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Objective: To report ophthalmic examination, biometry, phenol red thread test (PRTT), intraocular pressure (IOP), and histologic findings from a private collection of inland bearded dragons (Pogona vitticeps). Animals studied: Fourteen inland bearded dragons. Procedures: Complete ophthalmic examinations were performed on all animals, including slit‐lamp biomicroscopy, indirect ophthalmoscopy, fluorescein stain, phenol red thread test, and rebound tonometry. B‐mode ultrasonography was used to measure anterior chamber depth, axial lens thickness, vitreal chamber depth, and axial globe length. Horizontal corneal diameter was estimated using ImageJ software. Histologic assessment was obtained for one of the bearded dragons that died following the study period. Results: The median PRTT value was 7.27 mm/15 seconds. Mean IOP was 6.29 ± 1.60 mm Hg and 2.14 ± 1.37 mm Hg using the dog and undefined calibration settings, respectively. Median axial globe length was 11.75 mm. Mean anterior chamber depth and mean lens thickness were 2.06 ± 0.35 mm and 3.38 ± 0.45 mm, respectively. Median vitreal chamber depth was 6.79 mm. Mean horizontal corneal diameter was 5.138 ± 0.346 mm. Two distinct ocular phenotypes were observed, with two of the bearded dragons having corneal globosa, deep anterior chambers, and tufts of iridal vessels and fibrillar material extending into the anterior chamber. Conclusions: The ultrasound biometry, PRTT, and rebound tonometry results may serve as a guideline for ophthalmic parameters in healthy bearded dragons. Examination and testing of greater numbers of animals are necessary to establish true reference ranges and determine if the observed ocular phenotypes represent normal variants or pathologic changes. [ABSTRACT FROM AUTHOR]

Sex‐related differences in morphology and behavior are well documented, but the relative contributions of genes and environment to these traits are less well understood. Species that undergo sex reversal, such as the central bearded dragon (Pogona vitticeps), offer an opportunity to better understand sexually dimorphic traits because sexual phenotypes can exist on different chromosomal backgrounds. Reproductively female dragons with a discordant sex chromosome complement (sex reversed), at least as juveniles, exhibit traits in common with males (e.g., longer tails and greater boldness). However, the impact of sex reversal on sexually dimorphic traits in adult dragons is unknown. Here, we investigate the effect of sex reversal on bite‐force performance, which may be important in resource acquisition (e.g., mates and/or food). We measured body size, head size, and bite force of the three sexual phenotypes in a colony of captive animals. Among adults, we found that males (ZZm) bite more forcefully than either chromosomally concordant females (ZWf) or sex‐reversed females (ZZf), and this difference is associated with having relatively larger head dimensions. Therefore, adult sex‐reversed females, despite apparently exhibiting male traits as juveniles, do not develop the larger head and enhanced bite force of adult male bearded dragons. This pattern is further illustrated in the full sample by a lack of positive allometry of bite force in sex‐reversed females that is observed in males. The results reveal a close association between reproductive phenotype and bite force performance, regardless of sex chromosome complement. Research Highlights: Bite‐force in bearded dragon lizards reflects sexual phenotype not chromosome complement Temperature induced sex‐reversed females (ZZf) resemble concordant females (ZWf) Males (ZZm) show greater bite‐force, larger heads, and allometric scaling. [ABSTRACT FROM AUTHOR]

In bearded dragons, aneurysms are most commonly observed on the head and neck and in the cranial coelom. A nine-year-old male bearded dragon (Pogona vitticeps) was presented for a ventral tail base swelling. Aspiration yielded frank blood, and Doppler ultrasonography confirmed an aneurysm by demonstrating pulsatile jets into the lumen. Three months later, the animal presented for acute regurgitation and tenesmus. Coelomic ultrasound showed a distended stomach and pyloroduodenal intussusception. An exploratory coeliotomy revealed a tortuous and distended ventral abdominal vein and mesenteric vasculature. The colon and cecum were markedly distended, and intracoelomic blood clots were discovered. Euthanasia was performed. Necropsy revealed a tail base aneurysm, presumably arterial. The walls of the aneurysm exhibited osseous metaplasia and smooth muscle replacement by fibrous connective tissue with no infectious organisms. This case report provides information on a differential diagnosis for tail base swellings in bearded dragons. [ABSTRACT FROM AUTHOR]

A 0.5-kg, 9-yr-old, male central bearded dragon (Pogona vitticeps) presented with a proliferative mass (0.4 3 0.2 inches) on the left rostral aspect of the lower lip. Physical examination, blood work, and whole-body radiography did not reveal any other abnormalities. Histopathology confirmed squamous cell carcinoma. Considering the small size of the tumor, absence of deep tissue infiltration, and its radioresponsive characteristics, iridium 192 high dose rate brachytherapy was attempted. The dragon initially received three doses of 4 Gy/site at days 0, 7, and 17. Recurrence developed 3 mo later. Three more fractions of 6 Gy/site at days 0, 7, and 14 were delivered according to the same procedure. A second recurrence appeared after 2 mo. Surgical excision was then performed, followed by four fractions of 6 Gy/site on the surgical site at 2-wk intervals. Sixteen months posttreatment, no recurrence of the mass was observed. [ABSTRACT FROM AUTHOR]

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Central bearded dragons, Pogona vitticeps, are ectothermic heliotherms native to dry and arid regions and are often kept as exotic pets in colder less arid countries. They do however, often fall sick resulting in sudden death. This is now known to be caused by bacterial infections such as Listeria monocytogenes and Porphyromonas pogonae sp. This study therefore, aimed to identify microorganisms present in the buccal cavity of the central bearded dragon (P. vitticeps) in Namibia. In order to achieve this, oral swabs were taken from a bearded dragon found in a garden in Windhoek, Namibia and grown in nutrient agar. Colony morphology was described before Gram’s staining to differentiate the bacteria. The automated VITEK®2 system was used to identify the bacteria. On nutrient agar, opaque yellow circular colonies were observed after 24hrs incubation at 37°C. A gram-positive coccus shaped bacteria was observed. VITEK®2 analysis identified the bacteria as Micrococcus luteus. There has not been a study on the microbiota of the buccal cavity of the central bearded dragon in Namibia. [ABSTRACT FROM AUTHOR]

A 0.5 kg, 5-yr-old male bearded dragon (Pogona vitticeps) presented with a 2-mo history of lethargy, anorexia, and impaired locomotion. Upon physical examination, bradyarrhythmia (heart rate: 20 beats/min) and balance disorders were noted. Electrocardiography revealed a first-degree atrioventricular block (P-R interval: 360 ms). On echocardiography, all cardiac chambers were slightly above normal ranges. Complete blood count, blood biochemistry, and T4 were unremarkable except for mildly elevated aspartate aminotransferase. Adenovirus testing was negative by polymerase chain reaction. Following euthanasia, necropsy revealed marked thickening of the arterial trunks and histopathology confirmed multifocal atherosclerosis of efferent heart vessels, arteriosclerosis of cerebral arterioles, and multifocal spongiosis of brain tissue, more pronounced in the optic chiasma. Owing to its severity, atherosclerosis may have contributed to chronic arterial hypertension with damages to the heart, brain vessels, and brain tissue-optic chiasma. [ABSTRACT FROM AUTHOR]

Isospora amphiboluri is a common coccidian found in captive bearded dragons (Pogona vitticeps). To minimize the impact of this parasite, it is important to characterize its pathogenesis so that we can develop appropriate methods for diagnosis and treatment. Forty-five juvenile bearded dragons were used for this two-part study. In the first part, ten bearded dragons were infected with 20,000 oocysts per os, while a control group of five animals received only water. Feces were collected over 45 days and screened for oocysts. In the second part, thirty bearded dragons were used to characterize the pathogenesis of I. amphiboluri. Twenty-five bearded dragons were infected as described previously, while five animals served as controls. Five infected bearded dragons and one control were humanely euthanized on days 4, 8, 12, 16, and 20 post-infection for complete necropsies. The pre-patent period for I. amphiboluri was found to be 18.6 ± 1.9 days (range 15–22 days). Histopathology confirmed that I. amphiboluri follows a homoxenous life cycle. Infections begin in the duodenum and progress to the colon over time. The findings of this study can be used to develop better quarantine and treatment protocols for captive bearded dragons.

Reptiles are popular as pets and it is, therefore, important to understand how different aspects of housing and husbandry impact on their behaviour and welfare. One potential cause of stress in captive reptiles is interaction with humans; in particular, the effect of handling. However, little research on handling has been carried out with reptiles, particularly relating to the type of gentle handling likely to be experienced by pet animals. The aim of this study was therefore to determine whether the amount of time that bearded dragons (Pogona vitticeps), a commonly kept pet species, experienced gentle handling induced no or differing levels of anxiety, as reflected in their subsequent behavioural response to novelty. We found that there appeared to be a mildly aversive effect of handling time on subsequent behavioural response to novelty. Longer durations of handling (5 min or 15 min) appeared to increase anxiety-related behaviour, with handled animals showing more frequent tongue flicking behaviour when they experienced a novel environment and reduced time spent in close proximity to a novel object. These results suggest that handling bearded dragons, even in a gentle way, may increase their anxiety. However, it is not yet known whether animals may habituate to handling for longer periods if provided with additional experience.

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution.

Although diurnal animals displaying monophasic sleep patterns exhibit periodic cycles of alternating slow-wave sleep (SWS) and rapid eye movement sleep (REMS), the regulatory mechanisms underlying these regular sleep cycles remain unclear. Here, we report that in the Australian dragon Pogona vitticeps exposed to constant darkness (DD), sleep behavior and sleep-related neuronal activity emerged over a 24-h cycle. However, the regularity of the REMS/SWS alternation was disrupted under these conditions. Notably, when the lizards were then exposed to 12 h of light after DD, the regularity of the sleep stages was restored. These results suggest that sleep-related neuronal activity in lizards is regulated by circadian rhythms and that the regularity of REMS and SWS cycling is influenced by daytime light exposure., (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)

Fungal infections in captive as well as in free-living reptiles caused by emerging obligate pathogenic fungi appear with increasing frequency and give occasion to establish new and fast methods for routine diagnostics. The so-called yellow fungus disease is one of the most important and common fungal dermatomycoses in central bearded dragons (Pogona vitticeps) and green iguanas (Iguana iguana) and is caused by Nannizziopsis guarroi. The aim of this study was to prove reliability in identification of N. guarroi with Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in comparison to molecular biological analysis of ribosomal DNA genes. In seven lizards from three different species, including central bearded dragons, green iguanas, and a European green lizard (Lacerta viridis), dermatomycoses caused by N. guarroi were diagnosed by isolation of the fungal pathogen as well as histopathological confirmation of the granulomatous inflammatory reaction in deep skin biopsies. With this survey, we proved that MALDI-TOF MS is a diagnostic tool for accurate identification of N. guarroi. Besides small subunit 18S rDNA (SSU) and internal transcribed spacer (ITS)1-5.8S rDNA, a large fragment of the large subunit of the 28S rDNA (LSU), including the domain (D)1 and D2 have been sequenced, for phylogenetical analysis. Large fragment of the LSU from N. guarroi has been sequenced for the first time. Yellow fungus disease in a European lizard species is described for the first time to our knowledge as well, which could be of importance for free-ranging populations of European lizards. [ABSTRACT FROM AUTHOR]

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution. [ABSTRACT FROM AUTHOR]

Invertebrate iridoviruses (IIVs), while mostly described in a wide range of invertebrate hosts, have also been repeatedly detected in diagnostic samples from poikilothermic vertebrates including reptiles and amphibians. Since iridoviruses from invertebrate and vertebrate hosts differ strongly from one another based not only on host range but also on molecular characteristics, a series of molecular studies and bioassays were performed to characterize and compare IIVs from various hosts and evaluate their ability to infect a vertebrate host. Eight IIV isolates from reptilian and orthopteran hosts collected over a period of six years were partially sequenced. Comparison of eight genome portions (total over 14 kbp) showed that these were all very similar to one another and to an earlier described cricket IIV isolate, thus they were given the collective name lizard−cricket IV (Liz−CrIV). One isolate from a chameleon was also subjected to Illumina sequencing and almost the entire genomic sequence was obtained. Comparison of this longer genome sequence showed several differences to the most closely related IIV, Invertebrate iridovirus 6 (IIV6), the type species of the genus Iridovirus, including several deletions and possible recombination sites, as well as insertions of genes of non-iridoviral origin. Three isolates from vertebrate and invertebrate hosts were also used for comparative studies on pathogenicity in crickets (Gryllus bimaculatus) at 20 and 30 °C. Finally, the chameleon isolate used for the genome sequencing studies was also used in a transmission study with bearded dragons. The transmission studies showed large variability in virus replication and pathogenicity of the three tested viruses in crickets at the two temperatures. In the infection study with bearded dragons, lizards inoculated with a Liz−CrIV did not become ill, but the virus was detected in numerous tissues by qPCR and was also isolated in cell culture from several tissues. Highest viral loads were measured in the gastro-intestinal organs and in the skin. These studies demonstrate that Liz−CrIV circulates in the pet trade in Europe. This virus is capable of infecting both invertebrates and poikilothermic vertebrates, although its involvement in disease in the latter has not been proven.

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty-two newly hatched bearded dragons (<24 h old) were allocated to six treatment groups ( n = 7 per group). Five groups were exposed to different UVb compact lamps for two hours per day, with a control group not exposed to UVb radiation. At 120 days of age, blood samples were obtained and concentrations of 25( OH)D3, Ca, P and uric acid were determined. In addition, plasma 25( OH)D3 concentration was determined in free-living adult bearded dragons to provide a reference level. Only one treatment resulted in elevated levels of 25( OH)D3 compared to the control group (41.0 ± 12.85 vs. 2.0 ± 0.0 nmol/L). All UVb-exposed groups had low 25( OH)D3 plasma levels compared to earlier studies on captive bearded dragons as well as in comparison with the free-living adult bearded dragons (409 ± 56 nmol/L). Spectral analysis indicated that all treatment lamps emitted UVb wavelengths effective for some cutaneous vitamin D synthesis. None of these lamps, under this regime, appeared to have provided a sufficient UVb dose to enable synthesis of plasma 25( OH)D3 levels similar to those of free-living bearded dragons in their native habitat. [ABSTRACT FROM AUTHOR]

Anesthesia is an essential part of veterinary care for reptiles; however, there is limited literature available for the anesthetic management of commonly kept species such as the bearded dragon ( Pogona vitticeps). This study compares the intravenous use of 10 mg/kg propofol with 12 mg/kg alfaxalone. Both protocols resulted in smooth and rapid induction and subsequent intubation. A surgical plane of anesthesia, defined as a loss of reaction to noxious stimuli and absent muscle tone, was achieved in 5/8 (62.5%) alfaxalone animals and 0/8 of the propofol animals. Reflexes and muscle tone were regained from a cranial to caudal direction. There was no effect on the heart rate; however, both protocols resulted in respiratory depression, including 5 and 20 min durations of apnea in two of the alfaxalone animals. Differences in the characteristics of these two protocols are likely attributable to the different depths of anesthesia achieved. Further research is required to establish equipotent dosages to allow rigorous comparison. In conclusion, both agents at these dosages were effective and safe for inducing anesthesia and appeared to show dose dependent effects on respiration and duration of anesthesia. [ABSTRACT FROM AUTHOR]

Metarhizium ( M. ) granulomatis (formerly Chamaeleomyces granulomatis ) invariably causes fatal fungal glossitis and systemic mycosis in veiled chameleons ( Chamaeleo calyptratus ). Isolation of M. granulomatis in other lizards thus far has not been described. The aim of this study therefore was to obtain information on the presence of M. granulomatis in reptiles kept as pets, and to examine whether there was an association between specific genotypes and clinical/pathological outcomes. Besides 18S ribosomal (r) DNA (SSU) and internal transcribed spacer1-5.8S (ITS1-5.8S) rDNA, a fragment of the large subunit of the 28S rDNA (LSU), including the domains 1 (D1) and D2, were sequenced for identification of the fungus and phylogenetic analysis. Metarhizium granulomatis was isolated from 23 veiled chameleons, two panther chameleons ( Furcifer pardalis ) and one central bearded dragon ( Pogona vitticeps ). Only the veiled chameleons revealed corresponding pathological findings in the form of glossal hemorrhage, granulomatous glossitis, pharyngitis, dermatitis and/or visceral mycosis. The infection site correlated to survival times of infected veiled chameleons. Combined long-term treatment with terbinafine and nystatin based on susceptibility testing may be helpful for prevention of disease and visceral spreading of the fungus, but elimination of the fungal pathogen or successful treatment of diseased veiled chameleons have not been achieved yet. Sequencing of the ribosomal genes yielded five different genotypes, with genotype A being strongly correlated with dermatitis, and remaining genotypes with pharyngitis and glossitis. However, disseminated visceral mycosis developed irrespective of the genotypes. [ABSTRACT FROM AUTHOR]

Vertebrate sex is typically determined genetically, but in many ectotherms sex can be determined by genes (genetic sex determination, GSD), temperature (temperature-dependent sex determination, TSD), or interactions between genes and temperature during development. TSD may involve GSD systems with either male or female heterogamety (XX/XY or ZZ/ZW) where temperature overrides chromosomal sex determination to cause a mismatch between genetic sex and phenotypic sex (sex reversal). In these temperature-sensitive lineages, phylogenetic investigations point to recurrent evolutionary shifts between genotypic and temperature-dependent sex determination. These evolutionary transitions in sex determination can occur rapidly if selection favours the reversed sex over the concordant phenotypic sex. To investigate the consequences of sex reversal on offspring phenotypes, we measured two energy-driven traits (metabolism and growth) and 6 month survival in two species of reptile with different patterns of temperature-induced sex reversal. Male sex reversal occurs in Bassiana duperreyi when chromosomal females (female XX) develop male phenotypes (maleSR XX), while female sex reversal occurs in Pogona vitticeps when chromosomal males (male ZZ) develop female phenotypes (femaleSR ZZ). We show metabolism in maleSR XX was like that of male XY; that is, reflective of phenotypic sex and lower than genotypic sex. In contrast, for Pogona vitticeps, femaleSR ZZ metabolism was intermediate between male ZZ and female ZW metabolic rate. For both species, our data indicate that differences in metabolism become more apparent as individuals become larger. Our findings provide some evidence for an energetic advantage from sex reversal in both species but do not exclude energetic processes as a constraint on the distribution of sex reversal in nature., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Interleukins are a group of cytokines with complex immunomodulatory functions that are important for regulating immunity in vertebrate species. Reptiles and mammals last shared a common ancestor more than 350 million years ago, so it is not surprising that low sequence identity has prevented divergent interleukin genes from being identified in the central bearded dragon lizard, Pogona vitticeps, in its genome assembly. To determine the complete nucleotide sequences of key interleukin genes, we constructed full-length transcripts, using the Trinity platform, from short paired-end read RNA sequences from stimulated spleen cells. De novo transcript reconstruction and analysis allowed us to identify interleukin genes that are missing from the published P. vitticeps assembly. Identification of key cytokines in P. vitticeps will provide insight into the essential molecular mechanisms and evolution of interleukin gene families and allow for characterization of the immune response in a lizard for comparison with mammals. [ABSTRACT FROM AUTHOR]

Sex differences in morphology, physiology, and behaviour are caused by sex-linked genes, as well as by circulating sex-steroid levels. Thus, a shift from genotypic to environmental sex determination may create an organism that exhibits a mixture of male-like and female-like traits. We studied a lizard species (Central Bearded Dragon, Pogona vitticeps), in which the high-temperature incubation of eggs transforms genetically male individuals into functional females. Although they are reproductively female, sex-reversed dragons (individuals with ZZ genotype reversed to female phenotype) resemble genetic males rather than females in morphology (relative tail length), general behaviour (boldness and activity level), and thermoregulatory tactics. Indeed, sex-reversed 'females' are more male-like in some behavioural traits than are genetic males. This novel phenotype may impose strong selection on the frequency of sex reversal within natural populations, facilitating rapid shifts in sex-determining systems. A single period of high incubation temperatures (generating thermally induced sex reversal) can produce functionally female individuals with male-like (or novel) traits that enhance individual fitness, allowing the new temperature-dependent sex-determining system to rapidly replace the previous genetically based one. [ABSTRACT FROM AUTHOR]

Background: The lizards of the family Agamidae are one of the most prominent elements of the Australian reptile fauna. Here, we present a genomic resource built on the basis of a wild-caught male ZZ central bearded dragon Pogona vitticeps. Findings: The genomic sequence for P. vitticeps, generated on the Illumina HiSeq 2000 platform, comprised 317 Gbp (179X raw read depth) from 13 insert libraries ranging from 250 bp to 40 kbp. After filtering for low-quality and duplicated reads, 146 Gbp of data (83X) was available for assembly. Exceptionally high levels of heterozygosity (0.85% of single nucleotide polymorphisms plus sequence insertions or deletions) complicated assembly; nevertheless, 96.4% of reads mapped back to the assembled scaffolds, indicating that the assembly included most of the sequenced genome. Length of the assembly was 1.8 Gbp in 545,310 scaffolds (69,852 longer than 300 bp), the longest being 14.68 Mbp. N50 was 2.29 Mbp. Genes were annotated on the basis of de novo prediction, similarity to the green anole Anolis carolinensis, Gallus gallus and Homo sapiens proteins, and P. vitticeps transcriptome sequence assemblies, to yield 19,406 protein-coding genes in the assembly, 63% of which had intact open reading frames. Our assembly captured 99% (246 of 248) of core CEGMA genes, with 93% (231) being complete. Conclusions: The quality of the P. vitticeps assembly is comparable or superior to that of other published squamate genomes, and the annotated P. vitticeps genome can be accessed through a genome browser available at https://genomics.canberra.edu.au. [ABSTRACT FROM AUTHOR]

During the process of identifying a Gram-negative coccobacillus isolated from a human clinical specimen, we found that the isolate's 16S rRNA gene had very close sequence identity with that of a variant Porphyromonas isolated from polymicrobial infections in the central bearded dragon, a species of lizard [2] . The 16S rRNA gene sequences of the human isolate and of six isolates from lizards were nearly identical (99.9–100%). Phylogenetic analysis placed all of these isolates in a single phylogenetic cluster well separated from other species in the genus Porphyromonas . The closest species was Porphyromonas catoniae with 90.7–90.9% sequence identity, although there was less than 6% DNA similarity between the P. catoniae type strain and our representative isolates from lizards (PAGU 1787 T ) and human (PAGU 1776). These isolates could grow under anaerobic or microaerobic conditions (6% O 2 atmosphere). The isolates were positive for catalase and very strong β-hemolytic activity, but did not show black or brown pigmentation. Biochemically, the isolates could be differentiated from closely related species by pyroglutamic acid arylamidase and glycine arylamidase activity, and some others. The fermentation products mainly included succinic acid and propionic acid. The major fatty acids detected in cells of the isolates were iso-C15:0, anteiso-C15:0, and 3OH-iso-C17:0. The G + C content was 43.0 ± 0.62 mol%. The species name Porphyromonas pogonae sp. nov. is proposed for these isolates with the type strain of PAGU 1787 T (=MI 10-1288 T = JCM 19732 T = ATCC BAA-2643 T ). [ABSTRACT FROM AUTHOR]

The article presents a study analyzing platelet-derived growth factor using a splinted full thickness dermal wound model in bearded dragons. Topics include the effect of topical becaplermin (BP), a platelet-derived growth factor on the rate of wound closure, comparison of BP-treated and saline-treated wounds in order to observe wound healing rate and need for histological analysis of experimentally created wounds to evaluate the effects of these treatments on reptile dermal wound healing.

Three adult central bearded dragons (Pogona vitticeps) originating from a commercial breeding facility presented with clinical signs, including anorexia, dehydration, white multifocal lesions on the dorsal aspect of the tongue, blepharospasm, and weight loss. In 1 of 3 lizards, a marked regenerative anemia was noted, and all 3 bearded dragons had erythrocytic intracytoplasmic inclusion bodies. Nine bearded dragons housed in contact also had identical, but fewer intraerythrocytic inclusions. Inclusion bodies examined by electron microscopy had particles consistent with iridoviruses. Attempts to culture the virus were unsuccessful; however, amplification and sequencing of regions of the viral DNA polymerase by polymerase chain reaction confirmed the presence of an iridovirus. One of the bearded dragons died, while the 2 others showing clinical signs were euthanized. The remaining 9 infected bearded dragons of the teaching colony were also euthanized. Postmortem examination revealed a moderate, multifocal, lymphoplasmacytic or mononuclear adenitis of the tongue in the 3 bearded dragons, and a lymphohistiocytic hepatitis with bacterial granulomas in 2 lizards. [ABSTRACT FROM PUBLISHER]

The coccidian parasite Choleoeimeria pogonae infests the biliary ducts and gallbladder of the central bearded dragon (Pogona vitticeps). Endogenous C. pogonae development occurs in the epithelium of the gallbladder and bile ducts, leading to significant tissue injury. To determine whether bile composition in the gallbladder was disrupted by the parasite, bile samples were collected from one normal and one C. pogonae–infected central bearded dragon. Bile acid species were identified and quantified with liquid chromatography and mass spectroscopy. Tauroallochoic acid was the predominant bile acid (82.2%) in the normal bearded dragon, whereas the deconjugated allocholic acid was the predominant bile acid (40.1%) in the bearded dragon with C. pogonae. Taurine conjugation inhibits calcium precipitation in bile and bile acid–mediated ductal epithelial cytotoxicity. The shift in bile acid content identified in the C. pogonae infected bearded dragon may contribute to cholelithiasis and mucosal damage. [ABSTRACT FROM AUTHOR]

Case report Juvenile inland bearded dragons ( Pogona vitticeps) from a breeding collection in south-east Queensland were presented at age 6-10 weeks with neurological signs, poor growth and occasional deaths. Histopathological examination revealed that six of eight lizards had multifocal non-suppurative hepatitis associated with 5-10 μm diameter, smudgy, basophilic, hyaline intranuclear inclusion bodies that marginated the nuclear chromatin. These histological lesions were considered consistent with adenoviral hepatitis. Infection with adenovirus was confirmed positive in one of the eight dragons by PCR for adenoviral DNA. DNA was extracted from formalin-fixed paraffin-embedded pooled tissues of the juvenile inland bearded dragons and tested using a nested- PCR protocol with primers specific for identification of adenovirus. Sequencing of the one PCR-positive dragon showed 95% nucleotide sequence alignment with agamid atadenovirus 1. Further investigation involved testing the breeding population, including the parents of the affected juveniles. Blood and cloacal samples were collected from the adult population, DNA was extracted and tested by PCR for adenovirus. There was a high percentage of positive results from the samples collected from the breeding population. Conclusion This is the first reported group outbreak of adenoviral disease in bearded dragons in Australia. [ABSTRACT FROM AUTHOR]

A 4.5-year-old female bearded dragon ( Pogona vitticeps) presented for periorbital swelling affecting the left eye. A well-organized, hypoechoic mass was noted ventral and medial to the globe on ocular ultrasound. The mass continued to grow despite antibiotic therapy, and an exenteration was performed. The mass was diagnosed via histopathology and immunohistochemical staining as a probable lacrimal gland carcinoma, although a Harderian gland origin could not definitively be ruled out. The tumor recurred following removal, and the lizard died 2 months postoperatively. [ABSTRACT FROM AUTHOR]

Abstract: Vitamin D deficiency can lead to several health problems collectively called metabolic bone disease (MBD). One commonly kept reptile species prone to develop MBD if managed incorrectly is the bearded dragon (Pogona vitticeps). This study aimed to determine the extent to which adult female bearded dragons fed a diet low in vitamin D can use stored vitamin D and its metabolites to maintain plasma 25(OH)D3 and 1,25(OH)2D3 concentrations after discontinuing UVb exposure. Blood samples of healthy adult female bearded dragons, exposed to UVb radiation for over 6months were collected (day 0) after which UVb exposure was discontinued for 83days and blood was collected. Blood plasma was analysed for concentrations of total Ca, total P, ionized Ca, uric acid, 25(OH)D3 and 1,25(OH)2D3. There was no significant change in plasma 25(OH)D3 and 1,25(OH)2D3 concentrations during the study. While total Ca and P in whole blood was found to significantly decrease over time (P<0.0088 and 0.0016, respectively), values were within the reference range. Plasma ionized Ca tended (P=0.0525) to decrease during the study. Adult female bearded dragons, previously exposed to UVb, are able to maintain blood vitamin D metabolite concentrations when UVb exposure is discontinued for a period of up to 83days. [Copyright &y& Elsevier]

Gonadectomy of pet lizards may be necessary to treat various medical conditions, and pro- phylactic surgery may prevent life-threatening reproductive-associated conditions. This study provides information relevant to the pre-surgical evaluation of bearded dragons (Pogona vitticeps). Blood samples collected from seven male and seven female inland bearded dragons prior to elective gonadectomy surgery, and again 12 days following surgery, were analyzed using a point-of-care blood gas analyzer (iStat) and a semiportable chemistry analyzer (Abaxis VetScan) to obtain plasma biochemistry and electrolyte con- centrations. Statistically significant differences were seen for packed cell volume and protein, calcium, and potassium concentrations when pre-surgical values were compared with post-surgical values. Four female lizards in the cohort died in the immediate post-operative period, and three of these animals had large, well-developed ovarian follicles. The ovaries of all surviving female lizards were characterized by small follicles consistent with inactivity. Minimal differences were seen in the biochemistry ranges for lizards that survived versus those that did not. None of the biochemical differences were of sufficient magnitude to be clinically important, but reproductive status of female bearded dragons should be considered prior to this invasive surgical procedure. [ABSTRACT FROM AUTHOR]

A central bearded dragon (Pogona vitticeps) presented with periorbital swelling and exophthalmos. A retrobulbar mass was detected, and enucleation with the mass was performed. Histologically, the mass was composed of a dense sheet and interlacing bundles of round to polygonal to short spindle-shaped cells with occasional bizarre mononuclear and multinucleated giant cells. Immunohistochemically, the neoplastic cells had various degrees of membranous and/or cytoplasmic granular reactivity to anti-ionized calcium-binding adapter molecule 1 and anti-CD204 antibodies. Ultrastructurally, the neoplastic cells had irregular nuclei and abundant cytoplasm with membrane-bound electron-dense lysosomes and endoplasmic reticula. These findings were consistent with a histiocytic sarcoma. The present study provided a detailed description of retrobulbar histiocytic sarcoma for the first time in a central bearded dragon.

The bearded dragon (Pogona vitticeps) is (perhaps) the most common pet lizard in the United States. The purpose of this review article is to provide a practical overview of the natural history, husbandry, nutrition, reproduction, physical examination method, diagnostic techniques, currently recognized diseases, and therapeutics found useful for the bearded dragon. Nutritional secondary hyperparathyroidism and trauma attributable to cage-mate aggression are common problems encountered in juvenile dragons. Intestinal impaction and renal and cardiac diseases are more commonly seen in adult dragons. Newly described malignancies such as periocular squamous cell carcinoma and gastric carcinoma have also been reported in juvenile and adult bearded dragons. [ABSTRACT FROM AUTHOR]

In May 2011, 22 cloacal swabs and plasma samples were collected from 22 bearded dragons (Pogona vitticeps) from a rescue center in Munich, Germany. All of the lizards swabbed were healthy throughout the observation period and did not show any clinical signs during the course of the study. The swabs were tested for the presence of ferlaviruses (Paramyxoviridae) and adenoviruses (AdVs) using reverse transcriptase polymerase chain reaction (RT-PCR) and PCR methods. Virus isolation attempts were carried out on two iguana heart cells. Plasma was tested for antibodies against several ferlavirus isolates using a hemagglutination inhibition (HI) test. A second round of testing was carried out on 27 animals four months later. Of all swabs tested in the first round, 11 (50%) were positive for ferlaviruses using an RT-PCR. Sequences of the PCR products of all detected ferlaviruses were 100% identical to corresponding sequences of isolate Pyth-GER01 that was originally isolated from a python. One swab (4.5%) was positive for an AdV, and the PCR product was 100% identical to Agamid AdV-1 (Acc. No. DQ077706). No virus was isolated from the cloacal swabs. The HI test revealed low titers of ≤8 against Pyth-Ger01 for all samples tested. Four months later, no ferlaviruses were detected in any of the samples tested by RT-PCR. However, four animals (14.8%) were found positive for an AdV. Sequence analyses of a portion of the DNA-dependent DNA polymersase gene revealed three new AdVs that were 99% similar to Agamid AdV-1 (Acc. No AY576678). Antibody titers of 16-32 against at least one ferlavirus were detected in six of the animals sampled four months later. This is the first report documenting the occurence of ferlavirus infection in bearded dragons. [ABSTRACT FROM AUTHOR]

An 8-yr-old male bearded dragon (Pogona vitticeps) was presented for evaluation of a mass involving the right eyelid. The mass was surgically removed in conjunction with enucleation of the right eye. Tissues were submitted for histopathology, which revealed that the eyelid mass was a squamous cell carcinoma (SCC). A review of the records from two separate zoological pathology laboratories identified a total of 12 reports of SCC in bearded dragons; this represented 6% of the neoplasms documented in bearded dragons from the two laboratories over a 10 yr period. Nine (75%) of the 12 SCCs were located in the eye- lids or periocular tissues; one (8.3%) was located on the rostral mandible; one (8.3%) was located adjacent to the vent; and one (8.3%) was on the proximal right rear leg. These findings suggest a predilection of SCCs in bearded dragons in proximity to a mucocutaneous junction (11/12, 9l.6%), particularly in the periocular tissues (9/12, 75%). [ABSTRACT FROM AUTHOR]

The article presents a case study of a 4.5-year-old male bearded dragon that was presented for anorexia, lethargy, and augmented mucoid salivation with upper respiratory chatters. It says that a clinical diagnosis of chronic monocytic leukemia was done, but the dragon become unresponsive and died within one hour 40-hours into the treatment. It adds that poor effects as a result of intravenous (i.v.) cytosine arabinoside therapy were unknown despite the reports that the drug causes renal failure.

Cryptosporidia are regularly detected during routine coprologic screenings of healthy bearded dragons (Pogona vitticeps). The objectives of this study were to histologically characterize infections by Cryptosporidium sp. in bearded dragons and to evaluate the effect of paromomycin treatment in bearded dragons infected by Cryptosporidium sp. Ten four-month-old bearded dragons were initially infected with an isolate of Cryptosporidium sp. that was acquired from a naturally infected adult bearded dragon. The infection was confirmed in both groups by coprologic examination. The infected animals were then divided into two groups: a treatment group and a control group. Oral treatment with paromomycin began seven weeks after infection in the treatment group using the following regimens: 100 mg/kg q 24 h for seven days; then twice a week for six weeks; and 360 mg/kg q 48 h during the final 10 days of the study. Cryptosporidia were only detected in the intestinal lumens in the non-treated lizards. None of the treated lizards showed evidence of cryptosporidia excretion on either coprologic or histopathological examination. This finding suggests that the treatment with paromomycin was effective. All bearded dragons from both groups remained fully asymptomatic. Nevertheless, because of the highly contagious nature of these parasites and the pathogenicity to species that may be housed in the vicinity of asymptomatic carriers, and because a possible pathogenic effect for immunocompromised bearded dragons cannot be ruled out, treatment of infected bearded dragons remains a recommended practice. [ABSTRACT FROM AUTHOR]

The article discusses a report on the isolation and preliminary identification of a reptile-associated Porphyromonas variant that represents a new species and describes a Porphyromonas-associated clinical infections in reptiles. The patients included an 8-year-old female bearded dragon, an adult, female central bearded dragon and an approximately 8-year old male central bearded dragon. It indicates that the unique Porphyromonas sp. is a significant, opportunistic bacterial pathogen in necrosuppurative diseases of central bearded dragons.

The haemoglobin protein, required for oxygen transportation in the body, is encoded by α- and β-globin genes that are arranged in clusters. The transpositional model for the evolution of distinct α-globin and β-globin clusters in amniotes is much simpler than the previously proposed whole genome duplication model. According to this model, all jawed vertebrates share one ancient region containing α- and β-globin genes and several flanking genes in the order MPG-C16orf35-(α-β)-GBY-LUC7L that has been conserved for more than 410 million years, whereas amniotes evolved a distinct β-globin cluster by insertion of a transposed β-globin gene from this ancient region into a cluster of olfactory receptors flanked by CCKBR and RRM1. It could not be determined whether this organisation is conserved in all amniotes because of the paucity of information from non-avian reptiles. To fill in this gap, we examined globin gene organisation in a squamate reptile, the Australian bearded dragon lizard, Pogona vitticeps (Agamidae). We report here that the α-globin cluster ( HBK, HBA) is flanked by C16orf35 and GBY and is located on a pair of microchromosomes, whereas the β-globin cluster is flanked by RRM1 on the 3′ end and is located on the long arm of chromosome 3. However, the CCKBR gene that flanks the β-globin cluster on the 5′ end in other amniotes is located on the short arm of chromosome 5 in P. vitticeps, indicating that a chromosomal break between the β-globin cluster and CCKBR occurred at least in the agamid lineage. Our data from a reptile species provide further evidence to support the transpositional model for the evolution of β-globin gene cluster in amniotes. [ABSTRACT FROM AUTHOR]