change, ho...

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 war...

To meet the challenge of biodiversity loss and reach the targets of the proposed Post-2020 Global Biodiversity Framework, the Chinese government updated the list of national key protected wildlife in 2021 and has been continually expanding the protected areas (PAs). However, the status of protected wildlife in PAs remains unclear. In this study, we...

Protected Areas (PAs) are the cornerstone of biodiversity conservation. Here, we collated distributional data for >14,000 (~70% of) species of amphibians and reptiles (herpetofauna) to perform a global assessment of the conserva- tion effectiveness of PAs using species distribution models. Our analyses reveal that >91% of herpetofauna species are c...

Ongoing climate change has profoundly affected global biodiversity, but its impacts on populations across elevations remain understudied. Using a mechanistic niche model incorporating species traits, we predicted ecophysiological responses (activity times, oxygen consumption and evaporative water loss) for lizard populations at high-elevation (< 36...

Background Although the extreme environmental adaptation of organisms is a hot topic in evolutionary biology, genetic adaptation to high-altitude environment remains poorly characterized in ectothermic animals. Squamates are among the most diverse terrestrial vertebrates, with tremendous ecological plasticity and karyotype diversity, and are a uniq...

Climate warming can substantially impact embryonic development and juvenile growth in oviparous species. Estimating the overall impacts of climate warming on oviparous reproduction is difficult because egg-laying events happen throughout the reproductive season. Successful egg-laying requires the completion of embryonic development as well as hatch...

Identifying how reproductive strategies such as the trade-off between clutch size versus egg mass vary with elevational gradients is essential for our understanding of life-history evolution. We studied lacertid lizards (Eremias argus) in China, from six populations at different altitudes, to assess elevational variation in reproductive strategy. W...

Thickness reduction or loss of the calcareous eggshell is one of major phenotypic changes in the transition from oviparity to viviparity. Whether the reduction of eggshells in viviparous squamates is associated with specific gene losses is unknown. Taking advantage of a newly generated high‐quality genome of the viviparous Chinese crocodile lizard...

Colour plays a key role in animal social communication including as an indicator of individual quality. Using spectrophotometry, we examined colour variation in the throat and venter of the crocodile lizard (Shinisaurus crocodilurus), an endangered species native to southern China and northern Vietnam. We detected two broad colour variants, individ...

The body color of aquatic products is a key indicator that aquaculture practitioners use to evaluate health status and consumers use to judge quality. Carotenoids are natural pigments that are mainly pigmented compounds responsible for red, yellow, and orange coloration. They have important functions, such as immune and antioxidant modulation. Rece...

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 a...

Microhabitats provide ecological and physiological benefits to animals, sheltering them from predation and extreme temperatures and offering an additional supply of water and food. However, most studies have assumed no energetic costs of searching for microhabitats or moving between them, or considered how the availability of microhabitats may affe...

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...

Maternal egg-caring behavior can often be observed in oviparous scincid lizards. The expression of such behavior is predictably affected by the trade-off between its resultant costs and benefits for mothers and/or offspring, which has been investigated in only a few scincid species. Here, post-ovipositional Plestiodon chinensis females were treated...

Heat tolerance at the immobile embryonic stage is expected to be critical in determining species vulnerability to climate change. However, how the mean and developmental plasticity of embryonic heat tolerance vary geographically, and how these geographic variations affect species’ vulnerability under climate change remain unknown. We experimentally...

Under ongoing climate warming, how embryos of oviparous species tolerate the extreme heat events geographically is critical to predict the vulnerabilities of organisms. We experimentally incubated eggs at five temperatures (24, 26, 28, 30, 32, and 34℃) and determined the embryonic acute heat tolerance (EAHT) of the northern grass lizard, Takydromus...

While the effects of incubation environment on embryonic development and offspring traits have been extensively studied in oviparous vertebrates, studies into how genetic inheritance (population origin), maternal effects, and incubation environment interact to produce varying phenotypes, are rare. To elucidate the interactive role of those three fa...

The molecular mechanism of temperature-dependent sex determination (TSD) in reptiles has been drawn great interest from biologists for several decades. However, which genetic factors are essential for TSD remain elusive, especially for the female sex determination process. Cyp19a1 , encodes an enzyme of aromatase catalyzing the conversion of testos...

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 eg...

Montane reptiles are predicted to move to higher elevations in response to climate warming. However, whether upwards-shifting reptiles will be physiologically constrained by hypoxia at higher elevations remains unknown. We investigated the effects of hypoxic conditions on preferred body temperatures (Tpref) and thermal tolerance capacity of a monta...

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 under...

Despite the importance of maternally-selected nests in shaping offspring phenotypes, our understanding of how the nest environment affects embryonic development and offspring traits of most non-avian reptiles is rather limited largely due to the logistical difficulty in locating their nests. To identify the relative contributions of environmental [...

Understanding the factors that may affect behavioural thermoregulation of endangered reptiles is important for their conservation because thermoregulation determines body temperatures and in turn physiological functions of these ectotherms. Here we measured seasonal variation in operative environmental temperature (Te), body temperature (Tb), and m...

Captivity is an important measure for conservation of an endangered species, and it is becoming a hot topic in conservation biology, which integrates gut microbiota and endangered species management in captivity. As an ancient reptile, the crocodile lizard (Shinisaurus crocodilurus) is facing extreme danger of extinction, resulting in great signifi...

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, ther...

Sessile organisms with thermally sensitive developmental trajectories are at high risk from climate change. For example, oviparous reptiles with temperature-dependent sex determination (TSD) may experience strong (potentially disastrous) shifts in offspring sex ratio if reproducing females are unable to predict incubation conditions at the time of...

Captive breeding is an important conservation measure that may restore and enhance wild populations of rare and endangered species. Multiple anthropogenic hazards have brought the crocodile lizard, Shinisaurus crocodilurus, to the brink of extinction. We initiated a captive breeding program and quantified female reproductive traits, including repro...

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...

Background: Ectothermic animals living in cold (high latitude or high elevation) regions are predicted to grow slower due to limited thermal opportunities for activity and food resources than those living in warm regions. However, the Qinghai toad-headed lizards (Phrynocephalus vlangalii) grow faster and reach a larger adult size at a high-elevati...

A major goal of seasonal biology is to understand how selection on phenology and the physiological niche interact. In oviparous species, fitness variation across the growing season suggests that phenological shifts will alter selective environments experienced by embryos. We hypothesize that physiology could become co‐adapted with phenology; such t...

How temperature influences development has direct relevance to ascertaining the impact of climate change on natural populations. Reptiles have served as empirical models for understanding how the environment experienced by embryos can influence phenotypic variation, including sex ratio, phenology and survival. Such an understanding has important im...

Scientific interest in developmental plasticity spans many disciplines, and research on reptiles has provided many insights into this field. We highlight these contributions, review the field's history, and introduce the special issue on this topic .

Early life environments shape phenotypic development in important ways that can lead to long-lasting effects on phenotype and fitness. In reptiles, one aspect of the early environment that impacts development is temperature (termed 'thermal developmental plasticity'). Indeed, the thermal environment during incubation is known to influence morpholog...

The vulnerability of species to climate warming varies along latitudinal and elevational clines, but how sympatric species vary in vulnerability to climate warming remains largely unknown. We experimentally simulated nest temperatures of two sympatric lizards with divergent microhabitat preferences (Phrynocephalus przewalskii and Eremias argus), un...

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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 va...

Aim The evolution of viviparity in squamate reptiles has attracted considerable scientific attention since the beginning of last century. The cold‐climate hypothesis posits that cold regions favor viviparity (and therefore the incidence of viviparous squamates is increased in these regions) because viviparous females can use thermoregulatory behavi...

The debate about behavioral thermoregulation inside reptile eggs centers on the frequency (and hence, biological significance) of the phenomenon, not about its validity. Both sides of the debate agree that large eggs in shallow nests laid in sun‐exposed soil will experience clines in mean temperature and (especially) diel thermal variance; that emb...

Despite widespread temperature-dependent sex determination (TSD) in reptiles, it is still unclear how the molecular network responds to temperature variation and drives the sexual fate. Profiling of sex-related genes is the first step in understanding the sex determination system in reptiles. In this study, we cloned the full-length coding sequence...

Obligate brood parasites have evolved unusually thick-shelled eggs, which are hypothesized to possess a variety of functions such as resistance to puncture ejection by their hosts. In this study, we tested the hypothesis that obligate brood parasites lay unusually thick-shelled eggs to retain more heat for the developing embryo and thus contribute...

It is critical for avian brood parasites (such as cuckoos) that their eggs hatch earlier than those of their hosts. However, the physiological mechanisms underlying this phenomenon (other than internal incubation) remain largely unstudied. Here, we tested the validity of two potentially mutually compatible hypotheses: that lower energy reserve and...

Body size is directly linked to key life history traits such as growth, fecundity, and survivorship. Identifying the causes of body size variation is a critical task in ecological and evolutionary research. Body size variation along altitudinal gradients has received considerable attention; however, the underlying mechanisms are poorly understood....

Many oviparous animals construct well-designed nests to provide relatively favourable conditions for their eggs and hatchlings, but the direct evidence that nest structure can determine their reproductive success is insufficient. In the present study, we explored the structure of nests and its effect on nest environments and reproductive success in...

The thermal environment of embryos differs significantly along a latitudinal cline, and the mechanism by which embryos respond to this geographic temperature variation has attracted increasing attention recently. Here, we carried out a common-garden experiment of egg incubation at two fluctuating temperature regimes to elucidate the latitudinal pat...

How ectotherms exploit thermal resources has important implications for their habitat utilization and thermal vulnerability to climate warming. To address this issue, we investigated thermal relations of three sympatric lizard species (Eremias argus, Eremias multiocellata, and Phrynocephalus przewalskii) in the desert steppe of Inner Mongolia, Chin...

1. The fitness consequence of maternal nest-site choice has attracted increasing scientific attention, but field studies identifying the long-term effects of nest-site choice on offspring survival and reproductive success are still rare in vertebrates. 2. To investigate the consequences of nest-site choice in lizards, we quantified the thermal and...

The response of embryos to unpredictable hypoxia is critical for successful embryonic development, yet there remain significant gaps in our understanding of such responses in reptiles with different types of eggshell. We experimentally generated external regional hypoxia by sealing either the upper- or bottom-half of the surface area of eggs in two...

Whether maternal effects are adaptive or not has been a long‐standing topic of discussion in evolutionary ecology. The effects of maternal diet on offspring have been addressed by several studies on diverse organisms, but results are typically conflicting or inconclusive. In this study, we conducted food manipulation experiments with a factorial de...

Food availability significantly affects an animal's energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species. In this study, we conducted food manipulation experiments in field enclosures to id...

Light is an environmental factor that is known to profoundly affect embryonic development in some oviparous vertebrates, but such effects are unstudied in reptiles. We investigated the light sensitivity of lizard embryos by examining the thickness and light transmittance of eggshells as well as the effect of light on embryonic development and hatch...

Extreme high temperatures are occurring more frequently with ongoing anthropogenic climate warming, but the experimental tests of the effects of high temperatures on terrestrial vertebrates in natural conditions are rare. In this study, we investigated the effects of extreme high temperatures on female reproduction and offspring traits of multi-oce...

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 (T 3), during embryonic development (by a...

Understanding community assembly is a fundamental goal of ecology and evolutionary biology, because it provides insight into how a given landscape changes in a synergistic fashion. With the current background of global environmental change, studies of how habitat alteration affects local communities often focus on species' responses to community-le...

Deltamethrin is a widespread environmental hormone with endocrine-disrupting properties, but its effect on embryonic development of reptiles is largely unexplored. We investigated the effects of deltamethrin on embryonic development and offspring traits in two turtle species, one with parchment-shelled eggs and the other with rigidshelled eggs. Del...

Identifying how developmental temperature affects the immune system is critical for understanding how ectothermic animals defend against pathogens and their fitness in the changing world. However, reptiles have received little attention regarding this issue. We incubated eggs at three ecologically relevant temperatures to determine how incubation t...

Developmental rate increases exponentially with increasing temperature in ectothermic animals, but the biochemical basis underlying this thermal dependence is largely unexplored. We measured mitochondrial respiration and metabolic enzyme activities of turtle embryos (Pelodiscus sinensis) incubated at different temperatures to identify the metabolic...

The sex determination mechanism for the Chinese soft-shelled turtle (Pelodiscus sinensis) is subject to controversy. Some populations have been shown to possess sex chromosomes and thus genotypic sex determination (GSD), while others were reported to exhibit temperature-dependent sex determination (TSD). To test whether TSD and GSD coexist in this...

Oxygen and temperature have previously been treated as different environmental stresses and studied separately in most cases. Although the oxygen–temperature interaction may provide new insight into proximate and evolutionary constraints on embryonic development and offspring fitness, it has rarely been studied in oviparous amniotes. We used a two-...

The effect of incubation temperature on embryonic development and offspring traits has been widely reported for many species. However, knowledge remains limited about how such effects vary across populations. Here, we investigated whether incubation temperature (26, 28, and 30 °C) differentially affects the embryonic development of Asian yellow pon...