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1.
Nature ; 592(7853): 205-208, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33828321

RESUMO

The atmospheres of gaseous giant exoplanets orbiting close to their parent stars (hot Jupiters) have been probed for nearly two decades1,2. They allow us to investigate the chemical and physical properties of planetary atmospheres under extreme irradiation conditions3. Previous observations of hot Jupiters as they transit in front of their host stars have revealed the frequent presence of water vapour4 and carbon monoxide5 in their atmospheres; this has been studied in terms of scaled solar composition6 under the usual assumption of chemical equilibrium. Both molecules as well as hydrogen cyanide were found in the atmosphere of HD 209458b5,7,8, a well studied hot Jupiter (with equilibrium temperature around 1,500 kelvin), whereas ammonia was tentatively detected there9 and subsequently refuted10. Here we report observations of HD 209458b that indicate the presence of water (H2O), carbon monoxide (CO), hydrogen cyanide (HCN), methane (CH4), ammonia (NH3) and acetylene (C2H2), with statistical significance of 5.3 to 9.9 standard deviations per molecule. Atmospheric models in radiative and chemical equilibrium that account for the detected species indicate a carbon-rich chemistry with a carbon-to-oxygen ratio close to or greater than 1, higher than the solar value (0.55). According to existing models relating the atmospheric chemistry to planet formation and migration scenarios3,11,12, this would suggest that HD 209458b formed far from its present location and subsequently migrated inwards11,13. Other hot Jupiters may also show a richer chemistry than has been previously found, which would bring into question the frequently made assumption that they have solar-like and oxygen-rich compositions.

2.
Mol Biol Rep ; 50(6): 4851-4863, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37039999

RESUMO

BACKGROUND: The Central American (Mazama temama) and the Yucatán Peninsula brocket deer (Odocoileus pandora) are deer species with cryptic habits, and little is known about their biology. Odocoileus pandora is listed as Vulnerable on the 2015 IUCN Red List of Threatened Species, while M. temama is considered Data Deficient; however, it currently faces a decreasing population trend. METHODS AND RESULTS: We assembled the complete mitochondrial genome for two M. temama specimens and one complete and one partial for O. pandora from Illumina 150 bp paired-end reads. The mitogenomes of M. temama and O. pandora have a length of 16,479-16,480 and 16,419 bp, respectively, AT-biased; they consist of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one non-coding control region, most of them follow a transcription direction in the heavy strand of the molecule. The mitochondrial genome of O. pandora shows some particularities compared to other deer species, like a shorter control region of 987-990 bp and a cytochrome b gene with a length of 1,143 bp. Our phylogenetic analyses confirm the close affinity of M. temama to South American M. americana and the nested position of the genus Odocoileus, including O. pandora, into the genus Mazama. CONCLUSIONS: Here, we described for the first time the complete mitochondrial genome for these two species. While our study provides additional information about the taxonomic status of the northern neotropical brocket deer, further research is needed to solve the complicated taxonomy of neotropical deer.


Assuntos
Cervos , Genoma Mitocondrial , Animais , Filogenia , Genoma Mitocondrial/genética , México , Cervos/genética , América Central
3.
J Hered ; 114(5): 529-538, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37246890

RESUMO

We provide novel genomic resources to help understand the genomic traits involved in elephant health and to aid conservation efforts. We sequence 11 elephant genomes (5 African savannah, 6 Asian) from North American zoos, including 9 de novo assemblies. We estimate elephant germline mutation rates and reconstruct demographic histories. Finally, we provide an in-solution capture assay to genotype Asian elephants. This assay is suitable for analyzing degraded museum and noninvasive samples, such as feces and hair. The elephant genomic resources we present here should allow for more detailed and uniform studies in the future to aid elephant conservation efforts and disease research.


Assuntos
Elefantes , Animais , Elefantes/genética , Genômica , Genoma , Mapeamento Cromossômico , Animais de Zoológico , Mutação em Linhagem Germinativa
4.
J Hered ; 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37886904

RESUMO

The gut microbiome of mammals engages in a dynamic relationship with the body and contributes to numerous physiological processes integral to overall health. Understanding the factors shaping animal-associated bacterial communities is therefore paramount to the maintenance and management in ex situ wildlife populations. Here, we characterized the gut microbiome of 48 endangered black-footed ferrets (Mustela nigripes) housed at Smithsonian's National Zoo and Conservation Biology Institute (Front Royal, Virginia, USA). We collected longitudinal fecal samples from males and females across two distinct reproductive seasons to consider the role of host sex and reproductive physiology in shaping bacterial communities, as measured using 16S rRNA amplicon sequencing. Within each sex, gut microbial composition differed between breeding and non-breeding seasons, with five bacterial taxa emerging as differentially abundant. Between sexes, female and male microbiomes were similar during non-breeding season but significantly different during breeding season, which may result from sex-specific physiological changes associated with breeding. Finally, we found low overall diversity consistent with other mammalian carnivores alongside high relative abundances of potentially pathogenic microbes such as Clostridium, Escherichia, Paeniclostridium, and (to a lesser degree) Enterococcus - all of which have been associated with gastrointestinal or reproductive distress in mammalian hosts, including black-footed ferrets. We recommend further study of these microbes and possible therapeutic interventions to promote more balanced microbial communities. These results have important implications for ex situ management practices that can improve the gut microbial health and long-term viability of black-footed ferrets.

5.
J Hered ; 114(5): 539-548, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37249392

RESUMO

The black-footed ferret (Mustela nigripes) narrowly avoided extinction to become an oft-cited example of the benefits of intensive management, research, and collaboration to save a species through ex situ conservation breeding and reintroduction into its former range. However, the species remains at risk due to possible inbreeding, disease susceptibility, and multiple fertility challenges. Here, we report the de novo genome assembly of a male black-footed ferret generated through a combination of linked-read sequencing, optical mapping, and Hi-C proximity ligation. In addition, we report the karyotype for this species, which was used to anchor and assign chromosome numbers to the chromosome-length scaffolds. The draft assembly was ~2.5 Gb in length, with 95.6% of it anchored to 19 chromosome-length scaffolds, corresponding to the 2n = 38 chromosomes revealed by the karyotype. The assembly has contig and scaffold N50 values of 148.8 kbp and 145.4 Mbp, respectively, and is up to 96% complete based on BUSCO analyses. Annotation of the assembly, including evidence from RNA-seq data, identified 21,406 protein-coding genes and a repeat content of 37.35%. Phylogenomic analyses indicated that the black-footed ferret diverged from the European polecat/domestic ferret lineage 1.6 million yr ago. This assembly will enable research on the conservation genomics of black-footed ferrets and thereby aid in the further restoration of this endangered species.


Assuntos
Espécies em Perigo de Extinção , Furões , Animais , Masculino , Furões/genética , Cariótipo , Cariotipagem , Fertilidade
6.
Sensors (Basel) ; 23(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37112437

RESUMO

Tablas de Daimiel National Park (TDNP) is a unique inland wetland located in the Mancha plain (Spain). It is recognized at the international level, and it is protected by different figures, such as Biosphere Reserve. However, this ecosystem is endangered due to aquifer overexploitation, and it is at risk of losing its protection figures. The objective of our study is to analyze the evolution of the flooded area between the year 2000 and 2021 by Landsat (5, 7 and 8) and Sentinel-2 images, and to assess the TDNP state through an anomaly analysis of the total water body surface. Several water indices were tested, but the NDWI index for Sentinel-2 (threshold -0.20), the MNDWI for Landsat-5 (threshold -0.15), and the MNDWI for Landsat-8 (threshold -0.25) showed the highest accuracy to calculate the flooded surface inside the protected area's limits. During the period 2015-2021, we compared the performance of Landsat-8 and Sentinel-2 and an R2 value of 0.87 was obtained for this analysis, indicating a high correspondence between both sensors. Our results indicate a high variability of the flooded areas during the analyzed period with significant peaks, the most notorious in the second quarter of 2010. Minimum flooded areas were observed with negative precipitation index anomalies since fourth quarter of 2004 to fourth quarter of 2009. This period corresponds to a severe drought that affected this region and caused important deterioration. No significant correlation was observed between water surface anomalies and precipitation anomalies, and the significant correlation with flow and piezometric anomalies was moderate. This can be explained because of the complexity of water uses in this wetland, which includes illegal wells and the geological heterogeneity.

7.
Sensors (Basel) ; 23(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36991910

RESUMO

Ocean color is the result of absorption and scattering, as light interacts with the water and the optically active constituents. The measurement of ocean color changes enables monitoring of these constituents (dissolved or particulate materials). The main objective of this research is to use digital images to estimate the light attenuation coefficient (Kd), the Secchi disk depth (ZSD), and the chlorophyll a (Chla) concentration and to optically classify plots of seawater using the criteria proposed by Jerlov and Forel using digital images captured at the ocean surface. The database used in this study was obtained from seven oceanographic cruises performed in oceanic and coastal areas. Three approaches were developed for each parameter: a general approach that can be applied under any optical condition, one for oceanic conditions, and another for coastal conditions. The results of the coastal approach showed higher correlations between the modeled and validation data, with rp values of 0.80 for Kd, 0.90 for ZSD, 0.85 for Chla, 0.73 for Jerlov, and 0.95 for Forel-Ule. The oceanic approach failed to detect significant changes in a digital photograph. The most precise results were obtained when images were captured at 45° (n = 22; Fr cal=11.02>Fr crit=5.99). Therefore, to ensure precise results, the angle of photography is key. This methodology can be used in citizen science programs to estimate ZSD, Kd, and the Jerlov scale.

8.
Mol Phylogenet Evol ; 167: 107266, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34302947

RESUMO

Four species of spotted skunks (Carnivora, Mephitidae, Spilogale) are currently recognized: Spilogale angustifrons, S. gracilis, S. putorius, and S. pygmaea. Understanding species boundaries within this group is critical for effective conservation given that regional populations or subspecies (e.g., S. p. interrupta) have experienced significant population declines. Further, there may be currently unrecognized diversity within this genus as some taxa (e.g., S. angustifrons) and geographic regions (e.g., Central America) never have been assessed using DNA sequence data. We analyzed species limits and diversification patterns in spotted skunks using multilocus nuclear (ultraconserved elements) and mitochondrial (whole mitogenomes and single gene analysis) data sets from broad geographic sampling representing all currently recognized species and subspecies. We found a high degree of genetic divergence among Spilogale that reflects seven distinct species and eight unique mitochondrial lineages. Initial divergence between S. pygmaea and all other Spilogale occurred in the Early Pliocene (~ 5.0 million years ago). Subsequent diversification of the remaining Spilogale into an "eastern" and a "western" lineage occurred during the Early Pleistocene (~1.5 million years ago). These two lineages experienced temporally coincident patterns of diversification at ~0.66 and ~0.35 million years ago into two and ultimately three distinct evolutionary units, respectively. Diversification was confined almost entirely within the Pleistocene during a timeframe characterized by alternating glacial-interglacial cycles, with the origin of this diversity occurring in northeastern Mexico and the southwestern United States of America. Mitochondrial-nuclear discordance was recovered across three lineages in geographic regions consistent with secondary contact, including a distinct mitochondrial lineage confined to the Sonoran Desert. Our results have direct consequences for conservation of threatened populations, or species, as well as for our understanding of the evolution of delayed implantation in this enigmatic group of small carnivores.


Assuntos
Carnívoros , Mephitidae , Animais , Carnívoros/genética , Mudança Climática , DNA Mitocondrial/genética , Variação Genética , Mephitidae/genética , México , Filogenia , Análise de Sequência de DNA
9.
Mol Phylogenet Evol ; 175: 107576, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35809853

RESUMO

Ultraconserved Elements (UCEs) have been useful to resolve challenging phylogenies of non-model clades, unpuzzling long-conflicted relationships in key branches of the Tree of Life at both deep and shallow levels. UCEs are often reliably recovered from historical samples, unlocking a vast number of preserved natural history specimens for analysis. However, the extent to which sample age and preservation method impact UCE recovery as well as downstream inferences remains unclear. Furthermore, there is an ongoing debate on how to curate, filter, and properly analyze UCE data when locus recovery is uneven across sample age and quality. In the present study we address these questions with an empirical dataset composed of over 3800 UCE loci from 219 historical and modern samples of Sciuridae, a globally distributed and ecologically important family of rodents. We provide a genome-scale phylogeny of two squirrel subfamilies (Sciurillinae and Sciurinae: Sciurini) and investigate their placement within Sciuridae. For historical specimens, recovery of UCE loci and mean length per locus were inversely related to sample age; deeper sequencing improved the number of UCE loci recovered but not locus length. Most of our phylogenetic inferences-performed on six datasets with alternative data-filtering strategies, and using three distinct optimality criteria-resulted in distinct topologies. Datasets containing more loci (40% and 50% taxa representativeness matrices) yielded more concordant topologies and higher support values than strictly filtered datasets (60% matrices) particularly with IQ-Tree and SVDquartets, while filtering based on information content provided better topological resolution for inferences with the coalescent gene-tree based approach in ASTRAL-III. We resolved deep relationships in Sciuridae (including among the five currently recognized subfamilies) and relationships among the deepest branches of Sciurini, but conflicting relationships remain at both genus- and species-levels for the rapid Neotropical tree squirrel radiation. Our results suggest that phylogenomic consensus can be difficult and heavily influenced by the age of available samples and the filtering steps used to optimize dataset properties.


Assuntos
Genoma , Sciuridae , Animais , Filogenia , Sciuridae/genética
10.
Exp Astron (Dordr) ; 53(2): 225-278, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35673554

RESUMO

The goal of the Ariel space mission is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. The planetary bulk and atmospheric compositions bear the marks of the way the planets formed: Ariel's observations will therefore provide an unprecedented wealth of data to advance our understanding of planet formation in our Galaxy. A number of environmental and evolutionary factors, however, can affect the final atmospheric composition. Here we provide a concise overview of which factors and effects of the star and planet formation processes can shape the atmospheric compositions that will be observed by Ariel, and highlight how Ariel's characteristics make this mission optimally suited to address this very complex problem.

11.
Genome ; 64(1): 39-49, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33002384

RESUMO

The Mediterranean region is identified as one of the world's 36 biodiversity hotspots, with the Earth's most biologically rich yet threatened areas. Lebanon is a hub for Eastern Mediterranean Region (EMR) biodiversity with 9116 characterized plant and animal species (4486 fauna and 4630 flora). Using DNA barcoding as a tool has become crucial in the accurate identification of species in multiple contexts. It can also complement species morphological descriptions, which will add to our understanding of the biodiversity and richness of ecosystems and benefit conservation projects for endangered and endemic species. In this study, we create the first reference library of standard DNA markers for mammals and plants in the EMR, with a focus on endemic and endangered species. Plant leaves were collected from different nature reserves in Mount Lebanon, and mammal samples were obtained from taxidermized museum specimens or road kills. We generated the 12S rRNA sequences of 18 mammal species from 6 orders and 13 different families. We also obtained the trnL and rbcL barcode sequences of 52 plant species from 24 different families. Twenty-five plant species and two mammal species included in this study were sequenced for the first time using these markers.


Assuntos
Biblioteca Gênica , Mamíferos/genética , Plantas/genética , Animais , Sequência de Bases , Biodiversidade , Código de Barras de DNA Taxonômico , Ecossistema , Marcadores Genéticos , Região do Mediterrâneo , Folhas de Planta/genética
12.
BMC Evol Biol ; 20(1): 77, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590930

RESUMO

BACKGROUND: Tree squirrels (Sciuridae, Sciurini), in particular the highly diverse Neotropical lineages, are amongst the most rapidly diversifying branches of the mammal tree of life but also some of the least known. Negligence of this group by systematists is likely a product of the difficulties in assessing morphological informative traits and of the scarcity or unavailability of fresh tissue samples for DNA sequencing. The highly discrepant taxonomic arrangements are a consequence of the lack of phylogenies and the exclusive phenotypic-based classifications, which can be misleading in a group with conservative morphology. Here we used high-throughput sequencing and an unprecedented sampling of museum specimens to provide the first comprehensive phylogeny of tree squirrels, with a special emphasis on Neotropical taxa. RESULTS: We obtained complete or partial mitochondrial genomes from 232 historical and modern samples, representing 40 of the 43 currently recognized species of Sciurini. Our phylogenetic analyses-performed with datasets differing on levels of missing data and taxa under distinct analytical methods-strongly support the monophyly of Sciurini and consistently recovered 12 major clades within the tribe. We found evidence that the diversity of Neotropical tree squirrels is underestimated, with at least six lineages that represent taxa to be named or revalidated. Ancestral state reconstructions of number of upper premolars and number of mammae indicated that alternative conditions of both characters must have evolved multiple times throughout the evolutionary history of tree squirrels. CONCLUSIONS: Complete mitogenomes were obtained from museum specimens as old as 120 years, reinforcing the potential of historical samples for phylogenetic inferences of elusive lineages of the tree of life. None of the taxonomic arrangements ever proposed for tree squirrels fully corresponded to our phylogenetic reconstruction, with only a few of the currently recognized genera recovered as monophyletic. By investigating the evolution of two morphological traits widely employed in the taxonomy of the group, we revealed that their homoplastic nature can help explain the incongruence between phylogenetic results and the classification schemes presented so far. Based on our phylogenetic results we suggest a tentative supraspecific taxonomic arrangement for Sciurini, employing 13 generic names used in previous taxonomic classifications.


Assuntos
Variação Genética , Genoma Mitocondrial/genética , Fenótipo , Sciuridae/classificação , Sciuridae/genética , Animais , Filogenia
13.
Mol Ecol ; 29(21): 4074-4090, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32911576

RESUMO

Janzen's influential "mountain passes are higher in the tropics" hypothesis predicts restricted gene flow and genetic isolation among populations spanning elevational gradients in the tropics. Few studies have tested this prediction, and studies that focus on population genetic structure in Southeast Asia are particularly underrepresented in the literature. Here, we test the hypothesis that mountain treeshrews (Tupaia montana) exhibit limited dispersal across their broad elevational range which spans ~2,300 m on two peaks in Kinabalu National Park (KNP) in Borneo: Mt Tambuyukon (MT) and Mt Kinabalu (MK). We sampled 83 individuals across elevations on both peaks and performed population genomics analyses on mitogenomes and single nucleotide polymorphisms from 4,106 ultraconserved element loci. We detected weak genetic structure and infer gene flow both across elevations and between peaks. We found higher genetic differentiation on MT than MK despite its lower elevation and associated environmental variation. This implies that, contrary to our hypothesis, genetic structure in this system is not primarily shaped by elevation. We propose that this pattern may instead be the result of historical processes and limited upslope gene flow on MT. Importantly, our results serve as a foundational estimate of genetic diversity and population structure from which to track potential future effects of climate change on mountain treeshrews in KNP, an important conservation stronghold for the mountain treeshrew and other montane species.


Assuntos
Altitude , Fluxo Gênico , Animais , Bornéu , Estruturas Genéticas , Humanos , Mamíferos
14.
Analyst ; 145(2): 497-506, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31750459

RESUMO

Nosocomial infections are a major concern at the worldwide level. Early and accurate identification of nosocomial pathogens is crucial to provide timely and adequate treatment. A prompt response also prevents the progression of the infection to life-threatening conditions, such as septicemia or generalized bloodstream infection. We have implemented two highly sensitive methodologies using an ultrasensitive photonic biosensor based on a bimodal waveguide interferometer (BiMW) for the fast detection of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), two of the most prevalent bacteria associated with nosocomial infections. For that, we have developed a biofunctionalization strategy based on the use of a PEGylated silane (silane-PEG-COOH) which provides a highly resistant and bacteria-repelling surface, which is crucial to specifically detect each bacterium. Two different biosensor assays have been set under standard buffer conditions: one based on a specific direct immunoassay employing polyclonal antibodies for the detection of P. aeruginosa and another one employing aptamers for the direct detection of MRSA. The biosensor immunoassay for P. aeruginosa is fast (it only takes 12 min) and specific and has experimentally detected concentrations down to 800 cfu mL-1 (cfu: colony forming unit). The second one relies on the use of an aptamer that specifically detects penicillin-binding protein 2a (PBP2a), a protein only expressed in the MRSA mutant, providing a photonic biosensor with the ability to identify the resistant pathogen MRSA and differentiate it from methicillin-susceptible S. aureus (MSSA). Direct, label-free, and selective detection of whole MRSA bacteria has been achieved, making possible the direct detection of also 800 cfu mL-1. According to the signal-to-noise (S/N) ratio of the device, a theoretical limit of detection (LOD) of around 49 and 29 cfu mL-1 was estimated for P. aeruginosa and MRSA, respectively. Both results obtained under standard conditions reveal the great potential this interferometric biosensor device has as a versatile and specific tool for bacterial detection and quantification, providing a rapid method for the identification of nosocomial pathogens within the clinical requirements of sensitivity for the diagnosis of infections.


Assuntos
Técnicas Biossensoriais/métodos , Infecção Hospitalar/diagnóstico , Interferometria/instrumentação , Interferometria/métodos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/diagnóstico , Infecção Hospitalar/microbiologia , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologia
15.
Sensors (Basel) ; 19(15)2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31366087

RESUMO

The baseline of a specific variable defines the average behavior of that variable and it must be built from long data series that represent its spatial and temporal variability. In coastal and marine waters, phytoplankton can produce blooms characterized by a wide range of total cells number or chlorophyll a concentration. Classifying a phytoplankton abundance increase as a bloom depends on the species, the study area and the season. The objective of this study was to define the baseline of satellite absorption coefficients in Todos Santos Bay (Baja California, Mexico) to determine the presence of phytoplankton blooms based on the satellite inherent optical properties index (satellite IOP index). Two field points were selected according to historical bloom reports. To build the baseline, the data of phytoplankton absorption coefficients ( a p h y , G I O P ) and detritus plus colored dissolved organic matter (CDOM) ( a d C D O M , G I O P ) from the generalized inherent optical property (GIOP) satellite model of the NASA moderate resolution imaging spectroradiometer (MODIS-Aqua) sensor was studied for the period 2003 to 2016. Field data taken during a phytoplankton bloom event on June 2017 was used to validate the use of satellite products. The association between field and satellite data had a significant positive correlation. The satellite baseline detected a trend change from high values to low values of the satellite IOP index since 2010. Improved wastewater treatment to waters discharged into the Bay, and increased aquaculture of filter-feeding mollusks could have been the cause. The methodology proposed in this study can be a supplementary tool for permanent in situ monitoring programs. This methodology offers several advantages: A complete spatial coverage of the specific coastal area under study, appropriate temporal resolution and a tool for building an objective baseline to detect deviation from average conditions during phytoplankton bloom events.


Assuntos
Técnicas Biossensoriais , Diatomáceas/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Fitoplâncton/crescimento & desenvolvimento , Clorofila/análise , Eutrofização , Estações do Ano
16.
Biol Lett ; 13(3)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28330975

RESUMO

Many ecological aspects of tool-use in sea otters are similar to those in Indo-Pacific bottlenose dolphins. Within an area, most tool-using dolphins share a single mitochondrial haplotype and are more related to each other than to the population as a whole. We asked whether sea otters in California showed similar genetic patterns by sequencing mitogenomes of 43 otters and genotyping 154 otters at 38 microsatellite loci. There were six variable sites in the mitogenome that yielded three haplotypes, one found in only a single individual. The other two haplotypes contained similar percentages (33 and 36%) of frequent tool-users and a variety of diet types. Microsatellite analyses showed that snail specialists, the diet specialist group that most frequently used tools, were no more related to each other than to the population as a whole. The lack of genetic association among tool-using sea otters compared with dolphins may result from the length of time each species has been using tools. Tool-use in dolphins appears to be a relatively recent innovation (less than 200 years) but sea otters have probably been using tools for many thousands or even millions of years.


Assuntos
Lontras/fisiologia , Comportamento de Utilização de Ferramentas , Animais , California , Dieta/veterinária , Genoma Mitocondrial , Haplótipos , Repetições de Microssatélites , Lontras/genética
17.
Conserv Biol ; 31(5): 1163-1172, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-27859602

RESUMO

The intentional and unintentional movement of plants and animals by humans has transformed ecosystems and landscapes globally. Assessing when and how a species was introduced are central to managing these transformed landscapes, particularly in island environments. In the Gulf of Alaska, there is considerable interest in the history of mammal introductions and rehabilitating Gulf of Alaska island environments by eradicating mammals classified as invasive species. The Arctic ground squirrel (Urocitellus parryii) is of concern because it affects vegetation and seabirds on Gulf of Alaska islands. This animal is assumed to have been introduced by historic settlers; however, ground squirrel remains in the prehistoric archaeological record of Chirikof Island, Alaska, challenge this timeline and suggest they colonized the islands long ago. We used 3 lines of evidence to address this problem: direct radiocarbon dating of archaeological squirrel remains; evidence of prehistoric human use of squirrels; and ancient DNA analysis of dated squirrel remains. Chirikof squirrels dated to at least 2000 years ago, and cut marks on squirrel bones suggested prehistoric use by people. Ancient squirrels also shared a mitochondrial haplotype with modern Chirikof squirrels. These results suggest that squirrels have been on Chirikof longer than previously assumed and that the current population of squirrels is closely related to the ancient population. Thus, it appears ground squirrels are not a recent, human-mediated introduction and may have colonized the island via a natural dispersal event or an ancient human translocation.


Assuntos
Conservação dos Recursos Naturais , DNA Antigo , Espécies Introduzidas , Sciuridae , Alaska , Animais , Arqueologia , Humanos , Ilhas
18.
Gac Med Mex ; 153(3): 385-389, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-28763081

RESUMO

The aim of this study was to analyze Internal Medicine as a subject and its requirement in each of the Universities curriculum in Mexico that offers a degree in General Medicine. By the end of the first quarter of 2014, the research was closed and 81 campuses were studied. This research was quantitative, using an analytical technique, written discourse, exploratory and purposive sampling not random and homogeneous type. The Likert questionnaire was used in this study to analyse the following variables: the record of Internal Medicine as a subject, the burden of credit, and the location of the program. The procedure consisted of three phases. First obtaining an official list of all the Universities in the Mexican Association of Colleges and Schools of Medicine. Second, obtaining an analysis of each of the Universities' curriculums, and lastly gathering each variable of the study. The results of the Universities were 63% were public and 37% private. Internal Medicine as a subject in the curriculum was 37.1%, and 20% of the universities include it for six months and 9% offer it the whole year. However, the undergraduate internship in Internal Medicine offers it 100%. In conclusion, Internal Medicine as a subject could disappear from the curriculum in General Medicine before coming to the undergraduate internship, even though the latter is declared required in hospital shifts.


Assuntos
Currículo , Educação de Graduação em Medicina/organização & administração , Medicina Geral/educação , Medicina Interna/educação , Humanos , Internato e Residência , México , Inquéritos e Questionários , Universidades/estatística & dados numéricos
19.
BMC Evol Biol ; 16: 80, 2016 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-27075887

RESUMO

BACKGROUND: The Indonesian island of Sulawesi has a complex geological history. It is composed of several landmasses that have arrived at a near modern configuration only in the past few million years. It is the largest island in the biodiversity hotspot of Wallacea-an area demarcated by the biogeographic breaks between Wallace's and Lydekker's lines. The mammal fauna of Sulawesi is transitional between Asian and Australian faunas. Sulawesi's three genera of squirrels, all endemic (subfamily Nannosciurinae: Hyosciurus, Rubrisciurus and Prosciurillus), are of Asian origin and have evolved a variety of phenotypes that allow a range of ecological niche specializations. Here we present a molecular phylogeny of this radiation using data from museum specimens. High throughput sequencing technology was used to generate whole mitochondrial genomes and a panel of nuclear ultraconserved elements providing a large genome-wide dataset for inferring phylogenetic relationships. RESULTS: Our analysis confirmed monophyly of the Sulawesi taxa with deep divergences between the three endemic genera, which predate the amalgamation of the current island of Sulawesi. This suggests lineages may have evolved in allopatry after crossing Wallace's line. Nuclear and mitochondrial analyses were largely congruent and well supported, except for the placement of Prosciurillus murinus. Mitochondrial analysis revealed paraphyly for Prosciurillus, with P. murinus between or outside of Hyosciurus and Rubrisciurus, separate from other species of Prosciurillus. A deep but monophyletic history for the four included species of Prosciurillus was recovered with the nuclear data. CONCLUSIONS: The divergence of the Sulawesi squirrels from their closest relatives dated to ~9.7-12.5 million years ago (MYA), pushing back the age estimate of this ancient adaptive radiation prior to the formation of the current conformation of Sulawesi. Generic level diversification took place around 9.7 MYA, opening the possibility that the genera represent allopatric lineages that evolved in isolation in an ancient proto-Sulawesian archipelago. We propose that incongruence between phylogenies based on nuclear and mitochondrial sequences may have resulted from biogeographic discordance, when two allopatric lineages come into secondary contact, with complete replacement of the mitochondria in one species.


Assuntos
Sciuridae/classificação , Sciuridae/genética , Animais , Biodiversidade , Evolução Biológica , Sequência Conservada , Genoma Mitocondrial , Indonésia , Mitocôndrias/genética , Museus , Filogenia , Análise de Sequência de DNA
20.
BMC Genomics ; 17(1): 1013, 2016 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-27938335

RESUMO

BACKGROUND: The African wild dog (Lycaon pictus) is an endangered African canid threatened by severe habitat fragmentation, human-wildlife conflict, and infectious disease. A highly specialized carnivore, it is distinguished by its social structure, dental morphology, absence of dewclaws, and colorful pelage. RESULTS: We sequenced the genomes of two individuals from populations representing two distinct ecological histories (Laikipia County, Kenya and KwaZulu-Natal Province, South Africa). We reconstructed population demographic histories for the two individuals and scanned the genomes for evidence of selection. CONCLUSIONS: We show that the African wild dog has undergone at least two effective population size reductions in the last 1,000,000 years. We found evidence of Lycaon individual-specific regions of low diversity, suggestive of inbreeding or population-specific selection. Further research is needed to clarify whether these population reductions and low diversity regions are characteristic of the species as a whole. We documented positive selection on the Lycaon mitochondrial genome. Finally, we identified several candidate genes (ASIP, MITF, MLPH, PMEL) that may play a role in the characteristic Lycaon pelage.


Assuntos
Animais Selvagens/genética , Canidae/genética , Espécies em Perigo de Extinção , Genoma , Genômica , Animais , Cromossomos , Genética Populacional , Genoma Mitocondrial , Geografia , Polimorfismo de Nucleotídeo Único , Seleção Genética
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