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Journal of Toxicology and Environmental... Jan 2024Bioactive compounds derived from secondary metabolism in animals have refined selectivity and potency for certain biological targets. The superfamily Dendrobatoidea is... (Review)
Review
Bioactive compounds derived from secondary metabolism in animals have refined selectivity and potency for certain biological targets. The superfamily Dendrobatoidea is adapted to the dietary sequestration and secretion of toxic alkaloids, which play a role in several biological activities, and thus serve as a potential source for pharmacological and biotechnological applications. This article constitutes a scoping review to understand the trends in experimental research involving bioactive alkaloids derived from Dendrobatoidea based upon scientometric approaches. Forty-eight (48) publications were found in 30 journals in the period of 60 years, between 1962 and 2022. More than 23 structural classes of alkaloids were cited, with 27.63% for batrachotoxins, 13.64% for pyridinics, with an emphasis on epibatidine, 16.36% for pumiliotoxins, and 11.82% for histrionicotoxins. These tests included (54.9%), (39.4%), and simulations (5.6%). Most compounds (54.8%) were isolated from skin extracts, whereas the remainder were obtained through molecular synthesis. Thirteen main biological activities were identified, including acetylcholinesterase inhibitors (27.59%), sodium channel inhibitors (12.07%), cardiac (12.07%), analgesic (8.62%), and neuromuscular effects (8.62%). The substances were cited as being of natural origin in the "Dendrobatidae" family, genus "," "," and seven species: , , , , , , and . To date, only a few biological activities have been experimentally tested; hence, further studies on the bioprospecting of animal compounds and ecological approaches are needed.
Topics: Animals; Venoms; Acetylcholinesterase; Anura; Batrachotoxins; Alkaloids
PubMed: 37889647
DOI: 10.1080/10937404.2023.2270408 -
The Journal of Animal Ecology Sep 2023Amphibians suffer from large-scale population declines globally, and emerging infectious diseases contribute heavily to these declines. Amphibian Perkinsea (Pr) is a...
Amphibians suffer from large-scale population declines globally, and emerging infectious diseases contribute heavily to these declines. Amphibian Perkinsea (Pr) is a worldwide anuran pathogen associated with mass mortality events, yet little is known about its epidemiological patterns, especially in comparison to the body of literature on amphibian chytridiomycosis and ranavirosis. Here, we establish Pr infection patterns in natural anuran populations and identify important covariates including climate, host attributes and co-infection with Ranavirus (Rv). We used quantitative (q)PCR to determine the presence and intensity of Pr and Rv across 1234 individuals sampled throughout central Florida in 2017-2019. We then implemented random forest ensemble learning models to predict infection with both pathogens based on physiological and environmental characteristics. Perkinsea infected 32% of all sampled anurans, and Pr prevalence was significantly elevated in Ranidae frogs, cooler months, metamorphosed individuals and frogs co-infected with Rv, while Pr intensity was significantly higher in ranid frogs and individuals collected dead. Ranavirus prevalence was 17% overall and was significantly higher in Ranidae frogs, metamorphosed individuals, locations with higher average temperatures, and individuals co-infected with Pr. Perkinsea prevalence was significantly higher than Rv prevalence across months, regions, life stages and species. Among locations, Pr prevalence was negatively associated with crayfish prevalence and positively associated with relative abundance of microhylids, but Rv prevalence did not associate with any tested co-variates. Co-infections were significantly more common than single infections for both pathogens, and we propose that Pr infections may propel Rv infections because seasonal Rv infection peaks followed Pr infection peaks and random forest models found Pr intensity was a leading factor explaining Rv infections. Our study elucidates epidemiological patterns of Pr in Florida and suggests that Pr may be under-recognized as a cause of anuran declines, especially in the context of pathogen co-infection.
Topics: Animals; Ranavirus; Coinfection; Florida; Ranidae; Climate
PubMed: 37409362
DOI: 10.1111/1365-2656.13977 -
Journal of Anatomy Sep 2023Frogs exhibit complex anatomical features of the pelvis, limbs and spine, long assumed to represent specialisations for jumping. Yet frogs employ a wide range of...
Frogs exhibit complex anatomical features of the pelvis, limbs and spine, long assumed to represent specialisations for jumping. Yet frogs employ a wide range of locomotor modes, with several taxa featuring primary locomotor modes other than jumping. Using a combination of techniques (CT imaging and 3D visualization, morphometrics, phylogenetic mapping), this study aims to determine the link between skeletal anatomy and locomotor style, habitat type and phylogenetic history, shedding new light on how functional demands impact morphology. Body and limb measurements for 164 taxa from all the recognised anuran families are extracted from digitally segmented CT scans of whole frog skeletons and analysed using various statistical techniques. We find that the expansion of the sacral diapophyses is the most important variable for predicting locomotor mode, which was more closely correlated with frog morphology than either habitat type or phylogenetic relationships. Predictive analyses suggest that skeletal morphology is a useful indicator of jumping but less so for other locomotor modes, suggesting that there is a wide range of anatomical solutions to performing locomotor styles such as swimming, burrowing or walking.
Topics: Humans; Animals; Phylogeny; Biological Evolution; Locomotion; Anura; Swimming
PubMed: 37203401
DOI: 10.1111/joa.13886 -
International Journal of Molecular... Sep 2023Pandemic and epidemic outbreaks of respiratory viruses are a challenge for public health and social care system worldwide, leading to high mortality and morbidity among...
Pandemic and epidemic outbreaks of respiratory viruses are a challenge for public health and social care system worldwide, leading to high mortality and morbidity among the human populations. In light of the limited efficacy of current vaccines and antiviral drugs against respiratory viral infections and the emergence and re-emergence of new viruses, novel broad-spectrum antiviral drugs are needed for the prevention and treatment of these infections. Antimicrobial peptides with an antiviral effect, also known as AVPs, have already been reported as potent inhibitors of viral infections by affecting different stages of the virus lifecycle. In the present study, we analyzed the activity of the AVP Hylin-a1, secreted by the frog , against a wide range of respiratory viruses, including the coronaviruses HCoV-229E and SARS-CoV-2, measles virus, human parainfluenza virus type 3, and influenza virus H1N1. We report a significant inhibitory effect on infectivity in all the enveloped viruses, whereas there was a lack of activity against the naked coxsackievirus B3. Considering the enormous therapeutic potential of Hylin-a1, further experiments are required to elucidate its mechanism of action and to increase its stability by modifying the native sequence.
Topics: Humans; Animals; Influenza A Virus, H1N1 Subtype; COVID-19; SARS-CoV-2; Antiviral Agents; Anura; Coronavirus 229E, Human
PubMed: 37762191
DOI: 10.3390/ijms241813888 -
The Journal of Experimental Biology Dec 2023The physical properties of the environment impose strong selection on organisms and their form-function relationships. In water and on land, selective pressures differ,...
The physical properties of the environment impose strong selection on organisms and their form-function relationships. In water and on land, selective pressures differ, with water being more viscous and denser than air, and gravity being the most important external force on land for relatively large animals such as vertebrates. These different properties of the environment could drive variation in the design and mechanics of the locomotor system of organisms. Animals that use multiple environments can consequently exhibit locomotion conflicts between the demands imposed by the media, leading to potential trade-offs. Here, we tested for the presence of such locomotor trade-offs depending on the environment (water or land) in a largely aquatic frog, Xenopus laevis. We focused on terrestrial and aquatic exertion capacity (time and distance swum or jumped until exhaustion) and aquatic and terrestrial burst capacity (maximal instantaneous swimming velocity and maximal force jump) given the ecological relevance of these traits. We tested these performance traits for trade-offs, depending on environments (water versus air) and locomotor modes (i.e. exertion and burst performance). Finally, we assessed the contribution of morphological traits to each performance trait. Our data show no trade-offs between the performance traits and between the environments, suggesting that X. laevis is equally good at swimming and jumping thanks to the same underlying morphological specialisations. We did observe, however, that morphological predictors differed depending on the environment, with variation in head shape and forelimb length being good predictors for aquatic locomotion and variation in hindlimb and forelimb segments predicting variation in jumping performance on land.
Topics: Animals; Xenopus laevis; Locomotion; Swimming; Hindlimb; Water
PubMed: 37990942
DOI: 10.1242/jeb.246545 -
Philosophical Transactions of the Royal... Jul 2023Macrophage (M)-lineage cells are integral to the immune defences of all vertebrates, including amphibians. Across vertebrates, M differentiation and functionality depend...
Macrophage (M)-lineage cells are integral to the immune defences of all vertebrates, including amphibians. Across vertebrates, M differentiation and functionality depend on activation of the colony stimulating factor-1 (CSF1) receptor by CSF1 and interluekin-34 (IL34) cytokines. Our findings to date indicate that amphibian () Ms differentiated with CSF1 and IL34 are morphologically, transcriptionally and functionally distinct. Notably, mammalian Ms share common progenitor population(s) with dendritic cells (DCs), which rely on fms-like tyrosine kinase 3 ligand (FLT3L) for differentiation while IL34-Ms exhibit many features attributed to mammalian DCs. Presently, we compared CSF1- and IL34-Ms with FLT3L-derived DCs. Our transcriptional and functional analyses indicated that indeed the frog IL34-Ms and FLT3L-DCs possessed many commonalities over CSF1-Ms, including transcriptional profiles and functional capacities. Compared to CSF1-Ms, the IL34-Ms and FLT3L-DCs possess greater surface major histocompatibility complex (MHC) class I, but not MHC class II expression, were better at eliciting mixed leucocyte responses and generating re-exposure immune responses against . Further analyses of non-mammalian myelopoiesis akin to those described here, will grant unique perspectives into the evolutionarily retained and diverged pathways of M and DC functional differentiation. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
Topics: Animals; Xenopus laevis; Myeloid Cells; Anura; Macrophages; Leukocytes; Mammals
PubMed: 37305910
DOI: 10.1098/rstb.2022.0124 -
Journal of Experimental Zoology. Part... Dec 2023Freeze tolerant animals survive the winter by tolerating the freezing and thawing of up to 70% of body water and the respective cessation and resumption of essential...
Freeze tolerant animals survive the winter by tolerating the freezing and thawing of up to 70% of body water and the respective cessation and resumption of essential functions including circulation and respiration during each freeze-thaw cycle. Cope's gray treefrog Dryophytes chrysoscelis is a freeze tolerant anuran that uses a system of cryoprotectants to prevent intracellular freezing and mitigate osmotic stress during freezing and thawing episodes. Morphological features were documented in D. chrysoscelis using a repeated freeze-thaw protocol. Dorsal skin in frozen frogs was distinctly blue and green before reverting to brown during thawing. The dorsal color change in frozen frogs does not function similarly to other known color change events in amphibians. The return to brown skin color in thawing animals coincides with recovery of vital functions in freeze tolerant frogs, suggesting that dorsal color change is an indicator of postfreeze recovery in D. chrysoscelis. We also provide evidence of "freeze resistance" in D. chrysoscelis. Two individuals did not freeze following three successive bouts of ice inoculation at -2.5°C and maintained brown dorsal color despite ice crystallization on the dorsum and contact with frozen substrate. Both frogs had similar plasma osmolality, circulating cryoprotectants, and incidence of cryoinjury compared to frogs that were frozen and thawed once or three times. Freeze resistance may be explained by physical changes in the skin including lipid accumulation and dehydration. This integrative study presents novel attributes of organismal freeze tolerance in D. chrysoscelis.
Topics: Humans; Animals; Freezing; Ice; Acclimatization; Anura; Cryoprotective Agents
PubMed: 37661700
DOI: 10.1002/jez.2753 -
Journal of Comparative Physiology. B,... Oct 2023Frogs evolved terrestrial development multiple times, necessitating mechanisms to avoid ammonia toxicity at early stages. Urea synthesis from ammonia is a key adaptation...
Frogs evolved terrestrial development multiple times, necessitating mechanisms to avoid ammonia toxicity at early stages. Urea synthesis from ammonia is a key adaptation that reduces water dependence after metamorphosis. We tested for early expression and plasticity of enzymatic mechanisms of ammonia detoxification in three terrestrial-breeding frogs: foam-nest-dwelling larvae of Leptodactylus fragilis (Lf) and arboreal embryos of Hyalinobatrachium fleischmanni (Hf) and Agalychnis callidryas (Ac). Activity of two ornithine-urea cycle (OUC) enzymes, arginase and CPSase, and levels of their products urea and CP in tissues were high in Lf regardless of nest hydration, but reduced in experimental low- vs. high-ammonia environments. High OUC activity in wet and dry nests, comparable to that under experimental high ammonia, suggests terrestrial Lf larvae maintain high capacity for urea excretion regardless of their immediate risk of ammonia toxicity. This may aid survival through unpredictably long waiting periods before rain enables their transition to water. Moderate levels of urea and CP were present in Hf and Ac tissues and enzymatic activities were lower than in Lf. In both species, embryos in drying clutches can hatch and enter the water early, behaviorally avoiding ammonia toxicity. Moreover, glutamine synthetase was active in early stages of all three species, condensing ammonia and glutamate to glutamine as another mechanism of detoxification. Enzyme activity appeared highest in Lf, although substrate and product levels were higher in Ac and Lf. Our results reveal that multiple biochemical mechanisms of ammonia detoxification occur in early life stages of anuran lineages that evolved terrestrial development.
Topics: Animals; Ammonia; Glutamate-Ammonia Ligase; Larva; Urea; Water; Anura; Liver
PubMed: 37639061
DOI: 10.1007/s00360-023-01506-4 -
The EMBO Journal Jun 2024Nuclear pore complex (NPC) biogenesis is a still enigmatic example of protein self-assembly. We now introduce several cross-reacting anti-Nup nanobodies for imaging...
Nuclear pore complex (NPC) biogenesis is a still enigmatic example of protein self-assembly. We now introduce several cross-reacting anti-Nup nanobodies for imaging intact nuclear pore complexes from frog to human. We also report a simplified assay that directly tracks postmitotic NPC assembly with added fluorophore-labeled anti-Nup nanobodies. During interphase, NPCs are inserted into a pre-existing nuclear envelope. Monitoring this process is challenging because newly assembled NPCs are indistinguishable from pre-existing ones. We overcame this problem by inserting Xenopus-derived NPCs into human nuclear envelopes and using frog-specific anti-Nup nanobodies for detection. We further asked whether anti-Nup nanobodies could serve as NPC assembly inhibitors. Using a selection strategy against conserved epitopes, we obtained anti-Nup93, Nup98, and Nup155 nanobodies that block Nup-Nup interfaces and arrest NPC assembly. We solved structures of nanobody-target complexes and identified roles for the Nup93 α-solenoid domain in recruiting Nup358 and the Nup214·88·62 complex, as well as for Nup155 and the Nup98 autoproteolytic domain in NPC scaffold assembly. The latter suggests a checkpoint linking pore formation to the assembly of the Nup98-dominated permeability barrier.
Topics: Nuclear Pore Complex Proteins; Nuclear Pore; Humans; Single-Domain Antibodies; Animals; Xenopus; Xenopus laevis; HeLa Cells
PubMed: 38649536
DOI: 10.1038/s44318-024-00081-w -
Animal Cognition Nov 2023The ability to perceive group size and discriminate the ontogeny of conspecifics would play a crucial role in the grouping behavior of animals. However, the relative...
The ability to perceive group size and discriminate the ontogeny of conspecifics would play a crucial role in the grouping behavior of animals. However, the relative importance of numerical quantity and size-assortative preferences in shaping grouping rules remains poorly understood. In this study, I examined the responses of Miyako toad (Bufo gargarizans miyakonis) tadpoles to number quantity and size discrimination by choice tests at different ontogenetic stages (small, medium, and large). The results revealed that small-sized tadpoles in early developmental stages significantly preferred larger numbers (4) compared to smaller ones (1). However, this preference was not observed in later developmental stages (medium and large). And interestingly, when there was no quantity bias, size discrimination was not observed in tadpoles, irrespective of their ontogeny. These findings suggest that Miyako toad tadpoles discern quantity, i.e., the number of conspecifics, but exhibit ontogeny-dependent utilization of this ability. Understanding the interplay between numerical quantity and size-assortative preferences in grouping behavior will provide esteemed insights into the adaptive value of number sense in vertebrates and shed light on evolutionary processes.
Topics: Animals; Larva; Behavior, Animal; Bufonidae
PubMed: 37668885
DOI: 10.1007/s10071-023-01823-9