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OBJECTIVES: The new data provide an important genomic resource for the Critically Endangered Cuban crocodile (Crocodylus rhombifer). Cuban crocodiles are restricted to the Zapata Swamp in southern Matanzas Province, Cuba, and readily hybridize with the widespread American crocodile (Crocodylus acutus) in areas of sympatry. The reported de novo assembly will contribute to studies of crocodylian evolutionary history and provide a resource for informing Cuban crocodile conservation. DATA DESCRIPTION: The final 2.2 Gb draft genome for C. rhombifer consists of 41,387 scaffolds (contigs: N50 = 104.67 Kb; scaffold: N50-518.55 Kb). Benchmarking Universal Single-Copy Orthologs (BUSCO) identified 92.3% of the 3,354 genes in the vertebrata_odb10 database. Approximately 42% of the genome (960Mbp) comprises repeat elements. We predicted 30,138 unique protein-coding sequences (17,737 unique genes) in the genome assembly. Functional annotation found the top Gene Ontology annotations for Biological Processes, Molecular Function, and Cellular Component were regulation, protein, and intracellular, respectively. This assembly will support future macroevolutionary, conservation, and molecular studies of the Cuban crocodile.
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Caimanes y Cocodrilos , Genoma , Anotación de Secuencia Molecular , Caimanes y Cocodrilos/genética , Animales , Genoma/genética , Cuba , Genómica/métodosRESUMEN
Crocodylians globally face considerable challenges, including population decline and extensive habitat modification. Close monitoring of crocodylian populations and their habitats is imperative for the timely detection of population trends, especially in response to management interventions. Here we use eDNA metabarcoding to identify the Critically Endangered Crocodylus rhombifer and the Vulnerable C. acutus, as well as vertebrate community diversity, in Cuba's Zapata Swamp. We tested four different primer sets, including those used previously in Crocodylus population genetic and phylogenetic research, for their efficiency at detecting crocodylian eDNA. We detected C. rhombifer eDNA in 11 out of 15 sampled locations within its historical geographic distribution. We found that data analyses using the VertCOI primers and the mBRAVE bioinformatics pipeline were the most effective molecular marker and pipeline combination for identifying this species from environmental samples. We also identified 55 vertebrate species in environmental samples across the four bioinformatics pipelines- ~ 85% known to be present in the Zapata ecosystem. Among them were eight species previously undetected in the area and eight alien species, including known predators of hatchling crocodiles (e.g., Clarias sp.) and egg predators (e.g., Mus musculus). This study highlights eDNA metabarcoding as a powerful tool for crocodylian biomonitoring within fragile and diverse ecosystems, particularly where fast, non-invasive methods permit detection in economically important areas and will lead to a better understanding of complex human-crocodile interactions and evaluate habitat suitability for potential reintroductions or recovery programs for threatened crocodylian species.
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Caimanes y Cocodrilos , ADN Ambiental , Humanos , Ratones , Animales , Ecosistema , Monitoreo Biológico , ADN Ambiental/genética , Caimanes y Cocodrilos/genética , Humedales , Filogenia , Cuba , Vertebrados/genética , Especies en Peligro de Extinción , Monitoreo del Ambiente/métodos , Código de Barras del ADN Taxonómico , BiodiversidadRESUMEN
Tens of millions of dried seahorses (genus Hippocampus) are traded annually, and the pressure from this trade along with their life history traits (involved parental care and small migration distances and home ranges) has led to near global population declines. This and other forms of overexploitation have led to all seahorse species being listed in Appendix II under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The signatory nations of CITES recommended a 10-cm size limit of seahorses to ensure harvested individuals have reached reproductive maturity, and have thus had the chance to produce offspring, to maintain a more sustainable global seahorse fishery. We assessed adherence to CITES recommendations using DNA barcoding and size measurements to compare two prominent U.S. dried seahorse markets: (1) traditional Chinese medicine (TCM), and (2) non-medicinal ecommerce and coastal curio (ECC). We also estimated U.S. import abundance from CITES records. Of the nine species identified among all samples (n = 532), eight were found in the TCM trade (n = 168); composed mostly (75%) of the Indo-Pacific species Hippocampus trimaculatus, and Hippocampus spinosissimus, and the Latin American Hippocampus ingens. In contrast, ECC samples (n = 344) included 5 species, primarily juvenile Indo-Pacific Hippocampus kuda (51.5%) and the western Atlantic Hippocampus zosterae (40.7). The majority of TCM samples (85.7%) met the CITES size recommendation, in contrast to 4.8% of ECC samples. These results suggest non-size discriminatory bycatch is the most likely source of imported ECC specimens. In addition, CITES records indicate that approximately 602,275 dried specimens were imported into the U.S. from 2004-2020, but the exact species composition remains unknown as many U.S. imports records list one species or Hippocampus spp. from confiscated shipments due to difficulties in morphological identification and large numbers of individuals per shipment. Molecular identification was used to identify the species composition of confiscated shipment imports containing undesignated species, and similar to TCM, found H. trimaculatus and H. spinosissimus the most abundant. By combining DNA barcoding, size comparisons, and CITES database records, these results provide an important glimpse into the two primary dried U.S. seahorse end-markets, and may further inform the conservation status of several Hippocampus species.
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Smegmamorpha , Humanos , Animales , Smegmamorpha/genética , Medicina Tradicional China , Comercio , Internacionalidad , Especies en Peligro de ExtinciónRESUMEN
The scarlet macaw, Ara macao, is a neotropical parrot that contains two described subspecies with broadly discrete geographical distributions. One subspecies, A. m. macao, is found from South America north into southwestern Costa Rica, while the second subspecies, A. m. cyanoptera, is found from eastern Costa Rica north into central Mexico. Our previous research using mitochondrial data to examine phylogeographical divergence across the collective range of these two subspecies concluded that they represent distinct evolutionary entities, with minimal contemporary hybridization between them. Here we further examine phylogenetic relationships and patterns of genetic variation between these two subspecies using a dataset of genetic markers derived from their nuclear genomes. Our analyses show clear nuclear divergence between A. m. macao and A. m. cyanoptera in Central America. Collectively however, samples from this region appear genetically more similar to one another than they do to the examined South American (Brazilian) A. m. macao sample. This observation contradicts our previous assessments based on mitochondrial DNA analyses that A. m. macao in Central and South America represent a single phylogeographical group that is evolutionarily distinct from Central American A. m. cyanoptera. Nonetheless, in agreement with our previous findings, ongoing genetic exchange between the two subspecies appears limited. Rather, our analyses indicate that incomplete lineage sorting is the best supported explanation for cytonuclear discordance within these parrots. High-altitude regions in Central America may act as a reproductive barrier, limiting contemporary hybridization between A. m. macao and A. m. cyanoptera. The phylogeographic complexities of scarlet macaw taxa in this region highlight the need for additional evolutionary examinations of these populations.
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Loros , Animales , Filogenia , Macao , Loros/genética , América Central , BrasilRESUMEN
Partial agonists of peripheral cannabinoid receptors (CBRs) have potential therapeutic applications in several medical conditions. However, (-)-trans-Δ9-tetrahydrocannabinol (THC), the principal active component of marijuana, which is a partial agonist of CB1 and CB2 penetrates the central nervous system (CNS) and produces adverse effects. Peripherally restricted partial agonists of CBRs, particularly of CB1, can be used to treat illnesses safely and effectively with a better therapeutic index. Here, we report on our efforts to synthesize pyrazole partial CBR agonists with peripheral selectivity, resulting in lead compound 40. This compound is a potent partial agonist of CB1 with â¼ 5-fold higher plasma biodistribution over brain and represents an early lead for optimization.
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Agonistas de Receptores de Cannabinoides , Dronabinol , Agonistas de Receptores de Cannabinoides/farmacología , Distribución Tisular , Pirazoles/farmacología , Receptores de Cannabinoides , Receptor Cannabinoide CB1 , Receptor Cannabinoide CB2RESUMEN
Introduction: Excessive alcohol consumption can result in alcoholic liver disease (ALD). There is no FDA-approved drug to specifically treat ALD and current management approaches have limited efficacy. Past studies indicate that monoacylglycerol lipase (MAGL) inhibition can have a positive impact on nonalcoholic fatty liver disease. However, the effect of MAGL inhibition in ALD has not been reported. Materials and Methods: We tested the highly selective and clinically evaluated MAGL inhibitor ABX-1431 in the Lieber-DeCarli liquid alcohol diet-induced model of ALD in C57BL/6 mice. Results: ABX-1431 failed to reduce ALD-associated steatosis and elevated levels of liver enzymes associated with hepatic injury. Furthermore, survival rate declined with increasing doses of ABX-1431 when compared with mice administered vehicle only. Conclusion: These data suggest that MAGL inhibition does not improve ALD and is unlikely to be a good strategy for this condition.
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Selective modulation of peripheral cannabinoid receptors (CBRs) has potential therapeutic applications in medical conditions, including obesity, diabetes, liver diseases, GI disorders and pain. While there have been considerable efforts to produce selective antagonists or full agonists of CBRs, there has been limited reports on the development of partial agonists. Partial agonists targeting peripheral CBRs may have desirable pharmacological profiles while not producing centrally mediated dissociative effects. Bayer reported that BAY 59-3074 is a CNS penetrant partial agonist of both CB1 and CB2 receptors with efficacy in rat models of neuropathic and inflammatory pain. In this report, we demonstrate our efforts to synthesize analogs that would favor peripheral selectivity, while maintaining partial agonism of CB1. Our efforts led to the identification of a novel compound, which is a partial agonist of the human CB1 (hCB1) receptor with vastly diminished brain exposure compared to BAY 59-3074.
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Agonistas de Receptores de Cannabinoides , Dolor , Alcanosulfonatos , Animales , Agonistas de Receptores de Cannabinoides/farmacología , Humanos , Nitrilos , Dolor/tratamiento farmacológico , Ratas , Receptor Cannabinoide CB1 , Receptor Cannabinoide CB2 , Receptores de Cannabinoides , Relación Estructura-ActividadRESUMEN
Metabolic syndrome (MetS) is a complex disorder that stems from the additive effects of multiple underlying causes such as obesity, insulin resistance, and chronic low-grade inflammation. The endocannabinoid system plays a central role in appetite regulation, energy balance, lipid metabolism, insulin sensitivity, and ß-cell function. The type 1 cannabinoid receptor (CB1R) antagonist SR141716A (rimonabant) showed promising antiobesity effects, but its use was discontinued due to adverse psychiatric events in some users. These adverse effects are due to antagonism of CB1R in the central nervous system (CNS). As such, CNS-sparing CB1R antagonists are presently being developed for various indications. In this study, we report that a recently described compound, 3-{1-[8-(2-chlorophenyl)-9-(4-chlorophenyl)-9H-purin-6-yl]piperidin-4-yl}-1-[6-(difluoromethoxy)pyridin-3-yl]urea (RTI1092769), a pyrazole based weak inverse agonist/antagonist of CB1 with very limited brain exposure, improves MetS related complications. Treatment with RTI1092769 inhibited weight gain and improved glucose utilization in obese mice maintained on a high fat diet. Hepatic triglyceride content and steatosis significantly improved with treatment. These phenotypes were supported by improvement in several biomarkers associated with nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). These results reinforce the idea that CB1 antagonists with limited brain exposure should be pursued for MetS and other important indications.
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Developing-world shark fisheries are typically not assessed or actively managed for sustainability; one fundamental obstacle is the lack of species and size-composition catch data. We tested and implemented a new and potentially widely applicable approach for collecting these data: mandatory submission of low-value secondary fins (anal fins) from landed sharks by fishers and use of the fins to reconstruct catch species and size. Visual and low-cost genetic identification were used to determine species composition, and linear regression was applied to total length and anal fin base length for catch-size reconstruction. We tested the feasibility of this approach in Belize, first in a local proof-of-concept study and then scaling it up to the national level for the 2017-2018 shark-fishing season (1,786 fins analyzed). Sixteen species occurred in this fishery. The most common were the Caribbean reef (Carcharhinus perezi), blacktip (C. limbatus), sharpnose (Atlantic [Rhizoprionodon terraenovae] and Caribbean [R. porosus] considered as a group), and bonnethead (Sphyrna cf. tiburo). Sharpnose and bonnethead sharks were landed primarily above size at maturity, whereas Caribbean reef and blacktip sharks were primarily landed below size at maturity. Our approach proved effective in obtaining critical data for managing the shark fishery, and we suggest the tools developed as part of this program could be exported to other nations in this region and applied almost immediately if there were means to communicate with fishers and incentivize them to provide anal fins. Outside the tropical Western Atlantic, we recommend further investigation of the feasibility of sampling of secondary fins, including considerations of time, effort, and cost of species identification from these fins, what secondary fin type to use, and the means with which to communicate with fishers and incentivize participation. This program could be a model for collecting urgently needed data for developing-world shark fisheries globally. Article impact statement: Shark fins collected from fishers yield data critical to shark fisheries management in developing nations.
Uso de Aletas Secundarias Proporcionadas por Pescadores para Llenar Vacíos Importantes de Información sobre las Pesquerías de Tiburones Resumen Con frecuencia no se evalúan las pesquerías de tiburones del mundo en desarrollo ni cuentan con un manejo activo de sustentabilidad. Uno de los principales obstáculos para esto es la falta de información sobre las especies y la composición de los tamaños en las capturas. Probamos e implementamos una estrategia nueva y potencialmente aplicable en todas partes para la recolección de estos datos: la entrega obligatoria de las aletas secundarias de bajo valor económico (aletas anales) obtenidas de los tiburones desembarcados por parte de los pescadores y el uso de estas aletas para reconstruir las especies y tamaños en la captura. Usamos identificaciones genéticas de bajo costo e identificaciones visuales para determinar la composición de las especies y aplicamos una regresión lineal a la longitud total y a la de la base de la aleta anal para la reconstrucción del tamaño en captura. Probamos la viabilidad de esta estrategia en Belice, primero en un estudio de prueba de concepto y después subiendo al nivel nacional para la temporada de pesca de tiburón 2017-2018 (1,786 aletas analizadas). Se registraron 16 especies en esta pesquería. Las más comunes fueron Carcharhinus perezi, C. limbatus, Rhizoprionodon terraenovae y R. porosus (consideradas como un grupo) y Sphyrna cf. tiburo. Las últimas tres especies fueron desembarcadas principalmente por encima del tamaño maduro, mientras que con las dos primeras especies lo hacían por debajo del tamaño maduro. Nuestra estrategia demostró ser efectiva en la obtención de información crítica para el manejo de la pesquería de tiburones y sugerimos que las herramientas desarrolladas como parte de este programa puedan ser exportadas a otras naciones en esta región y aplicadas casi de manera inmediata si existen los medios para comunicarse con los pescadores e incentivarlos a proporcionar las aletas anales. Fuera del Atlántico Occidental tropical, recomendamos una mayor investigación de la viabilidad del muestreo de aletas secundarias, incluyendo la consideración del tiempo, esfuerzo y costo de la identificación de especies a partir de estas aletas; cuál tipo de aleta secundaria utilizar; y los medios mediante los cuales comunicarse con los pescadores e incentivarlos a participar. Este programa podría ser un modelo para la recolección de información de necesidad urgente para las pesquerías del mundo en desarrollo.
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Mustelidae , Tiburones , Animales , Conservación de los Recursos Naturales , Explotaciones Pesqueras , Alimentos MarinosRESUMEN
The Mediterranean monk seal (Monachus monachus) is a flagship species for marine conservation, but important aspects of its life history remain unknown. Concerns over imminent extinction motivated a nuclear DNA study of the species in its largest continuous subpopulation in the eastern Mediterranean Sea. Despite recent evidence of partial subpopulation recovery, we demonstrate that there is no reason for complacency, as the species still shares several traits that are characteristic of a critically endangered species: Mediterranean monk seals in the eastern Mediterranean survive in three isolated and genetically depauperate population clusters, with small effective population sizes and high levels of inbreeding. Our results indicated male philopatry over short distances, which is unexpected for a polygynous mammal. Such a pattern may be explained by the species' unique breeding behavior, in which males defend aquatic territories near breeding sites, while females are often forced to search for new pupping areas. Immediate action is necessary to reverse the downward spiral of population decline, inbreeding accumulation and loss of genetic diversity. We propose concrete conservation measures for the Mediterranean monk seal focusing on reducing anthropogenic threats, increasing the population size and genetic diversity, and thus improving the long-term prospects of survival.
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Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción , Phocidae , Distribución Animal/fisiología , Animales , Caniformia/clasificación , Conservación de los Recursos Naturales/historia , ADN Mitocondrial/análisis , Demografía , Ecosistema , Especies en Peligro de Extinción/historia , Pruebas Genéticas/veterinaria , Variación Genética/fisiología , Grecia/epidemiología , Historia del Siglo XX , Mar Mediterráneo , Densidad de Población , Dinámica Poblacional/historia , Phocidae/genéticaRESUMEN
Extant species in the order Crocodylia are remnants of an ancient lineage of large-bodied archosaur reptiles. Despite decades of systematic studies, phylogenetic relationships among members of the genus Crocodylus (true crocodiles) in the Neotropics are poorly understood. Here we estimated phylogenomic relationships among the four extant Crocodylus species in the Americas. Species-tree reconstructions using genotypic data from 17,538 SNPs collected for 33 individuals spanning six Crocodylus species (four ingroup and two outgroup) revealed novel relationships for all Neotropical species. For the first time, C. acutus, the American crocodile, was recovered as monophyletic when individuals from Antillean and continental populations were analyzed together. Our results also contradict previous inferences based on mitochondrial DNA data and a limited number of nuclear markers by robustly grouping Morelet's crocodile (C. moreletii) as the sister species to C. acutus, suggesting a novel phylogeographic hypothesis for the group. The present study punctuates the importance of using nuclear genome-wide information and representative sampling for resolving phylogenetic relationships, especially in broadly distributed species and those with complex evolutionary histories.
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Caimanes y Cocodrilos/clasificación , Caimanes y Cocodrilos/genética , Filogenia , Américas , Animales , ADN Mitocondrial/genética , Genotipo , FilogeografíaRESUMEN
The American crocodile (Crocodylus acutus) is a widely distributed species across coastal and brackish areas of the Neotropical region of the Americas and the Greater Antilles. Available information on patterns of genetic differentiation in C. acutus shows a complex structuring influenced by interspecific interactions (mainly hybridization) and anthropogenic actions (mostly historical hunting, recent poaching, habitat loss and fragmentation, and unintentional translocation of individuals). In this study, we used data on mitochondrial DNA control region and 11 nuclear polymorphic microsatellite loci to assess the degree of population structure of C. acutus in South America, North America, Central America and the Greater Antilles. We used traditional genetic differentiation indices, Bayesian clustering and multivariate methods to create a more comprehensive picture of the genetic relationships within the species across its range. Analyses of mtDNA and microsatellite loci show evidence of a strong population genetic structure in the American crocodile, with unique populations in each sampling locality. Our results support previous findings showing large degrees of genetic differentiation between the continental and the Greater Antillean C. acutus. We report three new haplotypes unique to Venezuela, which are considerably less distant from the Central and North American haplotypes than to the Greater Antillean ones. Our findings reveal genetic population differentiation between Cuban and Jamaican C. acutus and offer the first evidence of strong genetic differentiation among the populations of Greater Antillean C. acutus.
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Caimanes y Cocodrilos/genética , Animales , Región del Caribe , América Central , ADN Mitocondrial/genética , Variación Genética , Genética de Población , Haplotipos , Repeticiones de Microsatélite , Mitocondrias/genética , América del Norte , América del SurRESUMEN
For more than thirty years, methods and theories from evolutionary biology, phylogenetics, population genetics and molecular biology have been used by conservation biologists to better understand threats to endangered species due to anthropogenic changes [...].
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Especies en Peligro de Extinción , Genómica/métodos , Animales , Técnicas GenéticasRESUMEN
The structure and connectivity of wildlife host populations may influence zoonotic disease dynamics, evolution and therefore spillover risk to people. Fruit bats in the genus Pteropus, or flying foxes, are the primary natural reservoir for henipaviruses-a group of emerging paramyxoviruses that threaten livestock and public health. In Bangladesh, Pteropus medius is the reservoir for Nipah virus-and viral spillover has led to human fatalities nearly every year since 2001. Here, we use mitochondrial DNA and nuclear microsatellite markers to measure the population structure, demographic history and phylogeography of P. medius in Bangladesh. We combine this with a phylogeographic analysis of all known Nipah virus sequences and strains currently available to better inform the dynamics, distribution and evolutionary history of Nipah virus. We show that P. medius is primarily panmictic, but combined analysis of microsatellite and morphological data shows evidence for differentiation of two populations in eastern Bangladesh, corresponding to a divergent strain of Nipah virus also found in bats from eastern Bangladesh. Our demographic analyses indicate that a large, expanding population of flying foxes has existed in Bangladesh since the Late Pleistocene, coinciding with human population expansion in South Asia, suggesting repeated historical spillover of Nipah virus likely occurred. We present the first evidence of mitochondrial introgression, or hybridization, between P. medius and flying fox species found in South-East Asia (P. vampyrus and P. hypomelanus), which may help to explain the distribution of Nipah virus strains across the region.
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Quirópteros/genética , Quirópteros/virología , Genética de Población , Virus Nipah/genética , Animales , Bangladesh , Quirópteros/clasificación , ADN Mitocondrial/genética , Femenino , Masculino , Repeticiones de Microsatélite , Virus Nipah/clasificación , FilogeografíaRESUMEN
BACKGROUND: Connectivity among jaguar (Panthera onca) populations will ensure natural gene flow and the long-term survival of the species throughout its range. Jaguar conservation efforts have focused primarily on connecting suitable habitat in a broad-scale. Accelerated habitat reduction, human-wildlife conflict, limited funding, and the complexity of jaguar behaviour have proven challenging to maintain connectivity between populations effectively. Here, we used non-invasive genetic sampling and individual-based conservation genetic analyses to assess genetic diversity and levels of genetic connectivity between individuals in the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We used expert knowledge and scientific literature to develop models of landscape permeability based on circuit theory with fine-scale landscape features as ecosystem types, distance to human settlements and roads to predict the most probable jaguar movement across central Belize. RESULTS: We used 12 highly polymorphic microsatellite loci to identify 50 individual jaguars. We detected high levels of genetic diversity across loci (HE = 0.61, HO = 0.55, and NA = 9.33). Using Bayesian clustering and multivariate models to assess gene flow and genetic structure, we identified one single group of jaguars (K = 1). We identified critical areas for jaguar movement that fall outside the boundaries of current protected areas in central Belize. We detected two main areas of high landscape permeability in a stretch of approximately 18 km between Sittee River Forest Reserve and Manatee Forest Reserve that may increase functional connectivity and facilitate jaguar dispersal from and to Cockscomb Basin Wildlife Sanctuary. Our analysis provides important insights on fine-scale genetic and landscape connectivity of jaguars in central Belize, an area of conservation concern. CONCLUSIONS: The results of our study demonstrate high levels of relatively recent gene flow for jaguars between two study sites in central Belize. Our landscape analysis detected corridors of expected jaguar movement between the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We highlight the importance of maintaining already established corridors and consolidating new areas that further promote jaguar movement across suitable habitat beyond the boundaries of currently protected areas. Continued conservation efforts within identified corridors will further maintain and increase genetic connectivity in central Belize.
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Variación Genética , Genética de Población/métodos , Panthera/genética , Animales , Belice , Conservación de los Recursos Naturales , Ecosistema , Evolución Molecular , Flujo Génico , Repeticiones de MicrosatéliteRESUMEN
Antagonists of type 1 cannabinoid receptors (CB1) may be useful in treating diabetes, hepatic disorders, and fibrosis. Otenabant (1) is a potent and selective CB1 inverse agonist that was under investigation as an anti-obesity agent, but its development was halted once adverse effects associated with another marketed inverse agonist rimonabant (2) became known. Non-tissue selective antagonists of CB1 that have high levels of brain penetration produce adverse effects in a small subset of patients including anxiety, depression and suicidal ideation. Currently, efforts are underway to produce compounds that have limited brain penetration. In this report, novel analogs of 1 are explored to develop and test strategies for peripheralization. The piperidine of 1 is studied as a linker, which is functionalized with alkyl, heteroalkyl, aryl and heteroaryl groups using a connector in the form of an amine, amide, sulfonamide, sulfamide, carbamate, oxime, amidine, or guanidine. We also report more polar replacements for the 4-chlorophenyl group in the 9-position of the purine core, which improve calculated physical properties of the molecules. These studies resulted in compounds such as 75 that are potent inverse agonists of hCB1 with exceptional selectivity for hCB1 over hCB2. SAR studies revealed ways to adjust physical properties to limit brain exposure.
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Purinas/química , Receptor Cannabinoide CB1/química , Humanos , Estructura Molecular , Relación Estructura-ActividadRESUMEN
Peripherally restricted CB1 receptor antagonists may be useful in treating metabolic syndrome, diabetes, liver diseases, and gastrointestinal disorders. Clinical development of the centrally acting CB1 inverse agonist otenabant (1) was halted due to its potential of producing adverse effects. SAR studies of 1 are reported herein with the objective of producing peripherally restricted analogues. Crystal structures of hCB1 and docking studies with 1 indicate that the piperidine group could be functionalized at the 4-position to access a binding pocket that can accommodate both polar and nonpolar groups. The piperidine is studied as a linker, functionalized with alkyl, heteroalkyl, aryl, and heteroaryl groups using a urea connector. Orally bioavailable and peripherally selective compounds have been produced that are potent inverse agonists of hCB1 with exceptional selectivity for hCB1 over hCB2. Compound 38 blocked alcohol-induced liver steatosis in mice and has good ADME properties for further development.
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Antagonistas de Receptores de Cannabinoides/farmacología , Piperidinas/farmacología , Purinas/farmacología , Receptor Cannabinoide CB1/agonistas , Animales , Antagonistas de Receptores de Cannabinoides/síntesis química , Antagonistas de Receptores de Cannabinoides/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Perros , Agonismo Inverso de Drogas , Hígado Graso/patología , Hígado Graso/prevención & control , Femenino , Humanos , Hígado/patología , Células de Riñón Canino Madin Darby , Ratones Endogámicos C57BL , Simulación del Acoplamiento Molecular , Estructura Molecular , Piperidinas/síntesis química , Piperidinas/metabolismo , Purinas/síntesis química , Purinas/metabolismo , Ratas Sprague-Dawley , Receptor Cannabinoide CB1/metabolismo , Relación Estructura-ActividadRESUMEN
INTRODUCTION: The endocannabinoid system is an important regulator of various physiological processes. Preclinical and clinical studies indicate that attenuation of the endocannabinoid system via antagonism of the type 1 cannabinoid receptor (CB1) is an excellent strategy to treat obesity, metabolic syndrome and associated disorders. However, centrally acting antagonists of CB1 also produce adverse effects like depression and anxiety. Current efforts are geared towards discovery and optimization of antagonists and modulators of CB1 that have limited brain penetration. AREAS COVERED: Several recent publications and patent applications support the development of peripherally acting CB1 receptor antagonists and modulators. In this review, recent patents and applications (2015-2018) are summarized and discussed. EXPERT OPINION: Approximately 30 new inventions have been reported since 2015, along with 3 recent commercial deals, highlighting the importance of this class of therapeutics. Taken together, peripherally acting CB1 receptor antagonists and modulators are an emerging class of drugs for metabolic syndrome, non-alcoholic steatohepatitis (NASH) and other important disorders where this receptor has been implicated.
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Antagonistas de Receptores de Cannabinoides/farmacología , Endocannabinoides/metabolismo , Receptor Cannabinoide CB1/antagonistas & inhibidores , Animales , Antagonistas de Receptores de Cannabinoides/inmunología , Desarrollo de Medicamentos/métodos , Humanos , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/fisiopatología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/fisiopatología , Obesidad/tratamiento farmacológico , Obesidad/fisiopatología , Patentes como Asunto , Receptor Cannabinoide CB1/metabolismoRESUMEN
The fungus Batrachochytrium dendrobatidis (Bd) is a generalist amphibian pathogen responsible for chytridiomycosis. It was documented for the first time in Cuba in 2007, the apparent cause of the decline in one species of toad. In a recent survey, Bd was reported only for the highlands of Central Cuba. In the present study, we reexamined the geographic distribution and level of impact of Bd in Cuba by conducting an island-wide sampling in 10 localities and collecting skin swabs from 18 species and 28 environmental samples. We report detection of Bd in 60% of sampled sites and in 58% of sampled taxa. We show that Bd is associated with riparian, arboreal and terrestrial species, and it was estimated to occur in approximately 30% of the aquatic habitats we sampled. In addition, we confirmed that a dying individual of the species Eleutherodactylus casparii was severely infected with Bd. We also rise concern about the endanger toad Peltophryne longinasus and about three species of endemic riparian frogs that were not detected during our surveys. This study demonstrates that this pathogen is widespread throughout Cuba and provides relevant evidence to advance our understanding of its detection in amphibians and the aquatic environment in Cuba and about the occurrence of Bd in species with different ecologies. We provide valuable baseline information for Bd risk assessment and decision-making processes to mitigate its negative impact on Cuban amphibians.
Asunto(s)
Anfibios/microbiología , Quitridiomicetos/aislamiento & purificación , Micosis/veterinaria , Animales , Clima , Cuba/epidemiología , ADN de Hongos , Ecosistema , RíosRESUMEN
Four species of true crocodile (genus Crocodylus) have been described from the Americas. Three of these crocodile species exhibit non-overlapping distributions-Crocodylus intermedius in South America, C. moreletii along the Caribbean coast of Mesoamerica, and C. rhombifer confined to Cuba. The fourth, C. acutus, is narrowly sympatric with each of the other three species. In this study, we sampled 113 crocodiles across Crocodylus populations in Cuba, as well as exemplar populations in Belize and Florida (USA), and sequenced three regions of the mitochondrial genome (D-loop, cytochrome b, cytochrome oxidase I; 3,626 base pair long dataset) that overlapped with published data previously collected from Colombia, Jamaica, and the Cayman Islands. Phylogenetic analyses of these data revealed two, paraphyletic lineages of C. acutus. One lineage, found in the continental Americas, is the sister taxon to C. intermedius, while the Greater Antillean lineage is most closely related to C. rhombifer. In addition to the paraphyly of the two C. acutus lineages, we recovered a 5.4% estimate of Tamura-Nei genetic divergence between the Antillean and continental clades. The reconstructed paraphyly, distinct phylogenetic affinities and high genetic divergence between Antillean and continental C. acutus populations are consistent with interspecific differentiation within the genus and suggest that the current taxon recognized as C. acutus is more likely a complex of cryptic species warranting a reassessment of current taxonomy. Moreover, the inclusion, for the first time, of samples from the western population of the American crocodile in Cuba revealed evidence for continental mtDNA haplotypes in the Antilles, suggesting this area may constitute a transition zone between distinct lineages of C. acutus. Further study using nuclear character data is warranted to more fully characterize this cryptic diversity, resolve taxonomic uncertainty, and inform conservation planning in this system.