RESUMO
Extensive livestock production and urbanization entail modifications of natural landscapes, including installation of fences, development of agriculture, urbanization of natural areas, and construction of roads and infrastructure that, together, impact native fauna. Here, we evaluate the diversity and genetic structure of endemic guanacos (Lama guanicoe) of the Monte and Patagonian Steppe of central Argentina, which have been reduced and displaced by sheep ranching and other impacts of human activities. Analyses of genetic variation of microsatellite loci and d-loop revealed high levels of genetic variation and latitudinal segregation of mitochondrial haplotypes. There were indications of at least two historical populations in the Monte and the Patagonian Steppe based on shared haplotypes and shared demographic history among localities. Currently, guanacos are structured into three groups that were probably reconnected relatively recently, possibly facilitated by a reduction of sheep and livestock in recent decades and a recovery of the guanaco populations. These results provide evidence of the genetic effects of livestock activity and urbanization on wild herbivore populations, which were possibly exacerbated by an arid environment with limited productive areas. The results highlight the importance of enacting conservation management plans to ensure the persistence of ancestral and ecologically functional populations of guanacos.
RESUMO
The domestication of wild vicuña and guanaco by early pre-Inca cultures is an iconic example of wildlife management and domestication in the Americas. Although domestic llamas and alpacas were clearly selected for key, yet distinct, phenotypic traits, the relative patterns and direction of selection and domestication have not been confirmed using genetic approaches. However, the detailed archaeological records from the region suggest that domestication was a process carried out under significant control and planning, which would have facilitated coordinated and thus extremely effective selective pressure to achieve and maintain desired phenotypic traits. Here we link patterns of sequence variation in two well-characterised genes coding for colour variation in vertebrates and interpret the results in the context of domestication in guanacos and vicuñas. We hypothesise that colour variation in wild populations of guanacos and vicunas were strongly selected against. In contrast, variation in coat colour variation in alpaca was strongly selected for and became rapidly fixed in alpacas. In contrast, coat colour variants in llamas were of less economic value, and thus were under less selective pressure. We report for the first time the full sequence of MC1R and 3 exons of ASIP in 171 wild specimens from throughout their distribution and which represented a range of commonly observed colour patterns. We found a significant difference in the number of non-synonymous substitutions, but not synonymous substitutions among wild and domestics species. The genetic variation in MC1R and ASIP did not differentiate alpaca from llama due to the high degree of reciprocal introgression, but the combination of 11 substitutions are sufficient to distinguish domestic from wild animals. Although there is gene flow among domestic and wild species, most of the non-synonymous variation in MC1R and ASIP was not observed in wild species, presumably because these substitutions and the associated colour phenotypes are not effectively transmitted back into wild populations. Therefore, this set of substitutions unequivocally differentiates wild from domestic animals, which will have important practical application in forensic cases involving the poaching of wild vicuñas and guanacos. These markers will also assist in identifying and studying archaeological remains pre- and post-domestication.
RESUMO
Fifteen guanacos were introduced to Staats Island in the Falklands/Malvinas archipelago from Patagonia in the 1930s. Twenty five years later, the population was culled from 300 to 10-20 individuals, but quickly rebounded to a population of almost 400 animals that today retain the genetic signature of the founding event and later bottleneck. The goals of this study were to (i) make a genetic assessment of this island population through comparisons with mainland populations and simulations, and (ii) assess the likely source-population of the introduced guanacos. Genetic variation was estimated from 513 bp of mitochondrial DNA sequence and 15 microsatellite loci among 154 guanacos collected from eight localities, including the adjacent mainland and the islands of Tierra del Fuego and Staats Island. Of the 23 haplotypes observed among our samples, the Staats Island population only contained three haplotypes, all of which were shared with the coastal Monte Leon population in southern Patagonia. Mitochondrial DNA and microsatellite variations on Staats Island were comparable to most mainland populations and greater than those observed on Tierra del Fuego. Patterns of genetic structure suggest that the Staats Island guanaco population was founded with animals from southern Patagonia (as opposed to northern Patagonia or Tierra del Fuego), but that effective reductions in population size lasted only a few generations and that surviving animals were a random sample of the pre-bottleneck genetic variation.
Assuntos
Camelídeos Americanos/genética , Conservação dos Recursos Naturais , Efeito Fundador , Variação Genética , Ilhas , Animais , DNA Mitocondrial/genética , Feminino , Endogamia , Masculino , Repetições de Microssatélites/genética , Modelos GenéticosRESUMO
A comprehensive study of the phylogeography and population genetics of the largest wild artiodactyl in the arid and cold-temperate South American environments, the guanaco (Lama guanicoe) was conducted. Patterns of molecular genetic structure were described using 514 bp of mtDNA sequence and 14 biparentally inherited microsatellite markers from 314 samples. These individuals originated from 17 localities throughout the current distribution across Peru, Bolivia, Argentina and Chile. This confirmed well-defined genetic differentiation and subspecies designation of populations geographically separated to the northwest (L. g. cacsilensis) and southeast (L. g. guanicoe) of the central Andes plateau. However, these populations are not completely isolated, as shown by admixture prevalent throughout a limited contact zone, and a strong signal of expansion from north to south in the beginning of the Holocene. Microsatellite analyses differentiated three northwestern and 4-5 southeastern populations, suggesting patterns of genetic contact among these populations. Possible genetic refuges were identified, as were source-sink patterns of gene flow at historical and recent time scales. Conservation and management of guanaco should be implemented with an understanding of these local population dynamics while also considering the preservation of broader adaptive variation and evolutionary processes.
Assuntos
Camelídeos Americanos/genética , Fluxo Gênico , Genética Populacional , Filogeografia , Animais , DNA Mitocondrial/genética , Variação Genética , Repetições de Microssatélites , Dinâmica Populacional , Análise de Sequência de DNA , América do SulRESUMO
A small, new species of gerbil rodents of the genus Eligmodontia from the southwestern dunes of the Atacama Desert in northern Chile is described; the genus had not been reported for this western lowland region. Our description is based on cytogenetic and molecular data, as well as cranial and external morphology. In order to support this hypothesis, we studied 27 specimens captured in Playa Los Choros (Coquimbo) and Copiapó (Atacama), comparing them with samples of all the extant species of the genus. Nineteen individuals consistently showed 2N=50, FN=48, with telocentric chromosomes and G-bands identical to those of the geographically northeastern E. hirtipes; these two groups were geographically separated by E. puerulus (2N = 34, FN = 48). The phylogenetic analysis of 56 Eligmodontia cytochrome-b gene sequences yielded a maximum-likelihood phylogenetic tree where the new species formed a divergent and well-supported clade within the genus, which was also confirmed by unweighted parsimony, minimum evolution, and Bayesian analyses. The new species has K2P genetic distances of 12.8% from the geographically distant E. hirtipes, and 10.3% from E. puerulus. Axes 1 and 2 of Principal Component Analysis based on 12 body and skull measurements clearly separated the new species, the latter having a smaller head+body length (70.6 +/- 3.4 mm, n = 17) and lower weight (11.9 +/- 1.9 g, n = 20). We provide strong evidence to recognize a distinct new western lineage within Eligmodontia genus, Eligmodontia dunaris sp. nov., for which we give a complete taxonomic description and a hypothetical biogeographic scenario. The new species should be considered endangered, due to its level of endemism, its low population numbers (which can be occasionally increased after a blooming desert) and its fragile dry habitat patchily distributed near the Atacama Desert.
Assuntos
Arvicolinae/classificação , Animais , Arvicolinae/anatomia & histologia , Arvicolinae/genética , Chile , Citocromos b/genética , Variação Genética , Cariótipo , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
Guanaco (Lama guanicoe) is a protected and widely distributed ungulate in South America. A poacher, after killing guanacos in Valle Chacabuco, Chilean Patagonia, transported and stored the meat. Samples were retrieved by local police but the suspect argued that the meat was from a horse. Mitochondrial cytochrome b gene (774 pb), 15 loci microsatellites, and SRY gene were used to identify the species, number of animals and their population origin, and the sex of the animals, respectively. Analysis revealed that the samples came from a female (absence of SRY gene) Patagonian guanaco (assignment probability between 0.0075 and 0.0282), and clearly distinguishing it from sympatric ungulates (E-value = 0). Based on the evidence obtained in the field in addition to forensic data, the suspect was convicted of poaching and illegally carrying fire arms. This is the first report of molecular tools being used in forensic investigations of Chilean wildlife indicating its promising future application in guanaco management and conservation.
Assuntos
Camelídeos Americanos/genética , Conservação dos Recursos Naturais/legislação & jurisprudência , Impressões Digitais de DNA/métodos , Animais , Chile , Citocromos b/genética , Primers do DNA , DNA Mitocondrial/análise , Feminino , Genes sry , Repetições de Microssatélites , Reação em Cadeia da Polimerase , Processos de Determinação Sexual , Especificidade da EspécieRESUMO
Various extracts of the aerial parts of Barkleyanthus salicifolius (Asteraceae) and Penstemon gentianoides (Scrophulariaceae) have been used in folk medicine to treat many ailments, particularly inflammation and migraine. Neither the bioactive components responsible nor the mechanisms involved have been evaluated. Here are reported antioxidant activities of their methanol, dichloromethane, and ethyl acetate extracts. Samples were evaluated for oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, and inhibition of the formation of thiobarbituric acid reactive species (TBARS), a measure of lipid peroxidation. Antioxidant activities were strongly correlated with total polyphenol content. The most active extracts from P. gentianoides in scavenging DPPH radicals and inhibiting TBARS formation were the methanol extract (A) and a further ethyl acetate extract of this (E). Partition E was further divided into eight fractions, and both E and the fractions were compared for activity against butylated hydroxytoluene, quercetin, and tocopherol. Partition E and the most active fractions, 5 and 6, were found to have I(50) values of 14.1, 38.6, and 41.8 ppm, respectively, against DPPH and 18.5, 26.0, and 12.7 ppm, respectively, against TBARS formation. Consistent with this finding, partition E and fractions 4-6 had the greatest ORAC and FRAP values. These results show that these plants could be useful antioxidant sources.
Assuntos
Antioxidantes/análise , Asteraceae/química , Extratos Vegetais/química , Plantago/química , Antioxidantes/farmacologia , Compostos de Bifenilo , Compostos Férricos/química , Flavonoides/análise , Oxirredução , Fenóis/análise , Picratos/química , Extratos Vegetais/farmacologia , Polifenóis , Espécies Reativas de Oxigênio/química , Substâncias Reativas com Ácido Tiobarbitúrico/análiseRESUMO
The methanol extract from the bark of Yucca periculosa F. Baker afforded 4,4'-dihydroxstilbene, resveratrol and 3,3',5,5'-tetrahydroxy-4-methoxystilbene and had growth regulatory activity against the Fall Army worm (Spodoptera frugiperda J.E. Smith, Lepidoptera:Noctuidae) an insect pest of corn. The most active compound was 3,3',5,5'-tetrahydroxy-4-methoxystilbene which had significant effects at 3 microg/g in diets. In addition to the inhibitory activity on bleaching of crocin induced by alkoxyl radicals, these compounds also demonstrated scavenging properties toward 2,2-diphenyl-1-picrylhydrazyl in TLC autographic and spectrophotometric assays. Our results indicate that these compounds could be involved in interference of sclerotization and moulting. These compounds appear to have selective effects on the pre-emergence metabolism of the insect. The results were fully comparable to known natural insect growth inhibitors such as gedunin and Cedrela extracts and have had a possible role as natural insecticidal agents.
Assuntos
Antioxidantes/farmacologia , Lepidópteros/crescimento & desenvolvimento , Controle Biológico de Vetores , Extratos Vegetais/química , Spodoptera/crescimento & desenvolvimento , Estilbenos/farmacologia , Yucca/química , Animais , Antioxidantes/isolamento & purificação , Azadirachta/química , Bioensaio/métodos , Compostos de Bifenilo , Carotenoides/química , Cedrela/toxicidade , Relação Dose-Resposta a Droga , Radicais Livres/antagonistas & inibidores , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Lepidópteros/fisiologia , Limoninas/farmacologia , Picratos/antagonistas & inibidores , Casca de Planta/química , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Spodoptera/fisiologia , Estilbenos/química , Estilbenos/isolamento & purificaçãoRESUMO
Los reportes iniciales sobre cirugía video laparoscópica son excitantes, pero la experiencia universal aún es pequeña para tener una conclusión definitiva, específicamente en el tratamiento del cáncer. Todavía existe gran controversia, aún no resuelta. Sin embargo, algunas suposiciones iniciales, específicamente relacionadas con la visión permitida por el laparoscopio, la cual podría hacer la disección y exposición mesentérica más difícil, fueron comprobadas como incorrectas. Los especímenes quirúrgicos resecados por laparoscopía son similares, la disección ganglionar y los bordes quirúrgicos son semejantes a los obtenidos por cirugía convencional. La exposición y ligadura de los vasos sanguíneos no constituye ningún problema. El equipo óptico y quirúrgico, ha sido mejorado con tal rapidez, que día a día tenemos uno nuevo, y la cirugía puede realizarse con más confianza. La Cirugía colorrectal realizada por laparoscopia tiene las siguientes ventajas. 1. Dolor posoperatorio, íleo, estancia hospitalaria y convalescencia son menores. 2. Retorno rápido a las actividades normales. 3. Trauma abdominal e incidencia de hernia incisional postoperatoria son más bajas y los resultados estéticos son mejores. Por otro lado las desventajas son: 1. Tiempo intraoperatorio mayor. 2. Hay algunas dificultades para extraer las piezas quirúrgicas. (AU)
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Cirurgia Colorretal , Laparoscopia/métodos , Neoplasias Colorretais/terapia , Doenças do Colo/terapia , Doenças Retais/terapia , Cuidados Pré-Operatórios , Colostomia , Complicações Intraoperatórias , Complicações Pós-Operatórias , Tempo de Internação , Anastomose Cirúrgica , NecroseRESUMO
Los reportes iniciales sobre cirugía video laparoscópica son excitantes, pero la experiencia universal aún es pequeña para tener una conclusión definitiva, específicamente en el tratamiento del cáncer. Todavía existe gran controversia, aún no resuelta. Sin embargo, algunas suposiciones iniciales, específicamente relacionadas con la visión permitida por el laparoscopio, la cual podría hacer la disección y exposición mesentérica más difícil, fueron comprobadas como incorrectas. Los especímenes quirúrgicos resecados por laparoscopía son similares, la disección ganglionar y los bordes quirúrgicos son semejantes a los obtenidos por cirugía convencional. La exposición y ligadura de los vasos sanguíneos no constituye ningún problema. El equipo óptico y quirúrgico, ha sido mejorado con tal rapidez, que día a día tenemos uno nuevo, y la cirugía puede realizarse con más confianza. La Cirugía colorrectal realizada por laparoscopia tiene las siguientes ventajas. 1. Dolor posoperatorio, íleo, estancia hospitalaria y convalescencia son menores. 2. Retorno rápido a las actividades normales. 3. Trauma abdominal e incidencia de hernia incisional postoperatoria son más bajas y los resultados estéticos son mejores. Por otro lado las desventajas son: 1. Tiempo intraoperatorio mayor. 2. Hay algunas dificultades para extraer las piezas quirúrgicas.