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Tail anomalies, such as bifurcation and trifurcation, are observed in different species of Lacertid lizards. In the present study, bilateral tail bifurcation was observed in male specimens belonging to Darevskia clarkorum and Darevskia rudis in the Eastern Black Sea Region of Turkey. In the specimen of D. clarkorum, SVL and TL are 55.37 mm and 66.43 mm, respectively. Bifurcation from the base of the tail occurred at 42.82 mm. The regenerated tail is 8.45 mm. SVL and TL are 83.56 mm and 128.93 mm, respectively in the specimen of D. rudis. Bifurcation from the base of the tail occurred at 33.38 mm. The length of the regenerated tail is 46.77 mm. [ABSTRACT FROM AUTHOR]

We provide the first description of the skull, osteoderms, and hyoid apparatus of the poorly known alligator lizard Elgaria panamintina, and compare the cranial osteology of that species to the widespread and well-studied taxon Elgaria multicarinata. Patterns of morphological variation resulting from ontogenetic transformations and pathology are discussed. We employed x-ray computed tomography (CT) scans to examine two adult specimens of Elgaria panamintina and two adult specimens of Elgaria multicarinata, in addition to examining multiple traditionally prepared skeletal specimens of the latter species. CT scans provide simultaneous study of both articulated and disarticulated elements, allowing us to describe and document the morphology of the skull with exceptional precision and detail. The description of the skull of Elgaria panamintina serves as a generalization for all Elgaria; here we provide the first complete description of the skull of this genus for future uses in morphological and phylogenetic studies of both extant species and fossils. [ABSTRACT FROM AUTHOR]

The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with negative impact on individuals could generate high costs and affect the expression of these sexual signals. In this sense, parasites are a main cost for their hosts. To probe the effect of parasites on the structural-based coloration of a lacertid species Lacerta schreiberi, we have experimentally removed ticks from a group of male Iberian green lizards using an acaricide treatment (i.e., the broad-use insecticide fipronil). All individuals were radio-tracked and recaptured after 15 days to study changes in coloration in both the ultraviolet (UV)-blue (structural-based) and UV-yellow (structural and pigment-based) ornamentations after manipulation, as well as changes in endo- and ectoparasitic load and body condition. Additionally, after the experiment, we measured the skin inflammatory response to a mitogen. The fipronil treatment was effective in reducing ticks and it was associated with a significant reduction of hemoparasite load. Throughout the season, individuals treated with fipronil tended to maintain the brightness of the UV-blue throat coloration while control lizards tended to increase it. However, individuals treated with fipronil that were not infected with hemoparasites significantly reduced the brightness of the UV-blue throat coloration. Individuals with a higher initial tick load exhibited a lower UV saturation increment (UV-blue) and a higher brightness increment (UV-yellow) during the experiment. Overall these results experimentally support the idea that parasites adversely influence the expression of the structural-based coloration of male Iberian green lizards. This adds evidence to the hypothesis that sexual ornaments in lizards function as honest signals. [ABSTRACT FROM AUTHOR]

Understanding the joint evolutionary and ecological underpinnings of sympatry among close relatives remains a key challenge in biology. This problem can be addressed through joint phylogenomic and phenotypic analysis of complexes of closely related lineages within, and across, species and hence representing the speciation continuum. For a complex of tropical geckos from northern Australia- Gehyra nana and close relatives-we combine mtDNA phylogeography, exon-capture sequencing, and morphological data to resolve independently evolving lineages and infer their divergence history and patterns of morphological evolution. Gehyra nana is found to include nine divergent lineages and is paraphyletic with four other species from the Kimberley region of north-west Australia. Across these 13 taxa, 12 of which are restricted to rocky habitats, several lineages overlap geographically, including on the diverse Kimberley islands. Morphological evolution is dominated by body size shifts, and both body size and shape have evolved gradually across the group. However, larger body size shifts are observed among overlapping taxa than among closely related parapatric lineages of G. nana, and sympatric lineages are more divergent than expected at random. Whether elevated body size differences among sympatric lineages are due to ecological sorting or character displacement remains to be determined. [ABSTRACT FROM AUTHOR]

Populations adapting independently to the same environment provide important insights into the repeatability of evolution at different levels of biological organization. In the 20th century, common wall lizards ( Podarcis muralis) from southern and western Europe were introduced to England, north of their native range. Nonnative populations of both lineages have adapted to the shorter season and lower egg incubation temperature by increasing the absolute rate of embryonic development. Here, we tested if this adaptation is accompanied by signatures of directional selection in the transcriptomes of early embryos and, if so, if nonnative populations show adaptive convergence. Embryos from nonnative populations exhibited gene expression profiles consistent with directional selection following introduction, but different genes were affected in the two lineages. Despite this, the functional enrichment of genes that changed their expression following introduction showed substantial similarity between lineages, and was consistent with mechanisms that should promote developmental rate. Moreover, the divergence between nonnative and native populations was enriched for genes that were temperature-responsive in native populations. These results indicate that small populations are able to adapt to new climatic regimes, but the means by which they do so may largely be determined by founder effects and other sources of genetic drift. [ABSTRACT FROM AUTHOR]

Background: The development of male- or female-specific phenotypes in squamates is typically controlled by either temperature-dependent sex determination (TSD) or chromosome-based genetic sex determination (GSD). However, while sex determination is a major switch in individual phenotypic development, it is unknownhow evolutionary tran- sitions between GSD and TSD might impact on the evolution of squamate phenotypes, particularly the fast-evolving and diverse genitalia. Here, we take the unique opportunity of studying the impact of both sex determination mecha- nisms on the embryological development of the central bearded dragon ( Pogona vitticeps ). This is possible because of the transitional sex determination system of this species, in which genetically male individuals reverse sex at high incubation temperatures. This can trigger the evolutionary transition of GSD to TSD in a single generation, making P. vitticeps an ideal model organism for comparing the effects of both sex determination processes in the same species. Results: We conducted four incubation experiments on 265 P. vitticeps eggs, covering two temperature regimes (“normal" at 28 °C and “sex reversing" at 36 °C) and the two maternal sexual genotypes (concordant ZW females or sex-reversed ZZ females). From this, we provide the first detailed staging system for the species, with a focus on genital and limb development. This was augmented by a new sex chromosome identification methodology for P. vit- ticeps that is non-destructive to the embryo. We found a strong correlation between embryo age and embryo stage. Aside from faster growth in 36 °C treatments, body and external genital development was entirely unperturbed by temperature, sex reversal or maternal sexual genotype. Unexpectedly, all females developed hemipenes (the genital phenotype of adult male P. vitticeps ), which regress close to hatching. Conclusions: The tight correlation between embryo age and embryo stage allows the precise targeting of specific developmental periods in the emerging field of molecular research on P. vitticeps . The stability of genital development in all treatments suggests that the two sex-determining mechanisms have little impact on genital evolution, despite their known role in triggering genital development. Hemipenis retention in developing female P. vitticeps , together with frequent occurrences of hemipenis-like structures during development in other squamate species, raises the possibility of a bias towards hemipenis formation in the ancestral developmental programme for squamate genitalia. [ABSTRACT FROM AUTHOR]

Femoral glands of male lizards produce waxy secretions that are involved in inter- and intraspecific chemical communication. The main components of these secretions are proteins and lipids, the latter having been extensively studied and already associated to male quality. On the opposite, the composition and role of proteins are nearly unknown, the only available information coming from few studies on iguanids. These studies got the conclusion that proteins might have a communicative function, notably they could signal individual identity. A generalization of these findings requires the extension of protein analysis to other lizard families, and the primary detection of some patterns of individual variability. Using the common wall lizard Podareis muralis as a model species, the protein fraction of the femoral pore secretions was investigated to provide the first characterization of this component in a lacertid lizard and to explore its source of variability, as a first step to support the hypothesized communicative role. Samples of proteins from femoral secretions were collected from 6 Italian populations and subjected to 1-dimensional electrophoresis. The binary vector of the band presence/absence was used to define the individual profiles. Protein fraction is found to have a structured pattern, with both an individual and a population component. Although the former supports the potential communicative role of proteins, the latter offers a double interpretation, phylogenetic or environmental, even though the phylogenetic effect seems more likely given the climatic resemblance of the considered sites. Further studies are necessary to shed light on both these issues. [ABSTRACT FROM AUTHOR]

Amputated tails of lizards regenerate while limbs form scars which histological structure is very different from the original organs. Lizards provide useful information for regenerative medicine and some hypotheses on the loss of regeneration in terrestrial vertebrates. Analysis of tail and limb transcriptomes shows strong downregulation in the tail blastema for immunoglobulins and surface B and T receptors, cell function, and metabolism. In contrast, in the limb blastema genes for myogenesis, muscle and cell function, and extracellular matrix deposition but not immunity are variably downregulated. The upregulated genes show that the regenerating tail is an embryonic organ driven by the Wnt pathway and non-coding RNAs. The strong inflammation following amputation, the non-activation of the Wnt pathway, and the upregulation of inflammatory genes with no downregulation of immune genes indicate that the amputated limb does not activate an embryonic program. Intense inflammation in limbs influences in particular the activity of genes coding for muscle proteins, cell functions, and stimulates the deposition of dense extracellular matrix proteins resulting in scarring limb outgrowths devoid of muscles. The present study complements that on upregulated genes, and indicates that the regenerating tail requires immune suppression to maintain this embryonic organ connected to the rest of the tail without be rejected or turned into a scar. It is hypothesized that the evolution of the adaptive immune system determined scarring instead of organ regeneration in terrestrial vertebrates and that lizards evolved the process of tail regeneration through a mechanism of immuno-evasion. [ABSTRACT FROM AUTHOR]

Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall, diet appears a relatively poor predictor of interspecific differences in the broad chemical profiles of secretions of lacertid lizards. [ABSTRACT FROM AUTHOR]

Soil contamination caused by the widespread use of pesticides is one of the main environmental problems facing conservation organizations. ( S )-metolachlor (SM) is a selective pre-emergent herbicide that poses potential risks to soil-related organisms such as reptiles. The present study elucidated the toxic effects of SM (3 and 30 mg/kg soil weight) in Eremias argus . The results showed that growth pattern was similar between the sexes in breeding season. For males, both kidney coefficient (KC) and testis coefficient in the exposure group were significantly different from those in the control group, while only KC in the high-dose group was significantly higher for females. Based on histopathological analysis, the livers of female lizards were more vulnerable than those of males in the exposure group. A reduction in total egg output was observed in SM exposed lizards. Accumulation studies indicated that skin exposure may be an important route for SM uptake in E. argus , and that the liver and lung have strong detoxification abilities. In addition, the body burdens of the lizards increased with increasing SM concentration in the soil. [ABSTRACT FROM AUTHOR]

In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. [ABSTRACT FROM AUTHOR]

The genus Darevskia comprises over 20 species of small-bodied lizards, mainly occurring in the Caucasus Mountain Region. They show differences in body size, scalation and coloration, however, fully diagnostic characters that could separate the species with a high confidence level are still lacking. The early phylogenetic hypothesis of this group was based on ‘traditional’ analysis of morphology, based on multiple body and head measurements and scalation traits. Later, a molecular phylogeny of the genus rejected some of the proposed topology based on morphological traits. In this paper, we used quantitative morphological data (outline-based shape data) to test phylogenetic similarities, as proposed by these earlier hypotheses. We analyzed the pileus shape and the anal area of more than 200 individuals, representing six species of Darevskia, using outline based elliptic Fourier analysis. The analysis did confirm a clustering of the individuals and species (using UPGMA) from the same mitochondrial DNA clade. Hence, the phylogenetic affinity of the major clades in Darevskia could be identified using both molecular methods and outline analysis, whereas a traditional quantitative morphological analysis could not. [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]

The evolution of sexual dimorphismis predicted to occur through reductions in between-sex genetic correlations (rmf) for shared traits, but the physiological and genetic mechanisms that facilitate these reductions remain largely speculative. Here, we use a paternal half-sibling breeding design in captive brown anole lizards (Anolis sagrei) to show that the development of sexual size dimorphismis mirrored by the ontogenetic breakdown of rmf for body size and growth rate. Using transcriptome data from the liver (which integrates growth and metabolism), we show that sex-biased gene expression also increases dramatically between ontogenetic stages bracketing this breakdown of rmf. Ontogenetic increases in sex-biased expression are particularly evident for genes involved in growth, metabolism, and cell proliferation, suggesting that they contribute to both the development of sexual dimorphism and the breakdown of rmf. Mechanistically, we show that treatment of females with testosterone stimulates the expression of male-biased genes while inhibiting the expression of femalebiased genes, thereby inducing male-like phenotypes at both organismal and transcriptomic levels. Collectively, our results suggest that sex-specific modifiers such as testosterone can orchestrate sex-biased gene expression to facilitate the phenotypic development of sexual dimorphism while simultaneously reducing genetic correlations that would otherwise constrain the independent evolution of the sexes. [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]

1. Tail autotomy is mainly considered an antipredator mechanism. Theory suggests that predation pressure relaxes on islands, subsequently reducing autotomy rates. 2. Intraspecific aggression, which may also cause tail loss, probably intensifies on islands due to the higher abundance. 3. We studied whether tail autotomy is mostly affected by predation pressure or by intraspecific competition. We further studied whether predator abundance or predator richness is more important in this context. 4. To test our predictions, we examined multiple populations of two gecko species: Kotschy's gecko (Mediodactylus kotschyi; mainland and 41 islands) and the Mediterranean house gecko (Hemidactylus turcicus; mainland and 17 islands), and estimated their abundance together with five indices of predation. 5. In both species, autotomy rates are higher on islands and decline with most predation indices, in contrast with common wisdom, and increase with gecko abundance. In M. kotschyi, tail-loss rates are higher on predator and viper-free islands, but increase with viper abundance. 6. We suggest that autotomy is not simply, or maybe even mainly, an antipredatory mechanism. Rather, such defence mechanisms are a response to complex direct and indirect biotic interactions and perhaps, in the case of tail autotomy in insular populations, chiefly to intraspecific aggression. [ABSTRACT FROM AUTHOR]

The epidermis of lizards is made of multiple alpha- and beta-layers with different characteristics comprising alpha-keratins and corneous beta-proteins (formerly beta-keratins). Three main modifications of body scales are present in the lizard Anolis carolinensis: gular scales, adhesive pad lamellae, and claws. The 40 corneous beta-proteins present in this specie comprise glycine-rich and glycine-cysteine-rich subfamilies, while the 41 alpha-keratins comprise cysteine-poor and cysteine-rich subfamilies, the latter showing homology to hair keratins. Other genes for corneous proteins are present in the epidermal differentiation complex, the locus where corneous protein genes are located. The review summarizes the main sites of immunolocalization of beta-proteins in different scales and their derivatives producing a unique map of body distribution for these structural proteins. Small glycine-rich beta-proteins participate in the formation of the mechanically resistant beta-layer of most scales. Small glycine-cysteine beta-proteins have a more varied localization in different scales and are also present in the pliable alpha-layer. In claws, cysteine-rich alpha-keratins prevail over cysteine-poor alpha-keratins and mix to glycine-cysteine-rich beta-proteins. The larger beta-proteins with a molecular mass similar to that of alpha-keratins participate in the formation of the fibrous meshwork present in differentiating beta-cells and likely interact with alpha-keratins. The diverse localization of alpha-keratins, beta-proteins, and other proteins of the epidermal differentiation complex gives rise to variably pliable, elastic, or hard corneous layers in different body scales. The corneous layers formed in the softer or harder scales, in the elastic pad lamellae, or in the resistant claws possess peculiar properties depending on the ratio of specific corneous proteins. [ABSTRACT FROM AUTHOR]

We investigated age structure, body size and longevity in two breeding populations of Darevskia clarkorum inhabiting altitudes ranging from 450 m a.s.l. (Kamilet) to 2250 m a.s.l. (Ba,syayla) in Turkey by skeletochronology performed on the phalanges. The mean age was found to be 6 years in the Kamilet population and 7 years in the Ba,syayla population. The maximum life span was 10 years in the lowland population while it was 12 years in the highland population. Age at sexual maturity of both males and females was 1-2 years in the lowland population while it was 2-3 for both sexes in the highland population. Both age and SVL of specimens from the Kamilet population were significantly different between the sexes while age and SVL did not differ significantly between the sexes in Ba,syayla population. As a conclusion, we observed that the mean age, longevity and age at maturity were increased by altitude while there was a decrease based on the mean SVL in the highland population of D. clarkorum. Our data on body size, longevity and age at sexual maturity may contribute to conservation efforts for this endangered species. [ABSTRACT FROM AUTHOR]

During tail regeneration in lizards, the epidermis forms new scales comprising a hard beta-layer and a softer alpha-layer. Regenerated scales derive from a controlled folding process of the wound epidermis that gives rise to epidermal pegs where keratinocytes do not invade the dermis. Basal keratinocytes of pegs give rise to suprabasal cells that initially differentiate into a corneous wound epidermis and later in corneous layers of the regenerated scales. The immunodetection of a putative p53/63 protein in the regenerating tail of lizards shows that immunoreactivity is present in the nuclei of basal cells of the epidermis but becomes mainly cytoplasmic in suprabasal and in differentiating keratinocytes. Sparse labelled cells are present in the regenerating blastema, muscles, cartilage, ependyma and nerves of the growing tail. Ultrastructural observations on basal and suprabasal keratinocytes show that the labelling is mainly present in the euchromatin and nucleolus while labelling is more diffuse in the cytoplasm. These observations indicate that the nuclear protein in basal keratinocytes might control their proliferation avoiding an uncontrolled spreading into other tissues of the regenerating tail but that in suprabasal keratinocytes the protein moves from the nucleus to the cytoplasm, a process that might be associated to keratinocyte differentiation. [ABSTRACT FROM AUTHOR]

Many ectotherms adjust their metabolic rate seasonally in association with variations in environmental temperatures. The range and direction of these seasonal changes in reptilian metabolic rates are thought to be linked to the seasonality of activity and energy requirements. The present study was conducted to measure the standard metabolic rate (SMR) of seasonally-acclimatized Uromastyx philbyi with different body masses at 20, 25, 30, 35 and 40 °C using open-flow respirometry during the four seasons. SMR was mass-dependent. The mean exponent of mass, “ b ”, in the metabolism-body mass relation was 0.76 (variance=0.0007). Likewise, SMR increased as temperature increased with low Q 10 values at high temperatures and high Q 10 values at low temperatures. The lowest and highest Q 10 values were achieved for temperature ranges of 30–35 °C for summer-acclimatized dhabbs (Q 10 =1.6) and 20–25 °C for winter-acclimatized dhabbs (Q 10 =3.9). Seasonal acclimatization effects were obvious at all temperatures (20–40 °C). Winter-acclimatized dhabbs had the lowest metabolic rates at all temperatures. The seasonal acclimatization patterns displayed by U. philbyi may represent a valuable adaptation for herbivorous desert lizards that inhabit subtropical deserts to facilitate activity during their active seasons and to conserve energy during inactivity at low temperatures. [ABSTRACT FROM AUTHOR]

Tail autotomy is a widespread antipredator strategy among lizards, which consists of the capability of willingly detaching a portion of the tail in order to escape predator attacks. Nonetheless, tail autotomy has a number of costs, including reduced sprint speed which increases predation risk. However, lizards regenerate the tail following autotomy, although a regenerated tail is usually shorter and histologically different from the original tail. In the present work, we assess the effect of tail regeneration on sprint speed by comparing Psammodromus algirus lizards with intact and regenerated tails under controlled laboratory conditions. We found that sprint speed was similar in lizards with intact and regenerated tails. Therefore, tail regeneration following autotomy effectively restored sprint speed, although regenerated tails were shorter than intact ones. Thus, regenerating shorter tails could diminish anabolic costs with no negative consequences on flight ability. [ABSTRACT FROM AUTHOR]

Effective digestion is decisive for survival. In nature, where most animals feed sporadically, high digestive performance guarantees they will gain the most out of their infrequent meals. Larger body size implies higher energy requirements and digestion should function properly to provide this extra energy. Comparing Skyros wall lizards (Podarcis gaigeae) from Skyros Island to large ("giant") lizards from a nearby islet, we tested the hypothesis that digestion in large individuals is more efficient than in small individuals. We anticipated that giant lizards would have higher gut passage time (GPT), longer gastrointestinal (GI) tracts and higher apparent digestive efficiencies (ADE) for lipids, sugars and proteins. These predictions were only partially verified. Giant lizards indeed had longer (than expected based on body length) GI tract and longer GPTs but achieved higher ADE only for proteins, while ADEs for lipids and sugars did not differ from the normal-sized lizards. We postulated that the observed deviations from the typical digestive pattern are explained by cannibalism being more prominent on the islet. Giant lizards regularly consume tail fragments of their conspecifics and even entire juveniles. To break down their hard-to-digest vertebrate prey, they need to extend GPT and thus they have developed a longer GI tract. Also, to fuel tail regeneration they have to raise ADEproteins. It seems that larger size, through the evolution of longer GI tract, enables giant lizards to take advantage of tails lost in agonistic encounters as a valuable food source. [ABSTRACT FROM AUTHOR]

Over the coming decades, our planet will experience a dramatic increase in average temperatures and an increase in the variance around those temperatures leading to more frequent and harsher heat waves. These changes will impact most species and impose strong selection on physiological traits., Rapid acclimation is the most direct way for organisms to respond to such extreme events, but we currently have little understanding of how the capacity to mount such plastic responses evolves. Accordingly, there is some urgency to determine how the physiological response to high temperatures varies within species, and how this variation is driven by the environment., Here, we investigate heat-hardening capacity - a rapid physiological response that confers a survival advantage under extreme thermal stress - across 13 populations of a rain forest lizard, Lampropholis coggeri, from the tropics of north-eastern Australia., Our results reveal that heat hardening is constrained in these lizards by a hard upper thermal limit for locomotor function (approximately 43 °C). Further, hardening response shows strong geographic variation associated with thermal environment: lizards from more predictable and more seasonal thermal environments exhibited greater hardening compared with those from more stochastic and less seasonal habitats. This finding - that predictability in thermal variation influences hardening capacity - aligns closely with theoretical expectations., Our results suggest that tropical species may harbour adaptive variation in physiological plasticity that they can draw from in response to climate change, and this variation is spatially structured in locally adapted populations. Our results also suggest that, by using climatic data, we can predict which populations contain particular adaptive variants; information critical to assisted gene flow strategies. [ABSTRACT FROM AUTHOR]

Geckos with subdigital adhesive pads can scale smooth vertical surfaces in defiance of gravity. The deployment of the adhesive system is activated by the musculoskeletal system during active traverses of such surfaces, but adhesion on such substrata can also be achieved by passive means, with the body weight of the gecko applying tensile loading to the adhesive setae, maintaining prolonged, static contact with the surface. To investigate whether passively induced adhesion is employed by geckos holding station on smooth vertical surfaces, we investigated the magnitude of shear force generation for the manus and pes, and the positioning of the limb segments and digits in Chondrodactylus bibronii in freely selected resting postures (head-up, head-down and facing laterally to the left and right). Our results indicate that different subsets of digits occupy positions consistent with them being passively loaded in different body orientations. Limb segment and digit orientation are consistent within, and differ between, the resting postures, and relatively few of the 20 digits are positioned to take advantage of gravitationally induced loading in any posture. The pedal digits have greater adhesive potential than the manual ones and, more frequently, capitalize on passive loading than do manual digits. This is especially evident in the commonly adopted head-down resting posture. [ABSTRACT FROM AUTHOR]

Although Ablepharus kilaibelii and its subspecies are wide-spread, being distributed from the Carpathian Basin through the Balkans to Iraq, their habitat and environmental niche is poorly known. Ablepharus kilaibeliifitzingeri is almost entirely limited to the Carpathian Basin, and is amongst the most strictly protected and least known reptiles of Central and Eastern Europe. The main aim of our study was to determine habitat use preferences of different age groups of A. kitaibelii fitzingeri and Lacerta viridis. The occurrence of green lizard was determined by the abundance of refugia rather than by the naturalness of grasslands. The snake-eyed skink prefers semi-natural grasslands with abundant tussock-forming grass or sedge species, avoiding densely shrubby places. For the first time, we show that woodland mosaics lacking shrubs and temporary grasslands next to forest edges are important for the species. Microhabitat use by snake-eyed skink varies with age group; adults preferring shady edge zones rich in leaf litter and shadier grassland spots provided by woodland mosaics, whereas juveniles were found in natural, more open grasslands far from forest edges and in woodland mosaics with dense shrubby understory. Our results contribute to a better understanding of the ecological needs of A. kitaibelii fitzingeri. Our methodology could be adapted to other species and subspecies of Ablepharus. Based on our results, it is important to reconsider habitat management activities, which should not be limited to shrub control: the main goal should be the development of a diverse habitat structure. [ABSTRACT FROM AUTHOR]

The present study evaluated the influence of age, sex and habitat on the frequency of tail loss in three species of endemic lizards to Mexico. The treated taxa are Sceloporus bicanthalis, S. subpictus and mesaspis gadovii and are sympatric in the mountains of the Central Valley of Oaxaca. The differences in the frequency of tail loss were evaluated by sex, age, habitat and species by Chi square test on a sample size of 259 organisms collected between April 2010 and March 2011. The results indicate that habitat structure, sex or age of individuals (except in Mgadovii) did not influence significantly in the frequency of mutilation of the tail in the three species analyzed. However, significant differences between species occur, these differences may be the result of agonistic behavior of each species, and of a pressure of predation different for each taxon. [ABSTRACT FROM AUTHOR]

The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial. [ABSTRACT FROM AUTHOR]

Two new species of scale-mites parasitizing lizards of the family Agamidae (Sauria) are described: Pterygosoma blandfordi n. sp. from Psammophilus blanfordanus (Stoliczka) (Agamidae: Draconinae) from South India and Pterygosoma balochistani n. sp. from Laudakia nupta nupta (De Filippi) (Agamidae: Agaminae) from Pakistan. Pterygosoma blandfordi n. sp. (female) differs from P. foliosetis Jack, 1961 by the shape of the idiosoma which is much wider than long (vs. rounded idiosoma in P. foliosetis), the presence of 110–139 pairs of the dorsal anterolateral setae (vs. presence of about 35 pairs of these setae), 20–26 pairs of the peripheral setae (vs. 10–19 pairs), 3 pairs of the genital setae (vs. 1 pair), 6 pairs of the pseudoanal setae (vs. 4 pairs), the absence of leg setae vGII and presence of setae vGIV (vs. presence of setae vGII and absence of setae vGIV). P. balochistani n. sp. (female) differs from P. persicum Hirst, 1917 by the chelicerae 325–350 long (vs. 190–230 long in P. persicum), the fixed cheliceral digit bearing small tines (vs. spinous fixed cheliceral digit), presence of subcapitular setae n (vs. absence of setae n), serrate peripheral setae (vs. smooth peripheral setae), presence of leg setae vGII–III (vs. absence of setae vGII–III), 4 pairs of the genital setae (vs. 3 pairs) and 7 pairs of the pseudoanal serrate setae (vs. 9–11 pairs of filiform setae ps). [ABSTRACT FROM AUTHOR]

Aim Size is one of the most important and obvious traits of an organism. Both small and large sizes have adaptive advantages and disadvantages. Body size-frequency distributions of most large clades are unimodal and right skewed. Species larger than the mean or range midpoint of body sizes are relatively scarce. Theoretical models suggest evolutionary rates are higher in small organisms with short generation times. Therefore diversification rates are usually thought to be maximal at relatively small body sizes. Empirical studies of the rates of molecular evolution and clade diversification, however, have usually indicated that both are unrelated to body size. Furthermore, it has been claimed that because snakes are longer than lizards, the size-frequency distribution of all squamate species is bimodal overall. We examined the shape of the size-frequency distribution of nearly all Squamata and Rhynchocephalia species, and investigated how size affected diversification rates. Location Global. Methods We collected data on maximum body length for 9805 lepidosaur (squamates and the tuatara) species (99.7% of all species) and converted them to mass using clade-specific allometric equations. Using methods that test for relationships between continuous traits and speciation and extinction rates on a large, dated phylogeny (4155 species), we investigated the relationship between diversification rates and body size. Results Living squamates span six orders of magnitude in body size, eight when giant extinct snakes and mosasaurs are included. The body size-frequency distributions of snakes and lizards separately, and of all lepidosaur species combined, are unimodal and right skewed. Nonetheless, we find neither linear nor hump-shaped relationships between size and diversification rates, except in snakes, where speciation and diversification are hump shaped. Main conclusions Despite a clear modality and skew in the body sizes of lepidosaurs, we find little evidence for faster diversification of modal-sized taxa, perhaps implying that larger-sized clades are relatively young. [ABSTRACT FROM AUTHOR]

The existence of elaborate ornamental structures in males is often assumed to reflect the outcome of female mate choice for showy males. However, female mate choice appears weak in many iguanian lizards, but males still exhibit an array of ornament-like structures around the throat. We performed a phylogenetic comparative study to assess whether these structures have originated in response to male-male competition or the need for improved signal efficiency in visually difficult environments. We found little evidence for the influence of male-male competition. Instead, forest species were more likely to exhibit colourful throat appendages than species living in open habitats, suggesting selection for signal efficiency. On at least three independent occasions, throat ornamentation has become further elaborated into a large, conspicuously coloured moving dewlap. Although the function of the dewlap is convergent, the underlying hyoid apparatus has evolved very differently, revealing the same adaptive outcome has been achieved through multiple evolutionary trajectories. More generally, our findings highlight that extravagant, ornament-like morphology can evolve in males without the direct influence of female mate choice and that failure to consider alternative hypotheses for the evolution of these structures can obscure the true origins of signal diversity among closely related taxa. [ABSTRACT FROM AUTHOR]

Reptilian skin is tough and scaled representing an evolutionary adaptation to the terrestrial environment. The presence of sulfhydryl oxidase during the process of hardening of the corneous layer in reptilian epidermis has been analyzed by immunocytochemistry and immunoblotting. Sulfhydryl oxidase-like immunoreactivity of proteins in the 50-65 kDa range of molecular weight is mainly observed in the transitional and pre-corneous layers of crocodilians, chelonian, and in the forming beta-layer of lepidosaurians. The ultrastructural localization of the enzyme by immunogold in lizard epidermis during renewal and resting stages shows that the labeling is mainly distributed in the cytoplasm and along the accumulating beta-packets of differentiating beta-cells while it appears very low to undetectable in differentiating alpha-cells of the lacunar, clear, mesos, and alpha-layers. The labeling however becomes absent or undetectable also in the fully mature beta-layer. The study shows that an oxidative enzyme is likely responsible of the cross-linking of the numerous cysteines present in the main proteins accumulated in corneocytes of reptilian epidermis, known as corneous beta-proteins (beta-keratins). This process of disulphide bond formation is probably largely responsible for the formation of hard beta-corneous layers in reptilian scales, a difference with alpha-corneous layers where substrate proteins of transglutaminase appear predominant. [ABSTRACT FROM AUTHOR]

The article focuses on the retroviral envelope proteins in placentogenesis of lizards. It discusses the Deoxyribonucleic acid (DNA) copy from ribonucleic acid (RNA) genome through reverse transcriptase, RNA sequence in the lizard's placenta with syncytins and immunosuppressive activity in retroviruses and viral transmembrane envelope proteins.

We explored individual variation and asymmetry in the skull shape of the common wall lizard (Podarcis muralis Laurenti, 1768) across four populations representing different habitats, by employing geometric morphometrics. We found directional and fluctuating asymmetry across the analysed populations, without differences in fluctuating asymmetry among populations. Patterns of individual variation and fluctuating asymmetry were highly correlated within and among populations. Asymmetric skull shape variation was similar in all populations, and was mostly related to the jaw adductor muscle chamber. Our results imply that the uniform pattern of skull fluctuating asymmetry results from a high level of canalisation. Directional asymmetry can be related to anatomical and behavioural lateralisation. [ABSTRACT FROM AUTHOR]

Scincine lizards in Madagascar form an endemic clade of about 60 species exhibiting a variety of ecomorphological adaptations. Several subclades have adapted to burrowing and convergently regressed their limbs and eyes, resulting in a variety of partial and completely limbless morphologies among extant taxa. However, patterns of limb regression in these taxa have not been studied in detail. Here we fill this gap in knowledge by providing a phylogenetic analysis of DNA sequences of three mitochondrial and four nuclear gene fragments in an extended sampling of Malagasy skinks, and microtomographic analyses of osteology of various burrowing taxa adapted to sand substrate. Based on our data we propose to (i) consider Sirenoscincus Sakata & Hikida, 2003, as junior synonym of Voeltzkowia Boettger, 1893; (ii) resurrect the genus name Grandidierina Mocquard, 1894, for four species previously included in Voeltzkowia; and (iii) consider Androngo Brygoo, 1982, as junior synonym of Pygomeles Grandidier, 1867. By supporting the clade consisting of the limbless Voeltzkowia mira and the forelimb-only taxa V. mobydick and V. yamagishii, our data indicate that full regression of limbs and eyes occurred in parallel twice in the genus Voeltzkowia (as hitherto defined) that we consider as a sand-swimming ecomorph: in the Voeltzkowia clade sensu stricto the regression first affected the hindlimbs and subsequently the forelimbs, whereas the Grandidierina clade first regressed the forelimbs and subsequently the hindlimbs following the pattern prevalent in squamates. Timetree reconstructions for the Malagasy Scincidae contain a substantial amount of uncertainty due to the absence of suitable primary fossil calibrations. However, our preliminary reconstructions suggest rapid limb regression in Malagasy scincids with an estimated maximal duration of 6 MYr for a complete regression in Paracontias, and 4 and 8 MYr respectively for complete regression of forelimbs in Grandidierina and hindlimbs in Voeltzkowia. [ABSTRACT FROM AUTHOR]

In many animal taxa, coloration is a visual signal used for communication among conspecifics, for example between age classes. Juvenile coloration has been hypothesized to reduce aggression from adults in some species, in what is called the aggression avoidance hypothesis. Spiny-footed lizards are good subjects for testing this hypothesis, as juveniles develop conspicuous red coloration on their hind limbs and tails that fades in adulthood. To test the influence of juvenile coloration on adult aggressiveness, we conducted videotaped encounters in captivity between adults of both sexes and juveniles with their natural red coloration, or experimentally painted either red or white on their natural red parts. Then we recorded the number of times juveniles were bitten and attacked. In unpainted juveniles, no significant relationship was found between juvenile coloration (brightness, red chroma or hue) and adult aggressiveness. However, juveniles painted red were bitten less than those painted white when number of times bitten was controlled for number of times attacked. This result supports the aggression avoidance hypothesis, as an escalation from low-intensity (attacking) to high-intensity aggression (biting) was less probable towards red juveniles. The presence of red coloration in juveniles caused the reduction in adult aggression, while small natural variations in this red colour did not seem to have any further effect. Juvenile red coloration in this species might indicate age or sexual immaturity to adults. [ABSTRACT FROM AUTHOR]

Nestin has been considered a neural stem cell marker, and represents an intermediate filament protein likely involved in restructuring the cytoskeleton in different cell types. The present ultrastructural study has immunodetected nestin especially in the wound epidermis, regenerating myotubes and in the growing nerves of the regenerating tail of lizards. In keratinocytes of the stratified wound epidermis nestin is present in the irregular electron-paler meshwork located along the cell perimeter and among keratin bundles converging into desmosomes. In the regenerating muscles nestin-immunoreactivity remains confined to some external regions along the myotubes and in the cytoplasmic ends of the myotubes not occupied by myofibrils. A diffuse nestin immunolabeling is also present among the neurofilaments of growing axons, in Schwann cells and in ependymal cells of the regenerating spinal cord of the tail. The localization of nestin in sites of cytoskeletal remodeling in keratinocytes, myotubes, ependymal cells and axons, suggests that this protein is associated to the reassembling of keratin tonofilaments in moving keratinocytes, assembling of contractile proteins in myotubes, and in the organization of neurofilaments during the growth and myelination of axons within the regenerating lizard tail. [ABSTRACT FROM AUTHOR]

A record of an adult Large Striped Skink Ctenotus robustus, from the northern outskirts of metropolitan Melbourne, with four regenerating tails is described. The rarity of this record is confirmed with reference to other field surveys and published studies. [ABSTRACT FROM AUTHOR]

We describe sexual dimorphism in coloration, size, and shape in 48 specimens (19 males and 29 females) of the bridled skink, Trachylepis vittata (Olivier, 1804), collected from western regions of the Iranian Plateau. For the analyses, we used 29 metric and 9 meristic characters. Our study showed the existence of slight sexual size dimorphism in body and head size between the sexes. Males had significantly smaller heads and narrower bodies than females. Furthermore, males and females were different in the structure of the cloaca. The possible scenarios behind sexual dimorphism in this lizard are discussed. [ABSTRACT FROM AUTHOR]

Animals communicate via a variety of sensory channels and signals. Studies on acoustic and visual communication systems suggest that differences in the physical environment contribute to the variety of signalling behaviour, with species investing in those signals that are transmitted best under the local conditions. Whether or not environmental tuning also occurs in chemical communication systems has received much less attention. In the present study, we examined the effect of several aspects of the physical environment on the chemical communication system of lacertid lizards (family Lacertidae). The numbers of femoral pores are used as a proxy reflecting how much a particular species invests in and relies upon chemical signalling. Femoral pores are specialized epidermal structures that function as a secretion channel for the waxy substance produced by glands. In some lacertid species, the secretion carries infochemicals that play an important role in social communication. The number of femoral pores varies considerably among species. We have compiled data on femoral pore numbers for 162 species and tested for the effects of climate and substrate use. After correcting for body size and taking the phylogenetic relationships among the species into account, we found no effect of climate conditions or latitude on species pore numbers. Substrate use did affect pore numbers: shrub-climbing species tended to have fewer femoral pores than species inhabiting other substrates. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114, 44-57. [ABSTRACT FROM AUTHOR]

Visual communication is important in many lizard species. One conspicuous visual signal is the headbob display, which consists of a stereotyped up and down movement of the head and/or torso. We analysed male headbob displays in the neotropical lizard, Liolaemus pacha, in its natural environment. Our objectives were to describe and analyse the structure and form of these headbob displays and to relate these to two social contexts: male without an apparent receiver (MA context) and male responding to another male (MM context). We measured duration of each headbob bout, its maximum amplitude, duration of intervals, number of headbob bouts and presence or absence of three modifiers (gular inflation, back arching and lateral compression). We found two types of triple headbob displays, corresponding to what has been previously reported as the challenge headbob and the broadcast headbob display. Duration and maximum amplitude were significantly greater in headbob displays in the MM context compared to the MA context. We did not observe modifiers when a male was in the MA context but there was at least one modifier present in the MM context. [ABSTRACT FROM AUTHOR]

A new fossil lizard of the genus Pachygenys is described on the basis of a single, partially broken right mandible excavated from an unnamed formation of the Lower Cretaceous Sasayama Group in Hyogo Prefecture, western Honshu, Japan. The mandible exclusively shares a few apparently highly specialized morphological features, such as distinct foreshortening of the dentary tooth row and reduced dentary tooth number (nine), with Pachygenys thlastesa, the type species of the genus from the Lower Cretaceous of eastern China. However, the new species differs from the latter in having a shorter tooth row, anterior and middle teeth with unicuspid crowns (vs. bluntly truncated crowns in the latter), and posterior teeth with unicuspid and simple conical crowns (vs. bluntly truncated crowns in the latter). The specimen described here represents the first unequivocal fossil record of lizards in Japan, with its congeneric species occurring almost concurrently in eastern Eurasia. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism (SSD) is often assumed to reflect the phenotypic consequences of differential selection operating on each sex. Species that exhibit SSD may also show intersexual differences in other traits, including field-active body temperatures, preferred temperatures, and locomotor performance. For these traits, differences may be correlated with differences in body size or reflect sex-specific trait optima. Male and female Yarrow's spiny lizards, Sceloporus jarrovii, in a population in southeastern Arizona exhibit a difference in body temperature that is unrelated to variation in body size. The observed sexual variation in body temperature may reflect divergence in thermal physiology between the sexes. To test this hypothesis, we measured the preferred body temperatures of male and female lizards when recently fed and fasted. We also estimated the thermal sensitivity of stamina at seven body temperatures. Variation in these traits provided an opportunity to determine whether body size or sex-specific variation unrelated to size shaped their thermal physiology. Female lizards, but not males, preferred a lower body temperature when fasted, and this pattern was unrelated to body size. Larger individuals exhibited greater stamina, but we detected no significant effect of sex on the shape or height of the thermal performance curves. The thermal preference of males and females in a thermal gradient exceeded the optimal temperature for performance in both sexes. Our findings suggest that differences in thermal physiology are both sex- and size-based and that peak performance at low body temperatures may be adaptive given the reproductive cycles of this viviparous species. We consider the implications of our findings for the persistence of S. jarrovii and other montane ectotherms in the face of climate warming. [ABSTRACT FROM AUTHOR]

The gekkonidUroplatusexhibits many autapomorphic features. The laryngotracheal region has long been noted to display unusual characteristics, with a widely expanded and membrane-roofed anterior portion of the trachea being prominent among these. It has been proposed that this tracheal expansion serves as a reservoir for pressurised air that is explosively released and provides the energy for the loud distress calls released by these lizards. To determine whether this hypothesis is supported by associated anatomical features, we examined the laryngotracheal region in more detail, for 6 of 14 of the species within the genus, and compared the results to what is known of the laryngotracheal anatomy of Afro-Malagasy geckos. The muscles of the gular region, and the form and dimensions of the trachea, larynx and their adnexa, are described. Modifications of the gular muscles and their attachments render the larynx ofUroplatusmore mobile in the oropharyngeal region, and in large-bodied taxa (U. lineatus, U. sikorae) the trachea exhibits the degree of expansion previously observed forU. fimbriatus. In these taxa the paired gular muscles fail to meet in the ventral midline and are, instead, bridged by fascial sheets. These modifications are consistent with ventral displacement of the anterior terminus of the trachea when charged with pressurised air, prior to the opening of the glottal valve and the release of a loud, harmonically-unstructured and explosive distress call. Such calls are likely directed at avian and mammalian predators to induce a startle response. The range of anatomical form of the laryngotracheal region exhibited withinUroplatusprovides insights into the variation of laryngotracheal structure, such as incomplete tracheal rings and a conical trachea, which are exhibited by other Afro-Malagasy geckos. [ABSTRACT FROM PUBLISHER]

One of the most remarkable hand movements is grasping. This ability has been repetitively associated with the evolution of the human lineage towards the development of technology. Besides mammals, other tetrapods have also evolved significant, and in some cases surprising, forelimb prehensile capabilities. In this study, we present a qualitative analysis of the carpal bones in diverse lizard taxa. Our main goal is to make a survey of the carpal morphology of different squamatans and to interpret its variability in the context of both lizard skilled forelimb movements and the evolutionary history of Squamata. [ABSTRACT FROM AUTHOR]

Paroedura hordiesi sp. n. is described from Montagne des Français, a karstic limestone massif in the far north of Madagascar recently established as nature reserve. The new species has the nostril in contact with the rostral scale and shares many characters with P. karstophila and especially with P. homalorhina which are also restricted to karstic habitats. Paroedura hordiesi differs from P. karstophila by a smoother skin on dorsum and legs, by original and regenerated tails being both entirely smooth, by colouration, and by larger snout-vent length. Morphologically the new species is most similar to P. homalorhina from the Ankarana reserve from which it can be distinguished by shorter limbs and a less slender habitus. Published molecular data place the new species as close relative of P. homalorhina and another undescribed species from Nosy Hara Island, while newly determined data of the cox1 gene for P. karstophila confirm the distinctness of the new species from this taxon. Integrating the information from published and novel molecular data, the new species differs from all nominal Paroedura (except P. vahiny for which no molecular data are available to date) by strong genetic divergences. P. hordiesi might be another microendemic species of the Montagne des Français region. We suggest its IUCN Red List classification as "Critically Endangered" on the basis that it has an extent of occurrence of at most 50 km, it is known from a single location, and there is a continuing decline in the extent and quality of its habitat. [ABSTRACT FROM AUTHOR]

Sexual dimorphism is a common phenomenon in lizards of the genus Sceloporus, this allows to identify differences in body size, and morphological design between males and females. Usually a variation occurs in color dissociated from the morphology. Using one-way ANOVA and discriminant analysis, we obtained significant differences in six morphological traits correlated with throat color, allowing the recognition of three different phenotypes (yellow, blue and orange). However, we did not observe differences in microhabitat use. Males with blue throat (44.35%) were the largest and the most robust, and have a similar abundance as males with yellow throat (48.5%). Males with orange throats only represented 8% of the total. We suggest that males' selection mechanisms by females and the opportunities for copulation, by the three morphs, can induce changes in reproductive investment between locations. We suggest that morphological characteristics are an important factor to consider in studies on reproductive investment of species. [ABSTRACT FROM AUTHOR]

ABSTRACT Anolis lizards are an emerging model system for the study of limb development and evolution, but very little is known concerning the regulatory interactions that control limb patterning differences among Anolis species or what regulatory interactions are deeply conserved between Anolis and other tetrapod groups. Here we report the establishment of an embryonic limb micromass culture system that enables functional studies of forelimb and hindlimb gene regulatory networks in Anolis. Characterization of this culture system demonstrated that embryonic forelimb and hindlimb micromasses from different Anolis species are easy to sustain in culture for weeks, and the expression of forelimb and hindlimb-specific gene expression patterns are maintained for at least 8 days in culture. We tested the ability of this system to explore regulatory linkages between transcription factors and their putative target genes through the ectopic expression of a hindlimb-specific transcription factor, pitx1, in forelimb micromasses. We found that pitx1 expression in forelimb cells is sufficient to strongly induce the expression of hoxc11, a gene that normally exhibits hindlimb-restricted expression. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 156-165, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Rock-dwelling lizards are hypothesized to be highly constrained in the evolution of head morphology and, consequently, bite force. Because the ability to generate a high bite force might be advantageous for a species' dietary ecology, morphological changes in head configuration that allow individuals to maintain or improve their bite force under the constraint of crevice-dwelling behaviour are to be expected. The present study addressed this issue by examining head morphology, bite force, and a number of dietary traits in the rock-dwelling cordylid lizards Ouroborus cataphractus and Karusasaurus polyzonus. The results obtained show that O. cataphractus has a larger head and higher bite force than K. polyzonus. In K. polyzonus, head width, lower jaw length, and jaw closing-in lever are the best predictors of bite force, whereas head height is the main determinant of bite force in O. cataphractus. Although the observed difference in bite force between the species does not appear to be related to dietary patterns or prey handling, the prey spectrum available for intake was greater in O. cataphractus compared to K. polyzonus. We discuss the influence of interspecific differences in anti-predator morphology on head morphology and bite force in these rock-dwelling species. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 823-833. [ABSTRACT FROM AUTHOR]

Abstract: The presence and localization of cathelicidin anti-microbial peptides in the lizard, Anolis carolinensis, were investigated by immunocytochemistry. The study showed that immunoreactivity for cathelicidins 1 and 2 was only present in large granules of heterophilic–basophilic granulocytes, rarely found in the dermis and sub-dermal muscle in normal and more frequently in wound and regenerating skin tissues or in the blood. Some immunopositive granulocytes were also observed among the keratinocytes of the wound epithelium covering the tail stump and occasionally in the regenerating epidermis of the tail. Immunolabeling for cathelicidins was also seen in low electrondense amorphous material present on the surface of the wound epidermis and on the plasma membrane of bacteria present on the surface of corneocytes of the epidermis. Immunolabeling for cathelicidins was absent in the other cell types and in control sections. The study suggests that cathelicidins are normally stored in granulocytes in the blood or in connective tissues, while keratinocytes can be stimulated to produce and possibly release these molecules only after injury or microbial invasion. [Copyright &y& Elsevier]