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Nannizziopsis guarroi causes contagious dermatomycosis in lizards. Treatment failures are commonly encountered and may be related to the prolonged environmental persistence of this microbe. F10 SC, containing benzalkonium chloride and polyhexanide, is a commercially available disinfectant often used in management of reptile infections particularly by hobbyists and breeders. Three molecularly confirmed isolates of N. guarroi were aseptically collected into aqueous suspensions and diluted to 2 fungal concentrations. Each concentration of each isolate was exposed to 3 dilutions of F10 SC (1:20, 1:100, 1:500) for a 10-minute contact time based upon product label recommendations. Culture growth on standard potato-dextrose agar after 10 days of incubation was assessed for characteristic colony growth and cytology evaluation for fungal elements. The experimental design included control conditions as well as biological and technical replication. All control conditions grew characteristic fungal colonies with fungal elements visualized cytologically. Both concentrations of all 3 isolates exhibited no growth after contact with the highest concentration of the disinfectant (1:20) however fungal growth was evident after contact with the lowest concentration of disinfectant (1:500). Environments exposed and/or contaminated with N. guarroi can be effectively disinfected using F10 SC for a contact time of 10 minutes. Exposure to living tissue has not been evaluated and cannot be recommended at this time. Further work evaluating F10 SC disinfection against clinically relevant microbes should be pursued. [ABSTRACT FROM AUTHOR]

Leopard geckos (Eublepharis macularius) are a popular captive bred species of reptile in the exotic pet trade that are commonly seen for clinical presentations consistent with hypovitaminosis A. There has been a lack of antemortem diagnostics available for minimally invasive and appropriate diagnosis of this disease. Reference intervals for retinol have not been published or validated in leopard geckos or any closely related species. Plasma, with a sample volume of only 50 µl, from 40 healthy captive bred leopard geckos, 20 males and 20 females were analyzed using ultra-high-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) to determine plasma retinol concentrations. Using UPLC/MS analysis data was normally distributed and a reference interval for plasma retinol in the leopard gecko was 0.06 to 0.55µg/mL (0.01–0.08µmol/L). A mean of 0.31µg/mL with a lower limit 95% confidence interval being 0.03 to 0.10 µg/mL and upper limit of 0.52 to 0.59 µg/mL. No significant variations of plasma retinol were found based on gecko color morph, age or weight. Female leopard geckos had a slightly higher mean plasma retinol compared to males, but was not significantly different. This study will allow veterinary clinicians to better diagnose and treat hypovitaminosis A and to provide advice on dietary supplementation and dietary improvement for the leopard gecko and possibly other gecko species as well. In addition, these values can be used to design and evaluate other studies for nutritional needs of this species. Limitations of this study include only a single season of collection, no same time comparison to liver values, and the evaluation of only captive bred individuals. [ABSTRACT FROM AUTHOR]

LIZARD is a lightweight stream cipher designed by Hamann et al. in 2017 for power constrained devices. In this work, we have done cryptanalysis of LIZARD by improving modified Three Subset Division Property proposed by Hao et al. in EUROCRYPT 2020. We have improved Hao et al.'s attack model using the following methods — first we found a set of secret key bits (J) that are involved in the superpoly and then estimated the degree (d) of the superpoly using degree estimation strategy introduced by Q.Wang et al. in CRYPTO 2018. With the knowledge of J and d , we evaluate only those monomials with degree less than or equal to d. This improvement to Hao's attack model reduces the time complexity from 2 | I | + | J | to { 2 | I | ∗ ∑ i = 0 d | J | C i }. Further, since removing even number of trails do not have impact on the final result, we present a propagation reduction property which eliminates the even number of trails and this improves the algorithm efficiency too. Using the improved attack model we have recovered superpoly and key for the reduced initialization rounds 223 and 224. The time complexity to recover superpoly for round 223 is 2 112 and for round 224 it is 2 101. The time complexity for key recovery process is 2 119. [ABSTRACT FROM AUTHOR]

The endocrine system and particularly thyroid hormones regulate almost all physiological processes in a timely manner in all vertebrates, from fish to reptiles to mammals, so risk assessment of endocrine disrupting chemicals (EDCs) is extremely important given their persistent presence in all environmental matrices. Resorcinol, as well as nonylphenol, octylphenol, and bisphenol A, F, S, are non-Halogenated Phenolic (non-HPCs) Chemicals known as EDCs. Resorcinol is a particular example in that most studies are based exclusively on humans while animal studies are few and often inadequate. The aim of this study was to assess the effects of exposure to different doses of resorcinol on the thyroid gland of the lizard Podarcis siculus during different periods of the thyroid gland activity cycle. Our results showed histopathologic changes in thyroid (follicular cell height increase and colloid area decrease), a thyroid weight increase in combination with serum T 4 and T 3 decrease, serum TSH, TRH increase in male lizards treated with 0.8,3.9,13.1, and 36.9 mg/kg/d of resorcinol. Besides, we also investigated the impacts of resorcinol treatments on hepatic 5′ORD (type II) deiodinase and hepatic content of T 3 and T 4. Our findings showed that they are in agreement with in vivo in humans and in rodents data and therefore, resorcinol in reptiles may meet the WHO definition of ECDs. [Display omitted] • Resorcinol seriously compromises the thyroid gland. • Plasma T4 and T3 levels were significantly decreased in the resorcinol exposure. • HPT axis is correlated with the exposure of resorcinol. • Resorcinol exposure mainly disrupted hepatic dio 2 and T 4 and T 3 contents. [ABSTRACT FROM AUTHOR]

Vertebrate burrows serve as windows into the past, revealing the activities of various organisms and providing clues about their paleoenvironmental conditions. This study focuses on a vertebrate paleoburrow from the Três Barras Formation, Minas Gerais state, southeastern Brazil, aiming to detail and reconstruct aspects of the paleoclimatic conditions that acted in this area during the early Cretaceous within a predominantly eolian paleoenvironment. Through detailed analysis of the sedimentary facies and morphological examination of the burrow, this study suggests that the structure was likely produced by lungfish or lizards. It is located within proximal crevasse splay deposits interbedded with fine floodplain sediments, indicating periods of flooding in a meandering fluvial setting that developed in the marginal areas of the eolian system of the Três Barras Formation. Comparison with other paleoburrows from neighboring basins further enhances our understanding of the paleoenvironmental conditions during the early Cretaceous Period. These findings reinforce evidence of seasonality and suggest a period of intense humidity during the deposition of the Três Barras Formation, which had previously been interpreted as exclusively aeolian. • More humid than expected conditions are observed in the Três Barras Formation. • Vertebrate paleoburrows are important indicators of varying environmental conditions. • Meandering river zone is a refuge to lungfishes or lizards from early Cretaceous. • First paleoburrow from the early Cretaceous Três Barras Formation from Minas Gerais state. [ABSTRACT FROM AUTHOR]

Little is known about the immune response of lizards to Leishmania parasties. In this study, we conducted the first liver transcriptome analysis of two lizards (Phrynocephalus przewalskii and Eremias multiocellata) challenged with L. donovani , endemic to the steppe desert region of northwestern China. Our results revealed that multiple biological processes and immune-related signaling pathways are closely associated with the immune response to experimental L. donovani infection in the two lizards, and that both lizards show similar changes to mammals in terms of immunity to Leishmania. However, the interspecific divergence of the two lizards leads to different transcriptomic changes. In particular, in contrast to P. przewalskii , the challenged E. mutltiocellata was characterized by the induction of down-regulation of most DEGs. These findings will contribute to the scarce resources on lizard immunity and provide a reference for further research on immune mechanisms in reptiles. [Display omitted] • First report of liver transcriptome analysis in two lizards infected with Leishmania donovani. • Leishmania challenge induces many immune related genes in both lizards. • Interspecific divergence in lizards leads to distinct transcriptomic changes. • Lizards show similar changes to mammals in terms of immunity to Leishmania. [ABSTRACT FROM AUTHOR]

To understand the spread of parasite and the persistence of infection in an ecological environment, it is essential to investigate their transmission possibilities. Vertical transmission of pathogens from mother to offspring is a fundamental opportunity, notwithstanding a relatively under-researched topic, especially in wildlife animals. We studied whether there is vertical transmission of a haemogregarinid blood parasite of Iberian green lizard (Lacerta schreiberi). To study infection of mothers, embryos and freshly hatched juveniles, their blood smears and molecular analyses of their tail tissue were used. Examining blood smears, seventy-one percent of females were found to be infected, but molecular analyses of all mothers showed positive results for the blood parasite. Based on molecular data the parasite was identified as a Karyolysus species. In contrast, no parasite was found in the blood smears of the freshly hatched juveniles, and we could not detect Karyolysus in the embryos or tail tissue of offspring using molecular methods either. Based on our results, vertical transmission of Karyolysus blood parasites is unlikely in the Iberian green lizard. [Display omitted] • Molecular analyses showed a Karyolysus species infects Lacerta schreiberi. • All females-mothers but none of their embryos and offspring were infected. • Vertical transmission of Karyolysus genus is unlikely in the Iberian green lizard. [ABSTRACT FROM AUTHOR]

To assess the success rate, onset, duration and extent of motor/sensory block following neuraxial injection of two dosages of bupivacaine in bearded dragons (Pogona vitticeps). Prospective, randomized, blinded, crossover experimental study. A total of 10 adult bearded dragons (0.3 ± 0.1 kg). After sedation with alfaxalone (15 mg kg–1 subcutaneously), neuraxial injections were performed with 1 or 2 mg kg–1 bupivacaine hydrochloride (0.5%, treatments BUP-1 and BUP-2, respectively) in a randomized treatment sequence with a 7 day washout period. If the initial bupivacaine injection was not successful within 10 minutes, a second injection was performed at the same dose. Mechanical stimulation of limbs, 25%, 50%, 75% of the trunk's length and cloacal tone were assessed. Success rate following the first neuraxial injection was 95%, which increased to 100% after the second injection. Motor/sensory block were noted by 5 minutes after the injection of bupivacaine at either dose. BUP-2 was associated with more cranial spread. The median (range) duration of cloacal tone loss was longer following treatment BUP-2 [120 (75–225) minutes] than followed treatment BUP-1 [83 (25–135) minutes; p = 0.03]. Duration of pelvic limb motor block was comparable between both doses, lasting a median of 68 minutes in both treatments (p = 0.94). There was a transient, not clinically relevant increase from baseline in heart rate in treatment BUP-1 only. No significant difference from baseline in respiratory rate was noted in either treatment; however, two animals in treatment BUP-2 became apneic (10–20 minutes). Bupivacaine (1 mg kg–1) is recommended for neuraxial anesthesia in bearded dragons. In treatment BUP-2, extensive cranial spread resulted in apnea and motor block of the thoracic limb in several animals; therefore this dose is not recommended. [ABSTRACT FROM AUTHOR]

Due to often insufficient information, reptiles suffer welfare issues and increased mortality in captivity. In particular, the impact of the social environment remains poorly understood, despite evidence suggesting its' importance for welfare in a wide range of social animals. The current study investigated how pair housing changes enclosure use, basking and hiding behaviour in tokay geckos (Gekko gecko). While the captive conditions and husbandry procedures employed in this study align with existing literature recommendations, they have not been previously evaluated for their suitability for this particular species. The results show that, when socially deprived, lizards were more likely to move and hide before feeding. Furthermore, males were more likely to be found at the front than females during pair housing but not during single housing. Finally, contrary to single housing, enclosure temperature had no effect on the probability to move and hide behind a shelter during pair housing. Consistently, lizards were more likely to bask after feeding across housing conditions, and females were more likely to bask before their first clutch. Together, pair housing decreases movement and hiding in relation to human presence (feeding), which might indicate that pair housing improves tokay gecko welfare and suggest that the presence of a conspecific should be considered to improve welfare policies in social reptiles. This study serves as a baseline for future research into how enclosure furnishings, husbandry techniques, and enrichment practices impact the welfare of tokay geckos which will be crucial for refining our understanding of and improving on the welfare of reptiles in captivity. • Reptiles suffer welfare issues and increased mortality in captivity. • I investigated how pair housing changes behaviour in tokay geckos (Gekko gecko). • When socially deprived, lizards were more likely to move and hide before feeding. • Males were more likely to be at the front than females during pair housing. • These results indicate that pair housing improves tokay gecko welfare. [ABSTRACT FROM AUTHOR]

Malarial protozoa commonly infect both wild and captive lizards but the effects on the general health of these animals are not fully understood. We describe four clinical cases of Plasmodium infection in captive black and white tegus (Salvator merianae). The animals presented with lethargy, anorexia, dehydration and stomatitis. Plasmodium infection was identified in blood smears from all animals. Treatment with a sulphamethoxazole-trimethoprim combination resolved the infection and clinical improvement was observed within 21 days. This is the first report of successful treatment of clinical plasmodiid infection in captive tegus. [ABSTRACT FROM AUTHOR]

Despite periodontal disease being recognized as a common condition in captive bearded dragons, there is a lack of data regarding the prevalence. A soft diet has previously been cited as the main risk factor linked to the disease, although there has been little research conducted into the etiology since the disease was first described. The aims of this study were to investigate the prevalence of dental abnormalities and disease in captive Central bearded dragons in the United Kingdom, and to begin to investigate the risk factors affecting the presence and increased severity of disease in this species. Data collection was conducted from 20 veterinary practices across the United Kingdom from March to October 2018. All bearded dragons presented to participating practices during this time period were assessed for the presence of dental disease, and for each animal a standardized data collection form was completed to provide information concerning the animal's signalment, diet, and health status. Severity of any dental disease was also graded in a subset of bearded dragons (n = 147) by two of the authors using a grading system from 0 to 5. The prevalence of dental abnormalities and disease was 50% in the sampled population of 304 bearded dragons. Increasing age, an abnormal body condition score, presence of concurrent disease, as well as presence of fruit in the diet were all significant risk factors for the presence of dental abnormalities and disease. Contrary to previous reports, neither presence of different live foods in the diet, nor presence of vegetable matter in the diet had any significant associations with dental abnormalities and disease, challenging some of the assumptions made to date about the etiology of dental disease in Central bearded dragons. This study instead found that fruit could be the main dietary risk factor for dental disease and should be excluded from the captive diet of these animals. This study has found a strong association between increasing age and presence of dental abnormalities and disease, and stresses the importance of a thorough oral exam, especially in older individuals. [ABSTRACT FROM AUTHOR]

Background : Alternatives to gross external anatomical sex determination are often required, peculiarly in species displaying poor or absent gross sexual dimorphism, such as the beaded lizard. This study evaluates results of hemipenile contrast radiography accuracy as compared to ultrasonography of the same beaded lizard (Heloderma alvarezi and Heloderma horridum). Methods : Eleven captive adult beaded lizards (4 H. alvarezi and 7 H. horridum), underwent hemipenis contrast radiography, and results compared with coelomic ultrasound. Results : By ultrasound, 2 lizards were females and 9 were males. By contrast hemipenis radiography, 2 animals were females and 9 were males. In this sample, there was a Kappa concordance of 1. Conclusions and clinical relevance : In this species, contrast hemipenis radiography proved to be a reliable diagnostic tool for hemipenes identification, and sex determination with all test specimens. Further studies including a larger number of animals and different lizard species are warranted. [ABSTRACT FROM AUTHOR]

Lizards of the Helodermatidae (Anguimorpha) family consist of at least two well recognized species: Heloderma horridum horridum and Heloderma suspectum suspectum. They contain specialized glands in their jaws that produce venomous secretions that causes envenoming symptoms to bitten animals. One way to study proteins from such secretions is by RNA-seq; a powerful molecular tool to characterize the transcriptome of such specialized gland, and its protein secretions. The total RNA from venom gland tissues of H. horridum horridum was extracted and a cDNA library was constructed and sequenced. Overall, 114,172 transcripts were found, and 199 were annotated based on sequence similarities to previously described peptides/proteins. Transcripts coding for putative exendins, defensins, natriuretics and serine protease inhibitors were the most highly expressed. Transcripts that code for several putative serine proteases, phospholipases, metalloproteases, lipases, L-amino oxidase and nucleases were also found. Some of the novel identified transcripts were translationally controlled tumor proteins, venom factors, vespryns, waprins, lectins, cystatins and serine protease inhibitors. All these new protein structures may contribute to a better understanding of the venomous secretions of the Helodermatidae family. Image 1 • In the transcriptome of Heloderma horridum horridu m identified one hundred ninety-nine annotated transcripts. • Thirty-two protein families were found in Hh. horridum venom gland with diverse putative functions. • Enzymes were the most abundant components of venom gland transcriptomic. • The annotated protein-coding transcripts have identities to snake (42%) and lizard (36%) venom components. • Transcripts coding putative exendins, defensins, natriuretics, and kazal inhibitor were the most highly expressed. [ABSTRACT FROM AUTHOR]

Climate change is creating novel thermal environments via rising temperatures and increased frequency of severe weather events. Short-term phenotypic adjustments, i.e., phenotypic plasticity, may facilitate species persistence during adverse environmental conditions. A plastic response that increases thermal tolerance is heat hardening, which buffers organisms from extreme heat and may enhance short term survival. However, heat hardening responses may incur a cost with concomitant decreases in thermal preference and physiological performance. Thus, phenotypic shifts accompanying a hardening response may be maladaptive in warming climates. Understanding how heat hardening influences other traits associated with fitness and survival will clarify its potential as an adaptive response to altered thermal niches. Here, we studied the effects of heat hardening on boldness behavior in the color polymorphic tree lizard, Urosaurus ornatus. Boldness in lizards influences traits such as territory maintenance, mating success, and survivorship and is repeatable in U. ornatus. We found that when lizards underwent a heat hardening response, boldness expression significantly increased. This trend was driven by males. Bolder individuals also exhibited lower field active body temperatures. This behavioral response to heat hardening may increase resource holding potential and territoriality in stressful environments but may also increase predation risk. This study highlights the need to detail associated phenotypic shifts with stress responses to fully understand their adaptive potential in rapidly changing environments. • Heat tolerance plasticity (heat hardening) influences behavior in Urosaurus ornatus. • Boldness behavior in lizards increases with a heat hardening response. • Response driven by boldness increases in males. [ABSTRACT FROM AUTHOR]

Lizard regeneration derives from the re-activation of a number of developmental genes after tail amputation. Among genes with the highest expression, as indicated from the transcriptome, is lix1 which functional role is not known. An antibody that cross-reacts with the lizard Podarcis muralis lix1 has been utilized to detect by immunofluorescence the sites of localization of the protein in the regenerating tail. Lix1-protein is almost exclusively localized in the regenerating spinal cord (ependyma) and nerves growing into the blastema, in sparse blastema cells but is undetectable in other tissues. Since the spinal cord is essential to stimulate tail regeneration it is hypothesized that the lix1 protein is part of the signaling or growing factors produced from the regenerating spinal cord that are needed for tail regeneration of the lizard tail. [ABSTRACT FROM AUTHOR]

Until a few decades ago, play was considered a behavior unique to birds and mammals. Although play in other vertebrates is still a neglected research subject, data on it has been slowly accumulating, and are reviewed here. Now we know that animals as diverse as stingrays, cichlid fishes, monitor lizards, softshell turtles, and crocodiles can be unexpectedly playful. This knowledge has implications to broader theoretical problems, but much more research attention is needed to utilize its potential. [ABSTRACT FROM AUTHOR]

A variety of phenotypic traits in reptiles are affected by conditions during embryonic development, a phenomenon known as developmental plasticity. In particular, many traits in which expression changes with temperature, such as locomotor performance or growth rates, are also developmentally plastic. However, much less is known about the extent to which traits associated with thermal ecology, such as thermal tolerance and behavioral thermoregulation, are developmentally plastic. Here, we review the literature on developmental plasticity in physiological and behavioral traits associated with thermal ecology in reptiles. Most studies on developmental plasticity of thermal traits have assessed plasticity in behavioral traits, such as selected temperature or time spent basking, and these studies have found mixed support for the presence of developmental plasticity in behavioral thermal traits. In contrast, very few studies have assessed developmental plasticity in physiological traits, yet these studies generally support a developmentally plastic basis for thermal tolerance. Most studies have only tested for developmental plasticity in thermal ecology traits at the hatchling stage, which limits our understanding of the benefits of developmental plasticity to individuals, or the adaptive significance of developmental plasticity in populations. We recommend that research on developmental plasticity in reptile thermal ecology be expanded to include incubation conditions other than mean temperature, consider traits associated with cold-tolerance, and endeavor to understand how developmental plasticity in thermal ecology traits is beneficial. In particular, determining how long differences persist over ontogeny, and testing for benefits of developmental plasticity across multiple life stages, are crucial first steps towards understanding the adaptive significance of developmental plasticity in thermal ecology traits. • Phenotypic plasticity can match an individual's phenotype to its environment. • Developmental plasticity in thermal ecology traits is poorly understood in reptiles. • Developmental plasticity is more common in physiological than behavioral traits. • Some developmentally plastic differences persist beyond the neonate stage. • Research is needed on the adaptive significance of developmental plasticity. [ABSTRACT FROM AUTHOR]

• We investigated the effects of developmental temperature on juvenile Pogona vitticeps incubated at two different temperatures • Cool-incubated lizards grew more quickly, but hot-incubated lizards completed a foraging task more often and were faster • Results suggest a potential trade-off between growth and foraging speed, which could influence an animal's life history After laying their eggs, oviparous reptiles are reliant on the external environment to provide the required incubation conditions for successful embryonic development. Egg incubation temperature can impact the behaviour of various species of reptiles, but previous experiments have focused on the impact of incubation environment on hatchlings, with only a limited number of studies focussing on the longer-term behavioural consequences of incubation environment. This study investigated the effects of developmental environment on bearded dragon lizards (Pogona vitticeps) that were incubated at different temperatures within the natural range; half of them were incubated at a 'hot' temperature (30 ± 3 °C) and half at a 'cold' temperature (27 ± 3 °C). The growth and foraging behaviour of the lizards was then compared over 18 weeks of development. Although the lizards incubated at a cool temperatures grew more quickly, those incubated at the hotter temperature completed the foraging task more often and had significantly faster running speeds. These results show that egg incubation temperature impacts the foraging behaviour of juvenile lizards and suggest a potential trade-off between growth and foraging speed, which could influence an animal's life history trajectory. [ABSTRACT FROM AUTHOR]

• Moderate costs induced an investment trade-off between thermoregulation and T b , and individual variation decreased with the increase of costs. • Lower average T p values were observed in the trials where costs were high as a result of lower volunteer T b 's. Upper volunteer T b did not varied. • Individual variation resulted in two main thermoregulatory patterns defined as "Relaxed thermoregulator" and "Precise thermoregulator". • Individual variation within the population may enable species to cope with habitat alterations and as well as toadjust to new environments. Studies on ectothermic vertebrates generally lead to average indicators of thermal preferences measured in the laboratory, which do not say about responses to natural environmental change and may not inform about individual variation and its triggering mechanisms. We studied whether and how changes in costs of thermoregulation influence the preferred temperature (T p) of individual lizards and their energetic investment in thermoregulation by exposing specimens to three treatments of increasing costs, recording body temperature (T b) and distance walked (energetic investment). Moderate costs induced an investment trade-off between energy-investment in thermoregulation and T b , and highlighted individual variation that decreased with higher costs. Lower average T p 's were observed in the high costs trials as a result of the decreased values of the lower and upper voluntary T b 's. As costs increased, lizards walked a shorter overall distance and accepted lower T b 's, but lizards still engaged in costly thermoregulation. Individual variation resulted in two main thermoregulatory patterns that in certain ecological contexts may have an important role in decision-making and adjusting to temperatures that are far from optimal temperatures for performance and physiological processes. [ABSTRACT FROM AUTHOR]

To evaluate if intramuscular (IM) lidocaine potentiates the sedative effects of alfaxalone and results in cardiopulmonary changes in sedated bearded dragons. Prospective experimental crossover study. A group of eight adult bearded dragons (Pogona vitticeps) weighing 334 ± 46 g. Animals were administered alfaxalone (10 mg kg−1 subcutaneously) and 15 minutes later either lidocaine 2% (4 mg kg−1) or 0.9% sodium chloride (0.2 mL kg−1) was administered IM in the thoracic limb. The treatments were randomized and separated by 7 days. Sedation was scored based on body position, eye closure, jaw tone, swallowing, pick up response, righting reflex and pelvic limb withdrawal reflex. Heart rate (HR) and respiratory rate (f R) were recorded every 5 minutes until recovery from sedation. Lidocaine had no significant effect on duration or depth of alfaxalone sedation. HR increased significantly for <10 minutes following lidocaine administration by a median (interquartile range) of 33% (28–37%; p = 0.024). No clinically significant effects on f R occurred following lidocaine injection. Administration of lidocaine 2% (4 mg kg−1) IM did not potentiate alfaxalone sedation but resulted in a transient clinically relevant increase in HR. [ABSTRACT FROM AUTHOR]

A 4-year-old, intact female, inland bearded dragon (Pogona vitticeps) presented with a 12- to 24-hour history of severe lethargy, anorexia, and obtundation. Hematology and serum biochemistry revealed a marked monocytosis and toxic left shift, and severe hyperphosphatemia with normocalcemia. Radiographs revealed a fluid-filled, distended coelom, and suspected pericardial effusion or cardiomegaly. An ultrasound-guided coelomocentesis was performed. Direct smears revealed histiocytic to heterophilic inflammation with intracellular and free proteinaceous globular material (yolk globules), and intrahistiocytic bacterial rods, consistent with a bacterial coelomitis. The patient died despite treatment. On necropsy, free fluid and fibrin in the coelom along with yellow, lamellated material, enlarged ovarian follicles with serosal fibrinous plaques, and pericardial effusion were detected. A subacute to chronic necrotizing and granulomatous to heterophilic myocarditis, oophoritis, and hepatitis were present on microscopic examination. Additionally, large numbers of Listeria monocytogenes were isolated on aerobic bacterial culture of affected ovarian tissue. Collectively, the results culminated in a diagnosis of septic Listeria monocytogenes infection. Listeriosis has rarely been reported in reptiles and has not been reported in reptiles in the North America. Information on treatment for listeriosis in other species and zoonotic concerns has been reviewed to provide assistance for management of future cases of reptilian listeriosis. [ABSTRACT FROM AUTHOR]

Abstract Objective To assess the feasibility, success rate, onset, duration and extent of motor/sensory block following intrathecal injection of lidocaine in bearded dragons (Pogona vitticeps). Study design Prospective experimental study. Animals A group of eight adult bearded dragons (0.333 ± 0.048 kg). Methods The animals were sedated with alfaxalone (15 mg kg−1) subcutaneously. Neuraxial injections were performed with 1% lidocaine (2 mg kg−1) or 0.9% sodium chloride (0.2 mL kg−1) in all animals with a 7 day interval. If the initial injection did not result in motor block of the pelvic limbs within 10 minutes, a second injection was performed at the same dose. Measurements consisted of bilateral mechanical stimulation of limbs; 25%, 50%, and 75% of the trunk's length; and cloacal tone. Animals were monitored for any untoward side effects by monitoring heart rate (HR), respiratory rate, righting reflex and head position. Results Success rate following the first injection of lidocaine was 50% (four out of eight animals) and increased to 75% (six out of eight animals) following a second injection. Onset of motor/sensory block occurred within 5 minutes in all successful injections. Duration and extent were variable, with most bearded dragons presenting motor/sensory block of cloaca and pelvic limbs (six out of six) and 25% of the trunk (five out of six) with mean ± standard deviation (range) duration of 49 ± 28 (25–100), 48 ± 25 (25–90) and 40 ± 14 (25–50) minutes, respectively. Confirmation of intrathecal injection by aspiration of cerebrospinal fluid was not possible. Neuraxial lidocaine significantly increased depth and duration of sedation, with a transient increase in HR, compared with saline. Conclusion and clinical relevance Neuraxial lidocaine is a feasible technique with moderate success rate and low risk of complication in bearded dragons. This technique has potential for improving the management of anesthesia in this species. [ABSTRACT FROM AUTHOR]

Highlights • Serine protease inhibitors, serpins, are highly expressed in lizard regenerating blastema. • Western blot and immunohistochemistry shows the localization of serpins in the regenerating tail. • Serpin immunolocalization is mainly seen in the regenerating epidermis and ependyma. • Serpins may contribute to the formation of an epidermal and ependymal barrier to microbes. • The permanence of these barriers favors tail regeneration. Abstract Tail regeneration in lizard is stimulated from the apical epidermis and spinal cord, the principal sources of growth factors and signaling proteins that sustain regeneration. Immunolabeling shows that serpins (serine protease inhibitors), which genes are among those most up-regulated during tail regeneration, are prevalently immunolocalized in the regenerating epidermis and ependyma. Western blot detects main protein bands extracted from regenerating tail at 25-27 and 48-52 kDa. The former band may correspond to p27 serpin, a degraded immunogenic fragment of serpin detected in psoriasis and cancer. This suggests that also in lizard the degradation of these proteins occurs but is uncertain whether it is physiological with some function or the fragments derive from the extractive process. In the regenerating epidermis serpins are mainly accumulated in pre-corneous and corneous layers (alpha-layers), and also in the forming oberhautchen and hard beta-layer. In the tail tip serpin-immunolabeling is mainly seen in the ependymal tube and with lower intensity in blastema (mesenchymal) cells. Aside the control on endogenous proteases for the formation of a protective corneous barrier, serpins may also form a protective anti-microbial barrier for the ependyma. The protection of the epidermis and ependyma allows these tissue to continue the stimulation for tail regeneration. [ABSTRACT FROM AUTHOR]

Abstract Iguana iguana is a lizard found in South America, and its metabolism is directly related to ambient heat. However, the physiology underlying the effect of temperature change on the metabolism of these reptiles has not been fully elucidated. I. iguana hemoglobin (iHb) was isolated and purified by exclusion chromatography. Mass spectrometry, circular dichroism, SAXS and spectroscopic characterization were used to evaluate the primary and secondary structures and oligomeric state of iHb. The secondary structure of intact iHb, which mainly consisted of α-helices, was not stable if heated at 60 °C. Autoxidation rates of iHb were measured at 30 and 40 °C, revealing a suggestive bi-exponential behavior. Furthermore, by lowering the pH from 7.4 to 6.0, an increase in autoxidation rate was observed, indicating a behavior responsive to metabolic changes. Compared to ATP, ADP showed an allosteric effect on iHb oxygenation by lowering its oxygen binding. Alignment of the amino acid sequences revealed that iHb exhibits conserved substitution of a residue at the allosteric site, suggesting that some unknown molecular mechanism accounts for the allosteric effect caused by ADP. The ability of iHB to oxygenate is directly related to metabolic changes, ensuring the survival of Iguana iguana in different environments. [ABSTRACT FROM AUTHOR]

The Anti-mullerian hormone (AMH), also known as Mullerian inhibiting substance (MIS), is a glycoprotein that belongs to transforming growth factor β superfamily. The significance of AMH during gonadal differentiation is not clearly deciphered in reptiles. Hence, current study aims to know the onset of AMH secretion and its functional role in Mullerian duct regression gonadal differentiation in tropical lizard, Calotes versicolor which exhibits a novel Female-Male-Female-Male (FMFM) pattern of temperature-dependent sex determination (TSD). The Immunohistochemistry and qRT-PCR techniques were employed to analyze the gonadal expression profile of AMH during different stages of embryonic development. The eggs of the lizard were incubated at both male-producing temperature (MPT: 25.5 ± 0.5 °C) and female-producing temperatures (FPT: 31.5 ± 0.5 °C). The results reveal that the onset of AMH gene expression was observed as early as oviposition prior to the immunolocalization of AMH protein at early-TSP (Temperature-sensitive period). The substantial rise in the intensity of the immunoreaction of AMH protein in the cytoplasm confining to Sertoli cells of seminiferous cords at MPT with low level of expression at FPT during gonadal sex differentiation, specify sexually dimorphic expression of AMH protein. Further, with the onset of sexual differentiation, the developing testis immensely expresses AMH gene which is 7-fold greater than that of transcripts levels in female embryos; signifies its conserved role in Mullerian duct regression thereby promoting testis differentiation. The robust immunnoexpression of AMH protein during post-gonadal differentiation coincides with the onset of the regression of Mullerian duct point out a positive correlation between testis differentiation and Mullerian duct regression, thus facilitating testis differentiation pathway. Based on the immunoexpression pattern of AMH protein and transcript levels of AMH gene, it is inferred that AMH plays a significant role in Mullerian duct regression, favoring testis differentiation. • The qRT-PCR analysis reveals onset of AMH gene expression as early as at oviposition. • Expression of AMH gene and its protein suggests sexually dimorphic pattern. • Robust expression of AMH coincides with the onset of Mullerian duct regression. • AMH expression shows + ve correlation amid testis differentiation & MD regression. • AMH plays significant role in favoring testis differentiation in C. versicolor. [ABSTRACT FROM AUTHOR]

accumulating evidence indicates that during tail regeneration in lizards the initial stage of regenerative blastema is a tumor-like proliferative outgrowth that rapidly elongates into a new tail composed of fully differentiated tissues. Both oncogenes and tumor-suppressors are expressed during regeneration, and it has been hypothesized that an efficient control of cell proliferation avoids that the blastema is turned into a tumor outgrowth. in order to determine whether functional tumor-suppressors are present in the growing blastema we have utilized protein extracts collected from early regenerating tails of 3–5 mm that have been tested for a potential anti-tumor effect on in-vitro culture by using cancer cell lines from human mammary gland (MDA-MB-231) and prostate cancer (DU145). at specific dilutions, the extract determines a reduction of viability in cancer cells after 2–4 days of culture, as supported by statistical and morphological analyses. While control cells appear viable, treated cells result damaged and produce an intense cytoplasmic granulation and degeneration. this negative effect on cell viability and proliferation is absent using tissues from the original tail supporting the hypothesis that only regenerating tissues synthesize tumor-suppressor molecules. The study suggests that the regenerating tail of lizard at the stages here selected contains some molecules that determine inhibition of cell viability on the cancer cells analyzed. [ABSTRACT FROM AUTHOR]

Temperature is one of the main environmental variables shaping the evolution and biology of terrestrial ectotherms. The Pantanal is the largest continuous wetland in the World. However, a lack of knowlegde still exists on the thermal ecology of terrestrial ectothems from this wetland. In this context, the thermal ecology of the lizard Tropidurus lagunablanca Carvalho, 2016 (Squamata, Tropiduridae) was investigated in the Brazilian Pantanal. The thermal ecology and microhabitat use of lizards from a riparian forest was compared to lizards from a park savanna. At both studied areas, air and body temperatures of lizards did not differ between sexes. Mean T. lagunablanca body temperatures were higher at the savanna compared to the forest, while air temperatures were similar in both habitats. The main substrates were tree trunks, with a frequency of approximately 90% of the observations. Lizards from the savanna used higher perches than those from the forest despite -in average- trees were higher at the forest. Lizard sun and shade exposure was similar for both areas. Lizards from both habitats showed similar strong linear relationships between body and air temperatures. However, lizard behaviour of using tree trunk perches differently under different sunlight situations suggests that these lizards actively thermoregulate. Further research on the thermoregulation abilities of this species, with a null hypotesis and behavioral observations will shed light on lizard thermal biology. Studies on the ecophysiological aspects of these lizards should be a priority to understand how they will react to climate change and which conservation measures will be more effective concerning their preservation. [ABSTRACT FROM AUTHOR]

Regeneration of secondary forests on previously deforested or degraded land is one of the most dominant forms of land-use change in the tropics. However, the response of animal communities to forest regeneration is poorly understood. To evaluate support for thermal quality as a mechanism driving reptile species distributions during secondary forest succession, we measured operative temperatures and occupancy in three successional forest stages (pasture, secondary forest, and old growth forest) for two anole species common in the landscape ( Norops humilis and Norops limifrons ). We then measured thermal preference in laboratory experiments and used operative temperature and temperature preference measurements to determine how thermal quality of habitat changes over the course of secondary forest succession, and if occupancy varies as a function of thermal quality. We found that thermal quality was lowest in pasture habitat because of a large frequency of temperatures above the thermal preference range. However, in low thermal quality pasture sites, riparian habitats and remnant trees provided a thermal refuge for both lizard species. Our results support thermal quality as a mechanism for reptile species distributions in altered landscapes and highlight the importance of the maintenance of riparian corridors. [ABSTRACT FROM AUTHOR]

SOAE from the last major lizard family not yet systematically investigated, the teiids, were collected from the genera Callopistes , Tupinambis and Cnemidophorus . Although their papillae show characteristics of the family Teiidae, the papillae differ both in their size and in the arrangement of uni- and bi-directional hair-cell areas. Among these three genera, Callopistes showed few (2 or 3) SOAE peaks, whereas the other two genera showed more (up to 6 per ear). In the absence of knowledge of the tonotopic maps, however, it was not possible to clearly relate the spectral patterns to the differences in papillar anatomy, suggesting that the determinants of these patterns may be more subtle than anticipated. [ABSTRACT FROM AUTHOR]

Epimorphic regeneration is a process allowing the animal to regain its lost structure which depends on the resident pluripotent stem cells as well as de-differentiation of existing cells to form multi-potent stem cells. Many studies have been done to understand the appendage regeneration mechanism. The animal model used since decades is an urodele amphibian the axolotl. However, this ability is also seen in some members of reptiles, mainly lizards which on autotomy of tail regain the same by forming a replica of its lost tail. Lizards being closer to mammals are of greater interest and cannot be neglected. Hence, a stage specific protein profiling was undertaken in order to find the peptides playing a major role in epimorphosis. 2-DGE being basic tool for creating a protein profile was used. With advent of newer modern technology, label-free analysis which uses MS/MS was also performed. The study reports the peptides involved in apoptosis, inflammation and ECM remodelling across the stages of lizard tail regeneration for the first time. Apart from these peptides, structural protein, enzymes involved in metabolism have also been highlighted in the current study to give a bigger picture of the processes and the specific peptides required for tail regeneration. [ABSTRACT FROM AUTHOR]

Growing-season burns are increasingly used in upland hardwood forest for multiple forest management goals. Many species of reptiles and amphibians are ground-dwelling, potentially increasing their vulnerability to prescribed fire, especially during the growing-season when they are most active. We used drift fences with pitfall traps to experimentally assess how herpetofaunal species and communities responded to early, growing-season burns, dormant-season burns, and unburned controls. We documented no adverse effects of either growing-season burns or dormant-season burns on any common herpetofaunal taxa, but capture rates of total, adult, and juvenile five-lined skinks ( Plestiodon fasciatus ) were greater following growing-season burns. Most measurements reflected little or transient change in forest structure. However, canopy cover decreased by an average of 16% in growing-season burns within four growing-seasons of burning, with some tree mortality in patches where fire temperature likely was hotter. Our study suggests that even modest reductions in canopy cover may positively affect relative abundance and reproductive success of P. fasciatus . We cautiously suggest that a higher mean ground-level fire temperature and the physiologically active condition of vegetation in growing-season burns interacted to damage a greater proportion of trees, resulting in more canopy thinning than in dormant-season burns. However, weather, fuel types and condition, vegetation structure, and topography interact to affect fire intensity and the level of mortality or damage to canopy trees within and among stands, regardless of season conducted. We suggest that herpetofaunal response, for the species we studied, is more closely linked to change in canopy cover than to season of burn per se . [ABSTRACT FROM AUTHOR]

Herein we review our work involving dispersed adrenocortical cells from several lizard species: the Eastern Fence Lizard (Sceloporus undulatus), Yarrow's Spiny Lizard (Sceloporus jarrovii), Striped Plateau Lizard (Sceloporus virgatus) and the Yucatán Banded Gecko (Coleonyx elegans). Early work demonstrated changes in steroidogenic function of adrenocortical cells derived from adult S. undulatus associated with seasonal interactions with sex. However, new information suggests that both sexes operate within the same steroidogenic budget over season. The observed sex effect was further explored in orchiectomized and ovariectomized lizards, some supported with exogenous testosterone. Overall, a suppressive effect of testosterone was evident, especially in cells from C. elegans. Life stage added to this complex picture of adrenal steroidogenic function. This was evident when sexually mature and immature Sceloporus lizards were subjected to a nutritional stressor, cricket restriction/deprivation. There were divergent patterns of corticosterone, aldosterone, and progesterone responses and associated sensitivities of each to corticotropin (ACTH). Finally, we provide strong evidence that there are multiple, labile subpopulations of adrenocortical cells. We conclude that the rapid (days) remodeling of adrenocortical steroidogenic function through fluctuating cell subpopulations drives the circulating corticosteroid profile of Sceloporus lizard species. Interestingly, progesterone and aldosterone may be more important with corticosterone serving as essential supportive background. In the wild, the flux in adrenocortical cell subpopulations may be adversely susceptible to climate-change related disruptions in food sources and to xenobiotic/endocrine-disrupting chemicals. We urge further studies using native lizard species as bioindicators of local pollutants and as models to examine the broader eco-exposome. [Display omitted] • Lizard adrenocortical cells have sex-related steroidogenic profiles over seasons. • Male and female cells operate within the same steroidogenic budget over seasons. • Testosterone is a suppressor of lizard adrenocortical steroidogenic function. • Lizard adrenocortical cells exist as functionally distinct, labile subpopulations. • The subpopulation composition drives the profile of corticosteroid secretion. [ABSTRACT FROM AUTHOR]

High altitude environments provide a fertile ground for investigating the benefits of phenotypic adjustments at several levels of biological organization. Low oxygen partial pressure and low environmental temperature are the main limiting factors that promote phenotypic variation in different organs, such as the lung and heart. Although high-altitude environments act like natural laboratories, most morphological studies conducted to date lack replication. Here, we evaluated organ mass variation in nine populations of Sceloporus grammicus , throughout three altitudinal gradients (mountains) from the Trans-Mexican volcanic belt. A total of 84 individuals from three different altitudes at three different mountains were collected. Then, we used generalized linear models to analyze the pattern of variation in internal organs mass as a function of altitude and temperature. We observed a striking pattern of altitudinal variation in the size of cardiorespiratory organs: while heart mass increased with altitude and decreased with temperature, the lung showed a significant statistical interaction between mountain transect and temperature. Overall, our results support the hypothesis that cardiorespiratory organs should be bigger in populations occurring at higher altitudes. Moreover, the study of different mountain systems allowed us to observe some differences in one mountain in relation to the other two. [Display omitted] • This is the first study analyzing changes in organ mass due to altitude and temperature across replicated elevational gradients for an ectothermic vertebrate. • Heart mass increases with altitude and decreases with temperature, and lung mass shows a significant interaction among mountain and environmental variables. • Our results mostly agree with previous studies analyzing the effect of altitude on cardiorespiratory organs mass, but also suggest that lizards could respond in a different way in distinct mountain systems. [ABSTRACT FROM AUTHOR]

Fibroblast Growth Factors 1-2 (FGF1-2) stimulate tail regeneration in lizards and therefore the distribution of their receptors, FGFR1-2, in the regenerating tail of the lizard. Podarcis muralis has been studied using immunofluorescence and western blotting. Immunoreactive protein bands at 15–16 kDa for FGF1-2 in addition to those at 50–65 kDa are detected in the regenerating epidermis, but weak bands at 35, 45 and 50 kDa appear from the regenerating connective tissues. Strongly immunolabeled bands for FGFR1 at 32, 60, and 80 kDa and less intense for FGFR2 only appear in the regenerating tail. In normal tail epidermis and dermis, higher MW forms are present at 80 and 115–140 kDa, respectively, but they disappear in the regenerating epidermis and dermis where low MW forms of FGFR1-2 are found at 50–70 kDa. Immunolocalization confirms that most FGFR1-2 are present in the wound epidermis, Apical Epidermal Peg, ependymal tube while immunolabeling lowers in regenerating muscles, blastema cells, cartilage and connectives tissues. The likely release of FGFs from the Apical Epidermal Peg and ependyma and the presence of their receptors in these tissues may determine the autocrine stimulation of proliferation and a paracrine stimulation of the blastema cells through their FGF Receptors. [ABSTRACT FROM AUTHOR]

Inorganic materials, such as steel, were functionalized by ultrashort laser pulse irradiation (fs- to ps-range) to modify the surface’s wetting behavior. The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. A systematic experimental study of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, spikes, etc.). Analyses of the surface using optical as well as scanning electron microscopy revealed morphologies providing the optimum similarity to the natural skin of lizards. For mimicking skin structures of moisture-harvesting lizards towards an optimization of the surface wetting behavior, additionally a two-step laser processing strategy was established for realizing hierarchical microstructures. In this approach, micrometer-scaled capillaries (step 1) were superimposed by a laser-generated regular array of small dimples (step 2). Optical focus variation imaging measurements finally disclosed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting properties. [ABSTRACT FROM AUTHOR]

The regulation of body temperature is a critical function for animals. Although reliant on ambient temperature as a heat source, reptiles, and especially lizards, make use of multiple voluntary and involuntary behaviors to thermoregulate, including postural changes in body orientation, either toward or away from solar sources of heat. This thermal orientation may also result from a thermoregulatory drive to maintain precise control over cranial temperatures or a rostrally-driven sensory bias. The purpose of this work was to examine thermal orientation behavior in adult and neonatal bearded dragons ( Pogona vitticeps ), to ascertain its prevalence across different life stages within a laboratory situation and its interaction with behavioral thermoregulation. Both adult and neonatal bearded dragons were placed in a thermal gradient and allowed to voluntarily select temperatures for up to 8 h to observe the presence and development of a thermoregulatory orientation preference. Both adult and neonatal dragons displayed a non-random orientation, preferring to face toward a heat source while achieving mean thermal preferences of ~ 33–34 °C. Specifically, adult dragons were more likely to face a heat source when at cooler ambient temperatures and less likely at warmer temperatures, suggesting that orientation behavior counter-balances local selected temperatures but contributes to their thermoregulatory response. Neonates were also more likely to select cooler temperatures when facing a heat source, but required more experience before this orientation behavior emerged. Combined, these results demonstrate the importance of orientation to behavioral thermoregulation in multiple life stages of bearded dragons. [ABSTRACT FROM AUTHOR]

Owner practices affect pet welfare, and little is known about the ways in which reptile owners attempt to meet their pet's welfare needs. We asked 316 pet lizard owners in Victoria, Australia, for information on the ways in which they seek to meet their pet's environmental, dietary, behavioral, social, and health needs. Items were generated based on the Victorian Code of Practice (CoP) for the Private Keeping of Reptiles and in collaboration with the then President of the Victorian Herpetological Society. Results suggest that many owners are not fully complying with the CoP. Moreover, even those who are compliant may not be meeting their animal's full repertoire of needs. Nearly half of the owners do not have an enclosure large enough to meet the standards set in the CoP, and a similar percentage do not seasonally vary the environmental conditions provided in their lizard's enclosure. It is likely, therefore, that many lizards experience captivity-related stress because of inadequate enclosures. Many owners underestimate the likely total cost of their pet lizard over the course of its lifetime, suggesting that educational campaigns highlighting the financial and time costs of lizard ownership are merited. Future behavioral research should aim to better understand pet lizard needs to optimize welfare outcomes for these animals. [ABSTRACT FROM AUTHOR]

Summary The MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) gene encodes a noncoding RNA that is processed into a long nuclear retained transcript ( MALAT1 ) and a small cytoplasmic tRNA-like transcript ( mascRNA ). Using an RNA sequence- and structure-based covariance model, we identified more than 130 genomic loci in vertebrate genomes containing the MALAT1 3′ end triple-helix structure and its immediate downstream tRNA-like structure, including 44 in the green lizard Anolis carolinensis . Structural and computational analyses revealed a co-occurrence of components of the 3′ end module. MALAT1-like genes in Anolis carolinensis are highly expressed in adult testis, thus we named them testis-abundant long noncoding RNAs (tancRNAs). MALAT1 -like loci also produce multiple small RNA species, including PIWI-interacting RNAs (piRNAs), from the antisense strand. The 3′ ends of tancRNAs serve as potential targets for the PIWI-piRNA complex. Thus, we have identified an evolutionarily conserved class of long noncoding RNAs (lncRNAs) with similar structural constraints, post-transcriptional processing, and subcellular localization and a distinct function in spermatocytes. [ABSTRACT FROM AUTHOR]

Tail autotomy is a crucial antipredatory lizard response, which greatly increases individual survival, but at the same time also compromises locomotor performance, sacrifices energy stores and induces a higher burden due to the ensuing response of regenerating the lost body part. The potential costs of tail autotomy include shifts in energy allocation and metabolic rates, especially in juveniles, which invest their energy primarily in somatic growth. We compared the metabolic rates and followed the growth of juvenile males with and without regenerating tails in the Madagascar ground gecko ( Paroedura picta ), a nocturnal ground-dwelling lizard. Geckos with intact tails and those that were regrowing them grew in snout-vent-length at similar rates for 22 weeks after autotomy. Tail regeneration had a negligible influence on body mass-corrected metabolic rate measured at regular intervals throughout the regenerative process. We conclude that fast-growing juveniles under the conditions of unrestricted food can largely compensate for costs of tail loss and regeneration in their somatic growth without a significant impact on the total individual body mass-corrected metabolic rate. [ABSTRACT FROM AUTHOR]

Lizard tail regeneration depends from growth of the apical tip and autonomous regeneration of a new spinal cord, cartilaginous tube and muscles. The presence of embryonic signaling pathways is likely involved and we have focused on immunolocalization of Wnt1 protein in regenerating tissues, a protein promoting proliferation and tumorigenesis. Western blot indicates some immunoreactive bands in the expected range at 46 and 33 kDa in the regenerating tail. Immunolocalization indicates that Wnt1 is prevalently detected in the apical wound epidermis, blastema, and ependyma ampulla of the regenerating tail while it lowers in other tissues of more proximal regions close to the original tail stump. Although a gradient for Wnt1 was not detected, the higher immunofluorescence present in the apical region of the blastema and around the regenerating spinal cord indicates that the protein could be secreted from the apical wound epidermis and the ependyma and might influence cell proliferation in the blastema, the distal-most growing center of the new tail. The present observations suggest the involvement of the Wnt pathway to direct the process of tail regeneration in lizard. The stimulation of proliferation of epidermal and mesenchymal cells in the apical blastema by Wnt proteins remains to be experimentally validated. [ABSTRACT FROM AUTHOR]

Pregnancy is a challenging period for egg laying squamates. Carrying eggs can encumber females and decrease their locomotor performance, potentially increasing their risk of predation. Pregnant females can potentially reduce this handicap by selecting higher temperatures to increase their sprint speed and ability to escape from predators, or to speed up embryonic development and reduce the period during which they are burdened with eggs (‘selfish mother’ hypothesis). Alternatively, females might select more stable body temperatures during pregnancy to enhance offspring fitness (‘maternal manipulation hypothesis’), even if the maintenance of such temperatures compromises a female's locomotor performance. We investigated whether pregnancy affects the preferred body temperatures and locomotor performance of female velvet geckos Amalosia lesueurii . We measured running speed of females during late pregnancy, and one week after they laid eggs at four temperatures (20°, 25°, 30° and 35 °C). Preferred body temperatures of females were measured in a cost-free thermal gradient during late pregnancy and one week after egg-laying. Females selected higher and more stable set-point temperatures when they were pregnant (mean =29.0 °C, T set =27.8–30.5 °C) than when they were non-pregnant (mean =26.2 °C, T set =23.7–28.7 °C). Pregnancy was also associated with impaired performance; females sprinted more slowly at all four test temperatures when burdened with eggs. Although females selected higher body temperatures during late pregnancy, this increase in temperature did not compensate for their impaired running performance. Hence, our results suggest that females select higher temperatures during pregnancy to speed up embryogenesis and reduce the period during which they have reduced performance. This strategy may decrease a female's probability of encountering predatory snakes that use the same microhabitats for thermoregulation. Selection of stable temperatures by pregnant females may also benefit embryos, but manipulative experiments are necessary to test this hypothesis. [ABSTRACT FROM AUTHOR]

The transformation of natural habitats into urban landscapes dramatically alters thermal environments, which in turn, can impact local biota. Ectothermic organisms that are oviparous are particularly sensitive to these altered environments because their embryos cannot behaviorally thermoregulate and the surrounding environment determines the temperature experienced during development. We studied the effects of urban and forested thermal environments on embryo development and hatchling phenotypes in two non-native lizards ( Anolis sagrei and A. cristatellus ) in metropolitan Miami, Florida. To determine if embryos from urban and forested sites are adapted to their respective thermal environments, we incubated eggs from each site using temperatures that simulate likely nest conditions in both urban and forested environments. For both species, urban thermal environments accelerated embryonic development, but had no impact on egg survival or any of the phenotypic traits that were measured (e.g., body size, running performance, and locomotor behavior). Our results provide no evidence that embryos from urban and forested sites are adapted to their respective thermal environments. Instead, the lack of any major effects suggest that embryos of both species are physiologically robust with respect to novel environments, which could have facilitated their success in establishing in non-native ranges and in human-modified landscapes. [ABSTRACT FROM AUTHOR]

Flufenoxuron is a widely used pesticide to inhibit the synthesis of chitin during insect development and its effect on the growth of lizards has been little addressed. The hypothalamus-pituitary-thyroid (HPT) axis plays an important role on the development of lizards. In this study, the lizards at different development stages (proliferation and resting stages) were exposed to flufenoxuron for 21 days. The plasma thyroid hormone levels, thyroid gland histopathology and expression profiles of thyroid hormone receptors ( trα , trβ ), deiodinases ( dio1 , dio2 ), and transthyretin ( ttr ) genes were measured to evaluated the toxic effect of flufenoxuron on the HPT axis at different stages. The flufenoxuron exposure showed more seriously effect on the triiodothyronine (T3) level at resting phase than that at proliferation stage. The follicle epithelium cell height in the thyroid was only significantly increased when the exposed male lizards were at proliferation stage. The alteration of HPT axis-related genes expression was gender and tissue dependent after flufenoxuron treatment. The lizards exposed to flufenoxuron showed that the trα , trβ , dio1 , dio2 , and ttr genes in the female liver were more sensitive at the proliferation stage than that at the resting stage. In the male brain, the expressions of trα , trβ , dio1 , and dio2 gene were significant decreased at proliferation stage while significant increased at resting stage after flufenoxuron exposure. Therefore, the thyroid endocrine system of lizards could be affected by the flufenoxuron exposure and the different development stage should also be considered when study the toxic effect of contaminants on the lizards. [ABSTRACT FROM AUTHOR]

Yabeinosaurus was the first lizard genus described from the Early Cretaceous Jehol Biota of China. The holotype of the type species, Y. tenuis , is an immature skeleton but it has been lost for decades. A second species, Y. youngi, was erected based on another immature skeleton and is distinguished by its longer, more gracile limbs. In 2001, a juvenile skeleton from the Jingangshan locality of Liaoning was designated as the neotype for Y. tenuis . Subsequently, several further specimens from other localities, juvenile and adult, have been attributed to this species. Here we describe a second lizard specimen from the neotype locality. In anterior tooth shape, finger-like mandibular angular process, cranial sculpture, maxilla shape, and short, robust humerus, the new specimen resembles adult and subadult material currently attributed to Y. tenuis, but it differs in having bicuspid posterior teeth and a straight rather than a hooked angular process of the mandible. We propose a new species ( Y. bicuspidens sp. nov.) for this specimen which represents the first occurrence of bicuspid teeth in an Early Cretaceous lizard from China. However, the recognition of a second species at the neotype locality raises a taxonomic problem. Due to the immaturity of the designated holotype and neotype of Y. tenuis , they cannot be coded for the jaw and dental characters that distinguish the two robust-limbed species. This renders Yabeinosaurus tenuis a nomen dubium. Here we propose that Yabeinosaurus tenuis should be treated as a historic taxon, permitting retention of the generic name under ICZN rules, and erect a second new species ( Y. robustus sp. nov.) for the principal robust-limbed morphotype in the Jehol Biota with monocuspid posterior teeth and a hooked angular process. [ABSTRACT FROM AUTHOR]

The spiny lizard Sceloporus minor exhibits substantial variation in a variety of life history traits, but the factors promoting this variation remain unclear. We analyzed within- and between-population variation in morphological traits in two populations (El Enzuelado and La Manzana, Hidalgo, Central Mexico), and estimated the genetic distance between populations on the basis of sequence variation of the mitochondrial genes encoding a fragment of the ND4 gene, all of tRNA-His and tRNA-Ser, and a fragment of tRNA-Leu. Consistent with earlier reports, males and females exhibited marked sexual dimorphism in body size and coloration. The genetic distance between the two populations was 0.024, slightly greater than the distance measured within each population (0.015 for La Manzana and 0.003 for El Enzuelado). Maximum likelihood analysis indicated that these populations were indeed conspecific, along with other studied populations of S. minor . The morphological differences and the previously described variation in reproductive traits contrast with the limited genetic variation between populations reported herein. This suggests that a combination of both phenotypic plasticity and genes of large effect may be contributing to variation in anatomical and physiological traits in Sceloporus minor . [ABSTRACT FROM AUTHOR]

Of the 934 lizard species evaluated by the International Union for the Conservation of Nature (IUCN), at least one-third is threatened with extinction. However, there are no reports of semen cryopreservation efforts for lizards. Invasive Argentine black and white tegus were captured in the Florida Everglades, and sperm was collected postmortem. Initial motility score (IMS; % motile × speed of progression 2 × 100), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded. Sperm was diluted in TEST-yolk buffer with a final glycerol or dimethylsulfoxide (DMSO)concentration of 8%, 12%, or 16%, and frozen at 0.3 °C, 1.0 °C, or 6.3 °C/min. At thaw, all variables were expressed as the percentage of initial (%IMS, %IPL, and %IAC). The 0.3 °C freeze rate was more successful than 1.0 °C and 6.3 °C/min in preserving %IMS and %IPL. DMSO preserved %IMS, %IPL, and %IAC better than glycerol. To determine the best overall cryopreservation protocol, a sperm quality index was calculated, giving equal weight to each of the three indicators of cryosurvival. Because there were significant interactions between freeze rate and cryoprotectant concentration, each treatment was compared with all others. The sperm quality index analysis revealed that tegu sperm frozen at 0.3 °C/min with 12% DMSO exhibited the highest postthaw viability compared with all other treatments. [ABSTRACT FROM AUTHOR]

The well-preserved trackway of a lacertiform, lizard-like trackmaker from the Haman Formation (Cretaceous) of Korea is described as Neosauroides koreaensis ichnogen. et ichnosp. nov. This is the only example of a Cretaceous lacertiform or lizard-like trackway currently known in the global track record. Although lacertiform trackways, mostly assigned to the ichnogenus Rhynchosauroides , are common in the global Triassic, they are almost entirely absent in the Jurassic and Cretaceous. Moreover, ichnological classification criteria allow that Neosauroides is morphologically distinct from Rhynchosauroides at the genus level, and more like the tracks of the extant lizard Sceloporus . The reasons for the conspicuous lack of post-Triassic occurrences are not certain, but not due to a post-Triassic lack of potential lizard trackmakers. Thus, the preservation biases are likely due to paleobiological factors such as trackmaker ecology and paleoenvironmental preference. [ABSTRACT FROM AUTHOR]

We studied the thermal physiology of the Andean lizard Stenocercus guentheri in order to evaluate the possible effects of global warming on this species. We determined the preferred body temperature ( T pref ), critical thermals (CTmin, CTmax), and hours of restriction and activity. T pref was 32.14±1.83 °C; CTmin was 8.31 °C in adults and 9.14 °C in juveniles, whereas CTmax was 43.28 °C in adults and 41.68 °C in juveniles. To assess extinction risk, we used the model created by Sinervo et al. (2010) and predicted that 16.7% of populations will have a high risk of extinction by 2020, with an increase to 26.7% by 2050. These results suggest that this species, despite being able to maintain its T pref through behavioral thermoregulation and habitat selection, could be physiologically sensitive to climate warming; thus, the potential for local adaptation may be limited under a warmer climate. Further studies focusing on the ability of S. guentheri to evolve higher T pref and thermal tolerances are needed to understand the ability of this species to respond to climate change. [ABSTRACT FROM AUTHOR]