87 resultados para GENETIC CONSERVATION


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Location or stock-specific landing data are necessary to improve management of shark stocks, especially those imperiled by overexploitation as a result of the international shark fin trade. In the current absence of catch monitoring directly at extraction sites, genetic stock identification of fins collected from major market supply chain endpoints offers an overlooked but potentially useful approach for tracing the fins back to their geographical, or stock of, origin. To demonstrate the feasibility of this approach, we used mitochondrial control region (mtCR) sequences to trace the broad geographical origin of 62 Hong Kong market-derived Sphyrna lewini fins. Of these fins 21% were derived from the western Atlantic, where this species is listed as 'Endangered' by the International Union for the Conservation of Nature (IUCN). We also show that S. lewini mtCR sequences are geographically segregated in the western Atlantic (overall ΦST = 0.74, n = 177 sharks), indicating that breeding females either remain close to, or home back to, their natal region for parturition. Mixed stock analysis simulations showed that it is possible to estimate the relative contributions of these mitochondrial stocks to fin mixtures in globally sourced trade hubs. These findings underscore the feasibility of using genetic stock identification to source market-derived shark fins to obtain essential and otherwise unavailable data on exploitation levels, and thus to productively inform stock assessment and management of S. lewini and potentially also of other fished shark species. © Inter-Research 2009.

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Similar to many small, range-restricted elasmobranchs, the Brazilian sharpnose shark (Rhizoprionodon lalandii) is listed as 'data deficient' by the International Union for the Conservation of Nature (IUCN). Data on stock assessment and sustainability are scarce, and there is no information on population structure. This constitutes a management problem because this shark comprises approximately 50% of the catch of small coastal sharks in Brazil. In this study, populations of R. lalandii distributed from the Caribbean to southern Brazil were investigated using sequences from the mitochondrial DNA control region. Analysis of molecular variance revealed strong structuring between population samples from the Caribbean and those from the Brazilian coast (F{cyrillic}ST=0.254, P<0.0001). Significant differences in the rates of genetic diversity between these major areas were also detected. The observed levels of population structuring are likely to be driven by female phylopatry. Therefore, the identification of both mating and nursery areas with parallel ban/restriction of fishing in these areas may be critical for the long-term sustainability of these populations. © 2013 John Wiley & Sons, Ltd.

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Fungi are a diverse group of organisms with an overall global number of 1.5 M up to 3.3 M species on Earth. Besides their ecological roles as decomposers, fungi are important in several aspects of applied research. Here, we review how culture collections may promote the knowledge on diversity, conservation and biotechnological exploitation of fungi. The impact of fungi diversity on biotechnological studies is discussed. We point out the major roles of microbial repositories, including fungal preservation, prospecting, identification, authentication and supply. A survey on the World Data Center for Microorganisms (WDCM) powered by the World Federation for Culture Collections and on the Genetic Heritage Management Council (CGEN) database revealed that 46 Brazilian culture collections registered in these databases are dedicate to preserving fungi. Most of these culture collections are located in the Southeast of Brazil. This scenario also demonstrates that Brazil has many collections focused on fungal strains, but the lack of up-to-date information in WDCM as well as of a solid national platform for culture collections registration do not allow accurate assessment of fungal preservation. © 2013 Elsevier Inc. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Dendrobium is a large genus in the family Orchidaceae that exhibits vast diversity in floral characteristics, which is of considerable importance to orchid breeders, biotechnologists and collectors. Native species have high value as a result of their medicinal properties, while their hybrids are important as ornamental commodities, either as cut flowers or potted plants and are thus veritable industrial crops. Thus, preservation of Dendrobium germplasm is valuable for species conservation, breeding programs and the floriculture industry. Cryopreservation represents the only safe, efficient and cost-effective long-term storage option to facilitate the conservation of genetic resources of plant species. This review highlights 16 years of literature related to the preservation of Dendrobium germplasm and comprises the most comprehensive assessment of thorough studies performed to date, which shows reliable and reproducible results. Air-drying, encapsulation-dehydration, encapsulation-vitrification, vitrification and droplet-vitrification are the current cryopreservation methodologies that have been used to cryopreserve Dendrobium germplasm. Mature seeds, pollen, protoplasts, shoot primordia, protocorms and somatic embryos or protocorm-like bodies (PLBs) have been cryopreserved with different levels of success. Encapsulation-vitrification and encapsulation-dehydration are the most used protocol, while PLBs represent the main explant explored.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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A central question in evolutionary biology is how interactions between organisms and the environment shape genetic differentiation. The pathogen Batrachochytrium dendrobatidis (Bd) has caused variable population declines in the lowland leopard frog (Lithobates yavapaiensis); thus, disease has potentially shaped, or been shaped by, host genetic diversity. Environmental factors can also influence both amphibian immunity and Bd virulence, confounding our ability to assess the genetic effects on disease dynamics. Here, we used genetics, pathogen dynamics, and environmental data to characterize L.yavapaiensis populations, estimate migration, and determine relative contributions of genetic and environmental factors in predicting Bd dynamics. We found that the two uninfected populations belonged to a single genetic deme, whereas each infected population was genetically unique. We detected an outlier locus that deviated from neutral expectations and was significantly correlated with mortality within populations. Across populations, only environmental variables predicted infection intensity, whereas environment and genetics predicted infection prevalence, and genetic diversity alone predicted mortality. At one locality with geothermally elevated water temperatures, migration estimates revealed source-sink dynamics that have likely prevented local adaptation. We conclude that integrating genetic and environmental variation among populations provides a better understanding of Bd spatial epidemiology, generating more effective conservation management strategies for mitigating amphibian declines.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)