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Background The oral microbiome comprises distinct microbial communities that colonize diverse ecological niches across the oral cavity, the composition of which are influenced by nutrient and substrate availability, host genetics, diet, behavior, age, and other diverse host and environmental factors. Unlike other densely populated human-associated microbial ecosystems (e.g., gut, urogenital), the oral microbiome is regularly and directly exposed to the external environment and is therefore likely less stable over time. Cross sectional studies of the oral microbiome capture a glimpse of this temporal dynamism, yet a full appreciation of the relative stability, robusticity, and spatial structure of the oral environment is necessary to understand the role of microbial communities in promoting health or disease. Results Here we investigate the spatial and temporal stability of the oral microbiome over three sampling time points in the context of HIV infection and exposure. Individual teeth were sampled from a cohort of 565 Nigerian children with varying levels of tooth decay severity (i.e., caries disease). We collected 1,960 supragingival plaque samples and characterized the oral microbiome using a metataxonomic approach targeting an approximately 478 bp region of the bacterial rpo C gene. We found that both infection and exposure to HIV have significant effects on the stability of the supragingival plaque microbiome at both the spatial and temporal scale. Specifically, we detect (1) significantly lower taxonomic turnover of the oral community among exposed and infected children compared to unexposed children, (2) we find that HIV infection homogenizes the oral community across the anterior and posterior dentition, and (3) that impaired immunity (i.e., low CD4 count) and low taxonomic turnover over time in children living with HIV is associated with higher frequency of cariogenic taxa including Streptococcus mutans . Conclusions Our results document substantial community fluctuations over time in children unexposed to HIV independent of oral health status. This suggests that the oral community, under typical conditions, rapidly adapts to environmental perturbations to maintain homeostasis and that long-term taxonomic rigidity is a signal of community dysfunction, potentially leading to a higher incidence of oral disease including caries.
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More than a century ago, Charles Darwin hypothesized that the empathy-like phenotype is a phylogenetically widespread phenomenon. This idea remains contentious, due to the challenges of empirically examining emotions, and few investigations among non-mammalian vertebrates. We provide support for Darwin's hypothesis by discovering partial evidence for the most ancestral form of empathy, emotional contagion (i.e. matching another individual's emotional state), in the pair bonding mimetic poison frog, Ranitomeya imitator. We found that male corticosterone, a physiological biomarker of stress, positively correlates with female partners in experimental and semi-natural conditions. This does not appear to coincide with behavioural state-matching. However, it is specific to female partners relative to familiar female non-partners, and is independent of effects that commonly confound studies on emotional contagion. Furthermore, this physiological state-matching is irrespective of partnership longevity or lifetime reproductive output. These results physiologically indicate socially selective emotional contagion in a monogamous amphibian, and paradigms that elicit coinciding neural and behavioural indicators and morphogenic co-variation are needed for further corroboration. Further studies on ancestral forms of empathy in non-mammalian vertebrates are warranted.
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Introduction Although effective, conventional excisional haemorrhoidectomy (CEH) may be associated with significant postoperative pain. Novel techniques such as transanal haemorrhoidal dearterialization (THD) are suggested to reduce pain, but may result in higher recurrence rates. We aimed to compare short and long-term outcomes of CEH and THD in the present meta-analysis. Methods A PRISMA-compliant meta-analysis was performed, searching PubMed, EMBASE and CENTRAL databases for randomized controlled trials (RCTs) from 1995 until December 2022. The primary objective was recurrence. Secondary objectives included complication rates, length of stay (LOS), operative time and time to return to baseline. Random-effects models were used to calculate pooled effect size estimates. Subgroup analysis was also performed. Results 6 RCTs encompassing 465 patients were captured. There were 142 (59%) males in the CEH group and 129 (54%) in the THD group.. On random effects analysis, THD had a higher recurrence rate (OR = 2.76, 95% CI = 1.03 to 7.38, p = 0.04) albeit a shorter return to baseline comparative to CEH (MD = -14.05 days, 95% CI = -20.38 to -7.72, p < 0.0001). There were no differences in bleeding (p = 0.12), urinary retention (p = 0.97), incontinence (p = 0.41), anal stenosis (p = 0.19), thrombosed residual haemorrhoids (p = 0.16), operating time (p = 0.19) or LOS (p = 0.22). Results remained similar on subgroup analysis. Conclusions CEH is associated with lower recurrence rates and no difference in complication rate to THD, although patients take longer to return to baseline function postoperatively.
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The behavioral, sensory, and neural bases of vertebrate navigation are primarily described in mammals and birds. However, we know much less about navigational abilities and mechanisms of vertebrates that move on smaller scales, such as amphibians. To address this knowledge gap, we conducted an extensive field study on navigation in the cane toad, Rhinella marina. First, we performed a translocation experiment to describe how invasive toads in Hawai'i navigate home following displacements of up to one kilometer. Next, we tested the effect of olfactory and magnetosensory manipulations on homing, as these senses are most commonly associated with amphibian navigation. We found that neither ablation alone prevents homing, suggesting that toad navigation is multimodal. Finally, we tested the hypothesis that the medial pallium, the amphibian homolog to the hippocampus, is involved in homing. By comparing neural activity across homing and non-homing toads, we found evidence supporting the involvement of the medial pallium, lateral pallium, and septum in navigation, suggesting a conservation of neural structures supporting navigation across vertebrates. Our study lays the foundation to understand the behavioral, sensory, and neural bases of navigation in amphibians and to further characterize the evolution of behavior and neural structures in vertebrates.
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The ways in which animals sense the world changes throughout development. For example, young of many species have limited visual capabilities, but still make social decisions, likely based on information gathered through other sensory modalities. Poison frog tadpoles display complex social behaviors that have been suggested to rely on vision despite a century of research indicating tadpoles have poorly-developed visual systems relative to adults. Alternatively, other sensory modalities, such as the lateral line system, are functional at hatching in frogs and may guide social decisions while other sensory systems mature. Here, we examined development of the mechanosensory lateral line and visual systems in tadpoles of the mimic poison frog (Ranitomeya imitator) that use vibrational begging displays to stimulate egg feeding from their mothers. We found that tadpoles hatch with a fully developed lateral line system. While begging behavior increases with development, ablating the lateral line system inhibited begging in pre-metamorphic tadpoles, but not in metamorphic tadpoles. We also found that the increase in begging and decrease in reliance on the lateral line co-occurs with increased retinal neural activity and gene expression associated with eye development. Using the neural tracer neurobiotin, we found that axonal innervations from the eye to the brain proliferate during metamorphosis, with few retinotectal connections in recently-hatched tadpoles. We then tested visual function in a phototaxis assay and found tadpoles prefer darker environments. The strength of this preference increased with developmental stage, but eyes were not required for this behavior, possibly indicating a role for the pineal gland. Together, these data suggest that tadpoles rely on different sensory modalities for social interactions across development and that the development of sensory systems in socially complex poison frog tadpoles is similar to that of other frog species.
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Larva , Animais , Larva/fisiologia , Metamorfose Biológica/fisiologia , Sistema da Linha Lateral/fisiologia , Comunicação Animal , Ranidae/fisiologia , Visão Ocular/fisiologia , Retina/fisiologiaRESUMO
Water plays a notable role in the ecology of most terrestrial organisms due to the risks associated with water loss. Specifically, water loss in terrestrial animals happens through evaporation across respiratory tissues or epidermis. Amphibians are ideal systems for studying how abiotic factors impact water loss since their bodies often respond quickly to environmental changes. While the effect of temperature on water loss is well known across many taxa, we are still learning how temperature in combination with humidity or water availability affects water loss. Here, we tested how standing water sources (availability) and temperature (26 and 36°C) together affect water loss in anuran amphibians using a Bayesian framework. We also present a conceptual model for considering how water availability and temperature may interact, resulting in body mass changes. After accounting for phylogenetic and time autocorrelation, we determined how different variables (water loss and uptake rates, temperature, and body size) affect body mass in three species of tropical frogs (Rhinella marina, Phyllobates terribilis, and Xenopus tropicalis). We found that all variables impacted body mass changes with greater similarities between P. terribilis and X. tropicalis, but only temperature showed a notable effect in P. terribilis. Furthermore, we describe how the behavior of P. terribilis might affect its water budget. This study shows how organisms might manage water budgets across different environments and is important for developing our models of evaporative water loss and species distributions.
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Genome size varies greatly across the tree of life and transposable elements are an important contributor to this variation. Among vertebrates, amphibians display the greatest variation in genome size, making them ideal models to explore the causes and consequences of genome size variation. However, high-quality genome assemblies for amphibians have, until recently, been rare. Here, we generate a high-quality genome assembly for the dyeing poison frog, Dendrobates tinctorius. We compare this assembly to publicly available frog genomes and find evidence for both large-scale conserved synteny and widespread rearrangements between frog lineages. Comparing conserved orthologs annotated in these genomes revealed a strong correlation between genome size and gene size. To explore the cause of gene-size variation, we quantified the location of transposable elements relative to gene features and find that the accumulation of transposable elements in introns has played an important role in the evolution of gene size in D. tinctorius, while estimates of insertion times suggest that many insertion events are recent and species-specific. Finally, we carry out population-scale mobile-element sequencing and show that the diversity and abundance of transposable elements in poison frog genomes can complicate genotyping from repetitive element sequence anchors. Our results show that transposable elements have clearly played an important role in the evolution of large genome size in D. tinctorius. Future studies are needed to fully understand the dynamics of transposable element evolution and to optimize primer or bait design for cost-effective population-level genotyping in species with large, repetitive genomes.
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Anuros , Elementos de DNA Transponíveis , Evolução Molecular , Tamanho do Genoma , Genoma , Animais , Anuros/genética , Rãs VenenosasRESUMO
AIM: Some patients with inflammatory bowel disease (IBD) require subtotal colectomy (STC) with ileostomy. The recent literature reports a significant number of patients who do not undergo subsequent surgery and are resigned to living with a definitive stoma. The aim of this work was to analyse the rate of definitive stoma and the cumulative incidence of secondary reconstructive surgery after STC for IBD in a large national cohort study. METHOD: A national retrospective study (2013-2021) was conducted on prospectively collected data from the French Medical Information System Database (PMSI). All patients undergoing STC in France were included. The association between definitive stoma and potential risk factors was studied using univariate and multivariate analyses. RESULTS: A total of 1860 patients were included (age 45 ± 9 years; median follow-up 30 months). Of these, 77% (n = 1442) presented with ulcerative colitis. Mortality and morbidity at 90 days after STC were 5% (n = 100) and 47% (n = 868), respectively. Reconstructive surgery was identified in 1255 patients (67%) at a mean interval of 7 months from STC. Seveny-four per cent (n = 932) underwent a completion proctectomy with ileal pouch anal anastomosis and 26% (n = 323) an ileorectal anastomosis. Six hundred and five (33%) patients with a definitive stoma had an abdominoperineal resection (n = 114; 19%) or did not have any further surgical procedure (n = 491; 81%). Independent risk factors for definitive stoma identified in multivariate analysis were older age, Crohn's disease, colorectal neoplasia, postoperative complication after STC, laparotomy and a low-volume hospital. CONCLUSION: We found that 33% of patients undergoing STC with ileostomy for IBD had definitive stoma. Modifiable risk factors for definitive stoma were laparotomy and a low-volume hospital.
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Colectomia , Ileostomia , Humanos , Pessoa de Meia-Idade , Feminino , Masculino , França/epidemiologia , Colectomia/métodos , Colectomia/estatística & dados numéricos , Colectomia/efeitos adversos , Ileostomia/estatística & dados numéricos , Ileostomia/efeitos adversos , Estudos Retrospectivos , Adulto , Fatores de Risco , Doenças Inflamatórias Intestinais/cirurgia , Estomas Cirúrgicos/estatística & dados numéricos , Estomas Cirúrgicos/efeitos adversos , Reoperação/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Colite Ulcerativa/cirurgia , Doença de Crohn/cirurgiaRESUMO
Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used Caenorhabditis elegans chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that C. elegans avoid extracts of the pavement ant ( Tetramorium immigrans ) and either osm-9 or tax-4 ion channels are required for this response. These experiments were conducted in an undergraduate laboratory course, demonstrating that new insights into interspecies interactions can be generated through genuine research experiences in a classroom setting.
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BACKGROUND: Although numerous treatments exist for the management of rectovaginal fistula, none has demonstrated its superiority. The role of diverting stoma remains controversial. A few series include Martius flap in the armamentarium. OBJECTIVE: Determine the role of gracilis muscle interposition and Martius flap in the surgical management of rectovaginal fistula. DESIGN: Retrospective cohort study of a pooled prospectively maintained database from 3 centers. PATIENTS: All consecutive eligible patients with rectovaginal fistula undergoing Martius flap and gracilis muscle interposition were included from 2001 to 2022. MAIN OUTCOME MEASURES: Success was defined by the absence of stoma and rectovaginal fistula. RESULTS: Sixty-two patients were included with 55 Martius flap and 24 gracilis muscle interposition performed after failures of 164 initial procedures. Total length of stay was longer for gracilis muscle interposition by 2 days ( p = 0.01) without a significant difference in severe morbidity (20% vs 12%, p = 0.53). Twenty-seven percent of the Martius flap interpositions were performed without a stoma, which did not have an impact on overall morbidity ( p = 0.763). Per patient immediate success rates were not significantly different between groups (35% vs 31%, p > 0.99). The success of gracilis muscle interposition after the failure of the Martius flap was not significantly different from an initial gracilis muscle interposition ( p > 0.99). After simple perineal procedures, the immediate success rate rose to 49.4% (49% vs 50%, p > 0.99). After a median follow-up of 23 months, no significant difference was detected in success rate between the 2 procedures (69% vs 69%, p > 0.99). Smoking was the only negative predictive factor ( p = 0.02). LIMITATIONS: By its retrospective nature, this study is limited in its comparison. CONCLUSIONS: This novel comparison between Martius flap and gracilis muscle interposition suggests that Martius flap presents several advantages, including shorter length of stay, similar morbidity, and similar success rate. Proximal diversion via a stoma for Martius flap does not appear mandatory. Gracilis muscle interposition could be reserved as a salvage procedure after Martius flap failure. See Video Abstract . FSTULA RECTOVAGINAL CUL ES EL ROL DEL COLGAJO DE MARTIUS Y LA INTERPOSICIN DEL MSCULO GRACILIS EN LA ESTRATEGIA TERAPUTICA: ANTECEDENTES:Si bien existen numerosos tratamientos para el manejo de la fistula rectovaginal, ninguno ha demostrado su superioridad. El papel del estoma de derivación sigue siendo controvertido. Pocas series incluyen colgajo de Martius en el armamento.OBJETIVO:Determinar el rol de la interposición del músculo gracilis y del colgajo de Martius, en el manejo quirúrgico de la fístula rectovaginal.DISEÑO:Estudio de cohorte retrospectivo de una base de datos mantenida prospectivamente en 3 centros.AJUSTES/PACIENTES:Se incluyeron todos los pacientes elegibles consecutivos con fistula rectovaginal sometidos a colgajo de Martius y la interposición del músculo gracilis desde 2001 hasta 2022.RESULTADOS PRINCIPALES:El éxito se definió por la ausencia de estoma y fistula rectovaginal.RESULTADOS:Se incluyeron 62 pacientes con 55 colgajo de Martius y 24 con interposición del músculo gracilis realizados después de fracasos de 164 procedimientos iniciales. La duración total de la estancia hospitalaria fue dos días más larga para la interposición del músculo gracilis ( p = 0,01) sin una diferencia significativa en la morbilidad grave (20% frente a 12%, p = 0,53). El 27% de los colgajos de Martius se realizaron sin estoma, sin impacto en la morbilidad global ( p = 0,763). Las tasas de éxito inmediato por paciente no fueron significativamente diferentes entre los grupos (35% vs. 31%, p = 1,0). El éxito de la interposición del músculo gracilis después del fracaso del colgajo de Martius no fue significativamente diferente de una interposición del músculo gracilis inicial (p = 1,0). La tasa de éxito inmediato aumentó al 49,4% (49% frente a 50%, p = 1,0) después de procedimientos perineales simples. Después de una mediana de seguimiento de 23 meses, no se detectaron diferencias significativas en la tasa de éxito entre los dos procedimientos (69 % frente a 69 %, p = 1,0). El tabaquismo fue el único factor predictivo negativo ( p = 0,02).LIMITACIONES:Por su naturaleza retrospectiva, este estudio tiene limitaciones en su comparación.CONCLUSIÓN:Esta novedosa comparación entre colgajo de Martius y la interposición del músculo gracilis sugiere que el colgajo de Martius presenta varias ventajas, incluida una estancia prolongada más corta, una morbilidad similar y un éxito. La derivación proximal a través de un estoma para el colgajo de Martius no parece obligatoria. La interposición del músculo gracilis podría reservarse como procedimiento de rescate después de una falla de colgajo de Martius. (Traducción-Dr. Aurian Garcia Gonzalez ).
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Músculo Grácil , Fístula Retovaginal , Retalhos Cirúrgicos , Humanos , Músculo Grácil/transplante , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Fístula Retovaginal/cirurgia , Adulto , Músculos Superficiais do Dorso/transplante , Resultado do Tratamento , Idoso , Tempo de Internação/estatística & dados numéricos , Procedimentos de Cirurgia Plástica/métodos , Estomas Cirúrgicos/efeitos adversosRESUMO
AIM: Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer facilitates tumour downstaging and complete pathological response (pCR). The goal of neoadjuvant systemic chemotherapy (total neoadjuvant chemotherapy, TNT) is to further improve local and systemic control. While some patients forgo surgery, total mesorectal excision (TME) remains the standard of care. While TNT appears to be noninferior to nCRT with respect to short-term oncological outcomes few data exist on perioperative outcomes. Perioperative morbidity including anastomotic leaks is associated with a negative effect on oncological outcomes, probably due to a delay in proceeding to adjuvant therapy. Thus, we aimed to compare conversion rates, rates of sphincter-preserving surgery and anastomosis formation rates in patients undergoing rectal resection after either TNT or standard nCRT. METHODS: An institutional colorectal oncology database was searched from January 2018 to July 2023. Inclusion criteria comprised patients with histologically confirmed rectal cancer who had undergone neoadjuvant therapy and TME. Exclusion criteria comprised patients with a noncolorectal primary, those operated on emergently or who had local excision only. Outcomes evaluated included rates of conversion to open, sphincter-preserving surgery, anastomosis formation and anastomotic leak. RESULTS: A total of 119 patients were eligible for inclusion (60 with standard nCRT, 59 with TNT). There were no differences in rates of sphincter preservation or primary anastomosis formation between the groups. However, a significant increase in conversion to open (p = 0.03) and anastomotic leak (p = 0.03) was observed in the TNT cohort. CONCLUSION: In this series TNT appears to be associated with higher rates of conversion to open surgery and higher anastomotic leak rates. While larger studies will be required to confirm these findings, these factors should be considered alongside oncological benefits when selecting treatment strategies.
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Terapia Neoadjuvante , Protectomia , Neoplasias Retais , Humanos , Neoplasias Retais/terapia , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Terapia Neoadjuvante/métodos , Masculino , Pessoa de Meia-Idade , Feminino , Idoso , Resultado do Tratamento , Protectomia/métodos , Fístula Anastomótica/etiologia , Estudos Retrospectivos , Anastomose Cirúrgica , Conversão para Cirurgia Aberta/estatística & dados numéricos , Quimiorradioterapia Adjuvante/métodos , Tratamentos com Preservação do Órgão/métodos , Estadiamento de Neoplasias , Reto/cirurgia , Reto/patologia , AdultoRESUMO
Arginine catabolism by the bacterial arginine deiminase system (ADS) has anticariogenic properties through the production of ammonia, which modulates the pH of the oral environment. Given the potential protective capacity of the ADS pathway, the exploitation of ADS-competent oral microbes through pre- or probiotic applications is a promising therapeutic target to prevent tooth decay. To date, most investigations of the ADS in the oral cavity and its relation to caries have focused on indirect measures of activity or on specific bacterial groups, yet the pervasiveness and rate of expression of the ADS operon in diverse mixed microbial communities in oral health and disease remain an open question. Here, we use a multivariate approach, combining ultra-deep metatranscriptomic sequencing with paired metataxonomic and in vitro citrulline quantification to characterize the microbial community and ADS operon expression in healthy and late-stage cavitated teeth. While ADS activity is higher in healthy teeth, we identify multiple bacterial lineages with upregulated ADS activity on cavitated teeth that are distinct from those found on healthy teeth using both reference-based mapping and de novo assembly methods. Our dual metataxonomic and metatranscriptomic approach demonstrates the importance of species abundance for gene expression data interpretation and that patterns of differential expression can be skewed by low-abundance groups. Finally, we identify several potential candidate probiotic bacterial lineages within species that may be useful therapeutic targets for the prevention of tooth decay and propose that the development of a strain-specific, mixed-microbial probiotic may be a beneficial approach given the heterogeneity of taxa identified here across health groups. IMPORTANCE: Tooth decay is the most common preventable chronic disease, affecting more than two billion people globally. The development of caries on teeth is primarily a consequence of acid production by cariogenic bacteria that inhabit the plaque microbiome. Other bacterial strains in the oral cavity may suppress or prevent tooth decay by producing ammonia as a byproduct of the arginine deiminase metabolic pathway, increasing the pH of the plaque biofilm. While the benefits of arginine metabolism on oral health have been extensively documented in specific bacterial groups, the prevalence and consistency of arginine deiminase system (ADS) activity among oral bacteria in a community context remain an open question. In the current study, we use a multi-omics approach to document the pervasiveness of the expression of the ADS operon in both health and disease to better understand the conditions in which ADS activity may prevent tooth decay.
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Cárie Dentária , Microbiota , Humanos , Amônia/metabolismo , Hidrolases/genética , Hidrolases/metabolismo , Microbiota/genética , Arginina/metabolismoRESUMO
Shifts in microbiome community composition can have large effects on host health. It is therefore important to understand how perturbations, like those caused by the introduction of exogenous chemicals, modulate microbiome community composition. In poison frogs within the family Dendrobatidae, the skin microbiome is exposed to the alkaloids that the frogs sequester from their diet and use for defense. Given the demonstrated antimicrobial effects of these poison frog alkaloids, these compounds may be structuring the skin microbial community. To test this, we first characterized microbial communities from chemically defended and closely related non-defended frogs from Ecuador. Then we conducted a laboratory experiment to monitor the effect of the alkaloid decahydroquinoline (DHQ) on the microbiome of a single frog species. In both the field and lab experiments, we found that alkaloid-exposed microbiomes are more species rich and phylogenetically diverse, with an increase in rare taxa. To better understand the strain-specific behavior in response to alkaloids, we cultured microbial strains from poison frog skin and found the majority of strains exhibited either enhanced growth or were not impacted by the addition of DHQ. Additionally, stable isotope tracing coupled to nanoSIMS suggests that some of these strains are able to metabolize DHQ. Taken together, these data suggest that poison frog chemical defenses open new niches for skin-associated microbes with specific adaptations, including the likely metabolism of alkaloids, that enable their survival in this toxic environment. This work helps expand our understanding of how exposure to exogenous compounds like alkaloids can impact host microbiomes.
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Amphibians are ideal for studying visual system evolution because their biphasic (aquatic and terrestrial) life history and ecological diversity expose them to a broad range of visual conditions. Here, we evaluate signatures of selection on visual opsin genes across Neotropical anurans and focus on three diurnal clades that are well-known for the concurrence of conspicuous colors and chemical defense (i.e., aposematism): poison frogs (Dendrobatidae), Harlequin toads (Bufonidae: Atelopus), and pumpkin toadlets (Brachycephalidae: Brachycephalus). We found evidence of positive selection on 44 amino acid sites in LWS, SWS1, SWS2, and RH1 opsin genes, of which one in LWS and two in RH1 have been previously identified as spectral tuning sites in other vertebrates. Given that anurans have mostly nocturnal habits, the patterns of selection revealed new sites that might be important in spectral tuning for frogs, potentially for adaptation to diurnal habits and for color-based intraspecific communication. Furthermore, we provide evidence that SWS2, normally expressed in rod cells in frogs and some salamanders, has likely been lost in the ancestor of Dendrobatidae, suggesting that under low-light levels, dendrobatids have inferior wavelength discrimination compared to other frogs. This loss might follow the origin of diurnal activity in dendrobatids and could have implications for their behavior. Our analyses show that assessments of opsin diversification in across taxa could expand our understanding of the role of sensory system evolution in ecological adaptation.
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Opsinas , Venenos , Animais , Opsinas/genética , Filogenia , Opsinas de Bastonetes/genéticaRESUMO
IMPORTANCE: Globally, caries is among the most frequent chronic childhood disease, and the fungal component of the microbial community responsible is poorly studied despite evidence that fungi contribute to increased acid production exacerbating enamel demineralization. HIV infection is another global health crisis. Perinatal HIV exposure with infection are caries risk factors; however, the caries experience in the context of perinatal HIV exposure without infection is less clear. Using high-throughput amplicon sequencing, we find taxonomic differences that become pronounced during late-stage caries. Notably, we show a stronger correlation with health-associated taxa for HIV-exposed-but-uninfected children when compared to unexposed and uninfected children. This aligns with a lower incidence of caries in primary teeth at age 6 or less for exposed yet uninfected children. Ultimately, these findings could contribute to improved risk assessment, intervention, and prevention strategies such as biofilm disruption and the informed design of pro-, pre-, and synbiotic oral therapies.
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Infecções por HIV , Microbiota , Micobioma , Criança , Gravidez , Feminino , Humanos , Infecções por HIV/epidemiologia , Fatores de Risco , BiofilmesRESUMO
Electroporation is an increasingly common technique used for exogenous gene expression in live animals, but protocols are largely limited to traditional laboratory organisms. The goal of this protocol is to test in vivo electroporation techniques in a diverse array of tadpole species. We explore electroporation efficiency in tissue-specific cells of five species from across three families of tropical frogs: poison frogs (Dendrobatidae), cryptic forest/poison frogs (Aromobatidae), and glassfrogs (Centrolenidae). These species are well known for their diverse social behaviors and intriguing physiologies that coordinate chemical defenses, aposematism, and/or tissue transparency. Specifically, we examine the effects of electrical pulse and injection parameters on species- and tissue-specific transfection of plasmid DNA in tadpoles. After electroporation of a plasmid encoding green fluorescent protein (GFP), we found strong GFP fluorescence within brain and muscle cells that increased with the amount of DNA injected and electrical pulse number. We discuss species-related challenges, troubleshooting, and outline ideas for improvement. Extending in vivo electroporation to non-model amphibian species could provide new opportunities for exploring topics in genetics, behavior, and organismal biology.
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Terapia com Eletroporação , Eletroporação , Animais , DNA , Plasmídeos/genética , Transfecção , Anuros/genética , Proteínas de Fluorescência Verde/genéticaRESUMO
Children living with HIV have a higher prevalence of oral diseases, including caries, but the mechanisms underlying this higher prevalence are not well understood. Here, we test the hypothesis that HIV infection is associated with a more cariogenic oral microbiome, characterized by an increase in bacteria involved in the pathogenesis of caries. We present data generated from supragingival plaques collected from 484 children representing three exposure groups: (i) children living with HIV (HI), (ii) children who were perinatally exposed but uninfected (HEU), and (iii) unexposed and therefore uninfected children (HUU). We found that the microbiome of HI children is distinct from those of HEU and HUU children and that this distinction is more pronounced in diseased teeth than healthy teeth, suggesting that the impact of HIV is more severe as caries progresses. Moreover, we report both an increase in bacterial diversity and a decrease in community similarity in our older HI cohort compared to our younger HI cohort, which may in part be a prolonged effect of HIV and/or its treatment. Finally, while Streptococcus mutans is often a dominant species in late-stage caries, it tended to be found at lower frequency in our HI cohort than in other groups. Our results highlight the taxonomic diversity of the supragingival plaque microbiome and suggest that broad and increasingly individualistic ecological shifts are responsible for the pathogenesis of caries in children living with HIV, coupled with a diverse and possibly severe impact on known cariogenic taxa that potentially exacerbates caries. IMPORTANCE Since its recognition as a global epidemic in the early 1980s, approximately 84.2 million people have been diagnosed with HIV and 40.1 million people have died from AIDS-related illnesses. The development and increased global availability of antiretroviral treatment (ART) regimens have dramatically reduced the mortality rate of HIV and AIDS, yet approximately 1.5 million new infections were reported in 2021, 51% of which are in sub-Saharan Africa. People living with HIV have a higher prevalence of caries and other chronic oral diseases, the mechanisms of which are not well understood. Here, we used a novel genetic approach to characterize the supragingival plaque microbiome of children living with HIV and compared it to the microbiomes of uninfected and perinatally exposed children to better understand the role of oral bacteria in the etiology of tooth decay in the context of HIV exposure and infection.
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Cárie Dentária , Infecções por HIV , Microbiota , Humanos , Criança , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Microbiota/genética , Antirretrovirais/uso terapêutico , Streptococcus mutans , África Subsaariana , Cárie Dentária/epidemiologiaRESUMO
Motor function is a critical aspect of social signaling in a wide range of taxa. The transcription factor FoxP2 is well studied in the context of vocal communication in humans, mice, and songbirds, but its role in regulating social signaling in other vertebrate taxa is unclear. We examined the distribution and activity of FoxP2-positive neurons in tadpoles of the mimetic poison frog (Ranitomeya imitator). In this species, tadpoles are reared in isolated plant nurseries and are aggressive to other tadpoles. Mothers provide unfertilized egg meals to tadpoles that perform a begging display by vigorously vibrating back and forth. We found that FoxP2 is widely distributed in the tadpole brain and parallels the brain distribution in mammals, birds, and fishes. We then tested the hypothesis that FoxP2-positive neurons would have differential activity levels in begging or aggression contexts compared to non-social controls. We found that FoxP2-positive neurons showed increased activation in the striatum and cerebellum only during begging. Overall, this work suggests a generalizable role for FoxP2 in social signaling across terrestrial vertebrates.
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Reliably capturing transient animal behavior in the field and laboratory remains a logistical and financial challenge, especially for small ectotherms. Here, we present a camera system that is affordable, accessible, and suitable to monitor small, cold-blooded animals historically overlooked by commercial camera traps, such as small amphibians. The system is weather-resistant, can operate offline or online, and allows collection of time-sensitive behavioral data in laboratory and field conditions with continuous data storage for up to four weeks. The lightweight camera can also utilize phone notifications over Wi-Fi so that observers can be alerted when animals enter a space of interest, enabling sample collection at proper time periods. We present our findings, both technological and scientific, in an effort to elevate tools that enable researchers to maximize use of their research budgets. We discuss the relative affordability of our system for researchers in South America, which is home to the largest population of ectotherm diversity.
RESUMO
Many ant species are equipped with chemical defenses, although how these compounds impact nervous system function is unclear. Here, we examined the utility of Caenorhabditis elegans chemotaxis assays for investigating how ant chemical defense compounds are detected by heterospecific nervous systems. We found that C. elegans respond to extracts from the invasive Argentine Ant ( Linepithema humile ) and the osm-9 ion channel is required for this response. Divergent strains varied in their response to L. humile extracts, suggesting genetic variation underlying chemotactic responses. These experiments were conducted by an undergraduate laboratory course, highlighting how C. elegans chemotaxis assays in a classroom setting can provide genuine research experiences and reveal new insights into interspecies interactions.