940 resultados para GENETIC CONSERVATION
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[EN] Green turtle hatchlings disperse away from their natal location to spend an early pelagic stage in the ocean, followed by a neritic stage where small juveniles settle in coastal areas. Here, we combined genetic and Lagrangian drifter data to investigate the connectivity between natal and foraging locations; particularly focussing on the evidence for transatlantic transport. Our results supported the general hypothesis that turtles tend to select foraging areas ‘closest-to-home’.
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[EN] Complex population structure has been described for the loggerhead sea turtle (Caretta caretta), revealing lower levels of population genetic structure in nuclear compared to mitochondrial DNA assays. This may result from mating during spatially overlapping breeding migrations, or male-biased dispersal as previously found for the green turtle (Chelonia mydas). To further investigate these multiple possibilities, we carried out a comparative analysis from twelve newly developed microsatellite loci and the mitochondrial DNA control region (~804 bp) in adult females of the Cape Verde Islands (n=158), and Georgia, USA (n=17).
Low genetic diversity in Diplomystes camposensis, an endemic and endangered catfish from South Chile
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Natural populations of fish species in Lake Victoria Region (LVR) have under gone dramatic changes including severe reduction in sizes, division of original stocks into disjunct subunits, and segregation into several isolated population units either within a single water body or even worse into separate waters. In addition, these changes have been either preceded or precipitated by introductions of non-indigenous species that out competed the native forms and in case of closely related species genetically swamped them through hybridisation. The latter is especially the case in Nabugabo lakes. Such events lead to fragmentation of populations, which results in reduction in genetic diversity due to genetic drift, inbreeding and reduced or lack of gene flow among independent units. Such phenomena make the continued existence of fisheries stocks in the wild precarious, more so in the face of the competition from exotic species. Species introductions coupled with growing exploitation pressure of the fisheries of these lakes have put the native stocks at risk. Nabugabo lakes harbor cichlid species that are unique to these lakes more so species of the cichlid complex. In this paper the ecological status and genetic viability of key Nabugabo lakes fish species is examined and management options are discussed.
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Tese de Doutoramento, Biologia (Ecologia Vegetal), 25 de Junho de 2013, Universidade dos Açores.
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Tese de Doutoramento, Biologia (Ecologia Vegetal), 24 de Junho de 2013, Universidade dos Açores.
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Bubo bubo is the largest owl in the world, showing a wide geographical distribution throughout the Palaearctic region. It underwent a demographic decline in many European countries during the last century and was considered “vulnerable” (Annex II of the CITES). Nowadays, it is classified as “Least Concern” according to IUCN. Despite its ecological importance and conservation status, few polymorphic molecular markers are available to study its diversity and population genetics. We report on the isolation and development of 10 new microsatellites for the Eagle owl, B. bubo. All loci (10 tetra-nucleotide) are characterized by high polymorphism levels. Number of alleles ranged from 5 to 13 and expected heterozygosity varied from 0.733 to 0.840. These microsatellites would be very useful to assess the genetic diversity, connectivity patterns and parentage of B. bubo. This information will allow to establish new conservation strategies and improve the management of the species.
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Themarine environment seems, at first sight, to be a homogeneousmediumlacking barriers to species dispersal. Nevertheless, populations of marine species show varying levels of gene flow and population differentiation, so barriers to gene flow can often be detected. Weaimto elucidate the role of oceanographical factors ingenerating connectivity among populations shaping the phylogeographical patterns in the marine realm, which is not only a topic of considerable interest for understanding the evolution ofmarine biodiversity but also formanagement and conservation of marine life. For this proposal,we investigate the genetic structure and connectivity between continental and insular populations ofwhite seabreamin North East Atlantic (NEA) and Mediterranean Sea (MS) aswell as the influence of historical and contemporary factors in this scenario using mitochondrial (cytochrome b) and nuclear (a set of 9 microsatellite) molecular markers. Azores population appeared genetically differentiated in a single cluster using Structure analysis. This result was corroborated by Principal Component Analysis (PCA) and Monmonier algorithm which suggested a boundary to gene flow, isolating this locality. Azorean population also shows the highest significant values of FST and genetic distances for both molecular markers (microsatellites and mtDNA). We suggest that the breakdown of effective genetic exchange between Azores and the others' samples could be explained simultaneously by hydrographic (deep water) and hydrodynamic (isolating current regimes) factors acting as barriers to the free dispersal of white seabream(adults and larvae) and by historical factors which could be favoured for the survival of Azorean white seabream population at the last glaciation. Mediterranean islands show similar genetic diversity to the neighbouring continental samples and nonsignificant genetic differences. Proximity to continental coasts and the current system could promote an optimal larval dispersion among Mediterranean islands (Mallorca and Castellamare) and coasts with high gene flow.
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Forest trees, like oaks, rely on high levels of genetic variation to adapt to varying environmental conditions. Thus, genetic variation and its distribution are important for the long-term survival and adaptability of oak populations. Climate change is projected to lead to increased drought and fire events as well as a northward migration of tree species, including oaks. Additionally, decline in oak regeneration has become increasingly concerning since it may lead to decreased gene flow and increased inbreeding levels. This will in turn lead to lowered levels of genetic diversity, negatively affecting the growth and survival of populations. At the same time, populations at the species’ distribution edge, like those in this study, could possess important stores of genetic diversity and adaptive potential, while also being vulnerable to climatic or anthropogenic changes. A survey of the level and distribution of genetic variation and identification of potentially adaptive genes is needed since adaptive genetic variation is essential for their long-term survival. Oaks possess a remarkable characteristic in that they maintain their species identity and specific environmental adaptations despite their propensity to hybridize. Thus, in the face of interspecific gene flow, some areas of the genome remain differentiated due to selection. This characteristic allows the study of local environmental adaptation through genetic variation analyses. Furthermore, using genic markers with known putative functions makes it possible to link those differentiated markers to potential adaptive traits (e.g., flowering time, drought stress tolerance). Demographic processes like gene flow and genetic drift also play an important role in how genes (including adaptive genes) are maintained or spread. These processes are influenced by disturbances, both natural and anthropogenic. An examination of how genetic variation is geographically distributed can display how these genetic processes and geographical disturbances influence genetic variation patterns. For example, the spatial clustering of closely related trees could promote inbreeding with associated negative effects (inbreeding depression), if gene flow is limited. In turn this can have negative consequences for a species’ ability to adapt to changing environmental conditions. In contrast, interspecific hybridization may also allow the transfer of genes between species that increase their adaptive potential in a changing environment. I have studied the ecologically divergent, interfertile red oaks, Quercus rubra and Q. ellipsoidalis, to identify genes with potential roles in adaptation to abiotic stress through traits such as drought tolerance and flowering time, and to assess the level and distribution of genetic variation. I found evidence for moderate gene flow between the two species and low interspecific genetic differences at most genetic markers (Lind and Gailing 2013). However, the screening of genic markers with potential roles in phenology and drought tolerance led to the identification of a CONSTANS-like (COL) gene, a candidate gene for flowering time and growth. This marker, located in the coding region of the gene, was highly differentiated between the two species in multiple geographical areas, despite interspecific gene flow, and may play a role in reproductive isolation and adaptive divergence between the two species (Lind-Riehl et al. 2014). Since climate change could result in a northward migration of trees species like oaks, this gene could be important in maintaining species identity despite increased contact zones between species (e.g., increased gene flow). Finally I examined differences in spatial genetic structure (SGS) and genetic variation between species and populations subjected to different management strategies and natural disturbances. Diverse management activities combined with various natural disturbances as well as species specific life history traits influenced SGS patterns and inbreeding levels (Lind-Riehl and Gailing submitted).
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Rare plant conservation efforts must utilize current genetic methods to ensure the evolutionary potential of populations is preserved. One such effort involves the Key Tree Cactus, Pilosocereus robinii, which is an endangered columnar cactus native to the Florida Keys. The populations have precipitously declined over the past decade because of habitat loss and increasing soil salinity from rising sea levels and storm surge. Next-generation DNA sequencing was used to assess the genetic structure of the populations. Twenty individuals representative of both wild and extirpated cacti were chosen for Restriction Site Associated DNA (RAD) analysis. Samples processed using the HindIII and NotIII restriction enzymes produced 82,382,440 high quality reads used for genetic mapping, from which 5,265 Single Nucleotide Polymorphisms (SNPs) were discovered. The analysis revealed that the Keys’ populations are closely related with little population differentiation. In addition, the populations display evidence of inbreeding and low genetic diversity.
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As key prey, the wild rabbit downsize constitutes a major drawback on the endangered Iberian lynx (Lynx pardinus) re-introduction in the Iberia. Several captive breeding units mostly located in Alentejo, endeavour the wild rabbit repopulation of depleted areas assigned for the lynx re-introduction. Here we report an RHDV2 outbreak that occurred in early 2016 in a wild rabbit captive breeding unit located in Barrancos municipality. The estimated mortality rate between March and April 2016 was approximately 8.67%. Anatomopathologic examination was carried out for 13 victimized rabbits. Molecular characterization was based on the complete vp60 capsid gene. The 13 rabbit carcasses investigated showed typical macroscopic RHD lesions testing positive to RHDV2- RNA. Comparison of the vp60 nucleotide sequences obtained from two specimens with others publically available disclosed similarities below 98.22% with RHDV2 strains originated in the Iberia and Azores and revealed that the two identical strains from Barrancos-2016 contain six unique single synonymous nucleotide polymorphisms. In the phylogenetic analysis performed, the Barrancos-2016 strains clustered apart from other known strains, meaning they may represent new evolutionary RHDV2 lineages. No clear epidemiological link could be traced for this outbreak where the mortalities were lower compared with previous years. Yet, network analysis suggested a possible connection between the missing intermediates from which the strains from Barrancos 2013, 2014 and 2016 have derived. It is therefore possible that RHDV2 has circulated endemically in the region since 2012, with periodic epizootic occurrences. Still, six years after its emergence in wild rabbits, RHDV2 continues to pose difficulties to the establishment of natural wild rabbit populations that are crucial for the self-sustainability of the local ecosystems.
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The collection and conservation of the Cucurbita genus in Brazil happened in so dispersed institutions, an assessment of the storage conditions and the genetic diversity is needed, making it possible to identify new priorities for the genus. This work constitutes diagnosis of geographical distribution, storage conditions in situ and ex situ and on genetic diversity of the Cucurbita genus in Brazil. Research was done in herbariums, databases, literature and in situ (expeditions to rural areas and (markets) to map the areas of occurrence of the species. During these expeditions, questionnaires were applied to obtain information about the property and genus Cucurbita. Questionnaires were sent to 173 Brazilian institutions regarding the preservation conditions ex situ. A genetic variability of the Cucurbita genus was found in traditional Brazilian agriculture. Collections must be prioritized in the northern and southern regions (all states); the southeastern region, all states, except Minas Gerais; central-west, in Mato Grosso do Sul and Mato Grosso; the northeastern region, the states of Alagoas, Maranhão, Paraíba, Pernambuco, Piauí and Sergipe. Currently 5.545 entries are being conserved in the Germplasm banks, however, C. pepo, C. ficifolia, C. argyrosperma and wild species are poorly represented. The characterization level of conserved entries is low in the ex situcollections. Participative research projects must be financed as a way to stimulate the farmers to continue planting their local varieties. A coleta e conservação do gênero Cucurbita no Brasil aconteceu de forma dispersa pelas instituições, sendo necessário um diagnóstico sobre as condições de conservação e sobre a diversidade genética, tornando possível identificar novas prioridades para o gênero. Este trabalho realizou diagnóstico sobre distribuição geográfica, condições de conservação in situ e ex situ e sobre diversidade genética do gênro Cucurbita no Brasil. Para mapear as áreas de ocorrência das espécies, foram realizados levantamentos de informações em herbários, banco de dados, literatura e levantamentos in situ (expedições para áreas rurais, feiras livres e CEASAs). Nessas expedições foram aplicados questionários, buscando informações sobre a propriedade e o gênero Cucurbita. Em relação as condições de conservação ex situ, foram enviados questionários para 173 instituições brasileiras. Foi constatado que existe variabilidade genética do gênero Cucurbita na agricultura tradicional brasileira. Devem ser priorizadas coletas nas regiões Norte e Sul (todos os estados); região Sudeste, todos os estados, exceto Minas Gerais; região Centro-Oeste, no Mato Grosso do Sul e Mato Grosso; região Nordeste, os estados de Alagoas, Maranhão, Paraíba, Pernambuco, Piauí e Sergipe. Atualmente estão sendo conservados nos Bancos de Germoplasma 5.545 acessos, no entanto C. pepo, C ficifolia, C. argyrosperma e espécies silvestres estão pouco representadas. É baixa a taxa de caracterização dos acessos conservados nas coleções ex situ. Devem ser financiados projetos de pesquisa participativa como uma forma de estimular e dar condições aos agricultores de continuarem cultivado suas variedades locais.
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The collection and conservation of the Cucurbita genus in Brazil happened in so dispersed institutions, an assessment of the storage conditions and the genetic diversity is needed, making it possible to identify new priorities for the genus. This work constitutes diagnosis of geographical distribution, storage conditions in situ and ex situ and on genetic diversity of the Cucurbita genus in Brazil. Research was done in herbariums, databases, literature and in situ (expeditions to rural areas and (markets) to map the areas of occurrence of the species. During these expeditions, questionnaires were applied to obtain information about the property and genus Cucurbita. Questionnaires were sent to 173 Brazilian institutions regarding the preservation conditions ex situ. A genetic variability of the Cucurbita genus was found in traditional Brazilian agriculture. Collections must be prioritized in the northern and southern regions (all states); the southeastern region, all states, except Minas Gerais; central-west, in Mato Grosso do Sul and Mato Grosso; the northeastern region, the states of Alagoas, Maranhão, Paraíba, Pernambuco, Piauí and Sergipe. Currently 5.545 entries are being conserved in the Germplasm banks, however, C. pepo, C. ficifolia, C. argyrosperma and wild species are poorly represented. The characterization level of conserved entries is low in the ex situcollections. Participative research projects must be financed as a way to stimulate the farmers to continue planting their local varieties. A coleta e conservação do gênero Cucurbita no Brasil aconteceu de forma dispersa pelas instituições, sendo necessário um diagnóstico sobre as condições de conservação e sobre a diversidade genética, tornando possível identificar novas prioridades para o gênero. Este trabalho realizou diagnóstico sobre distribuição geográfica, condições de conservação in situ e ex situ e sobre diversidade genética do gênro Cucurbita no Brasil. Para mapear as áreas de ocorrência das espécies, foram realizados levantamentos de informações em herbários, banco de dados, literatura e levantamentos in situ (expedições para áreas rurais, feiras livres e CEASAs). Nessas expedições foram aplicados questionários, buscando informações sobre a propriedade e o gênero Cucurbita. Em relação as condições de conservação ex situ, foram enviados questionários para 173 instituições brasileiras. Foi constatado que existe variabilidade genética do gênero Cucurbita na agricultura tradicional brasileira. Devem ser priorizadas coletas nas regiões Norte e Sul (todos os estados); região Sudeste, todos os estados, exceto Minas Gerais; região Centro-Oeste, no Mato Grosso do Sul e Mato Grosso; região Nordeste, os estados de Alagoas, Maranhão, Paraíba, Pernambuco, Piauí e Sergipe. Atualmente estão sendo conservados nos Bancos de Germoplasma 5.545 acessos, no entanto C. pepo, C ficifolia, C. argyrosperma e espécies silvestres estão pouco representadas. É baixa a taxa de caracterização dos acessos conservados nas coleções ex situ. Devem ser financiados projetos de pesquisa participativa como uma forma de estimular e dar condições aos agricultores de continuarem cultivado suas variedades locais.
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Abstract. The aim of the study was to know the genetic characteristic and polymorphysm of Indonesian local ducks including Magelang, Tegal, Mojosari, Bali and Alabio duck based on Single Nucleotide Polymorphism (SNP) analysis in D-loop region mtDNA. The long term aim was to set the spesific genetic marker based on SNP D-loop region mtDNA which could differentiate local ducks in Indonesia. In the future, it could be used as selection tool for local duck conservation, and refinement strategy as well as the improvement of genetic quality by utilizing the available native duck germplasm. There were 20 ducks for each duck population and were taken 3 ml of its blood as sample. DNA Isolation Kit high pure PCR template preparation (Geneaid) was uded for Genome DNA isolation. Amplification with PCR technique used primer DL-AnasPF (L56) as forward and DL-AnasPR (H773) as reverse. Next, PCR product or amplicon were sequenced. Sequence result were analyzed with SNP technique and observed the similarity and difference of its nucleotide sequence between individual and population. The result of the study showed that genome DNA from local duck in Indonesia was successfully isolated. DNA fragment of 718 bp was amplified with primer pair of DL-AnasPF and DL-AnasPR. Nucleotide sequence was 469 nt and analyzed with SNP technique. It was compared with standard nucleotide sequence of Anas platyrhynchos (HM010684.1) in Gen Bank. The result of nucleotide sequence similarity percentage was 99.68±0.56%. Single Nucleotide Polymorphism D-loop region mtDNA Indonesian local duck was 0.32±0.56%.  Some SNP was found in Magelang duck C (Klawu blorok), F (Cemani black), G (Gambiran), H (Jarakan kalung), I (Jowo plain) and K (Plain white) also Tegal duck 8, 1, 2, 5, 2, 8 and 2 SNP respectively. It could be concluded that polymorphic genetic characteristic similarity were existed in Indonesia local duck populations which was shown by its big standard deviation SNP in D-loop region mtDNA. Magelang duck with different feather color relatively more polymorphic to another local duck in Indonesia. Single Nucleotide Polymorphism which was achieved could be used as genetic marker that differentiate genetic characteristic of Indonesian local ducks.Key words: genetic characteristic, local duck, Single Nucleotide Polymorphism (SNP), D-loop mtDNAAbstrak. Penelitian ini bertujuan untuk mengetahui karakteristik genetik dan polimorfisme itik lokal Indonesia yaitu itik Magelang, Tegal, Mojosari, Bali dan Alabio berdasarkan analisis Single Nucleotide Polymorphism (SNP) daerah D-loop mtDNA. Tujuan jangka panjangnya adalah menetapkan marker atau penanda genetik berdasarkan SNP daerah D-loop mtDNA spesifik yang dapat membedakan itik-itik lokal yang ada di Indonesia. Selanjutnya digunakan sebagai alat bantu seleksi untuk konservasi, pembibitan dan pengembangbiakan itik lokal. Populasi masing-masing jenis itik lokal yang digunakan sebanyak 20 ekor untuk diambil 3 ml sampel darahnya. Isolasi DNA genom menggunakan DNA Isolation Kithigh pure PCR template preparation (Geneaid). Amplifikasi dengan teknik PCR menggunakan pasangan primer DL-AnasPF (L56) sebagai forward dan DL-AnasPR (H773) sebagai reverse. Produk PCR atau amplikon yang diperoleh disekuensing. Hasil sekuensing dianalisis dengan teknik SNP dan diamati kesamaan dan perbedaan urutan nukleotida antar individu itik dan antar populasi.  Hasil penelitian menunjukkan bahwa DNA genom dari itik lokal di Indonesia berhasil diisolasi. Amplifikasi dengan teknik PCR berhasil memperoleh fragmen berukuran 718 bp. Urutan nukleotida hasil sekuensing sebesar 469 nt dianalisis dengan teknik SNP dan dibandingkan dengan urutan nukleotida standar dari itik Anas platyrhynchos (HM010684.1) yang ada di Gen Bank, diperoleh persentase kesamaan urutan nukleotid sebesar 99,68±0,56%. Single Nucleotide Polymorphism daerah D-loop mtDNA pada itik lokal di Indonesia sebesar 0,32±0,56%. Sejumlah SNP ditemukan pada itik Magelang C (Klawu blorok), F (Hitam cemani), G (Gambiran), H (Jarakan kalung), I (Jowo polos) dan K (Putih polos) serta itik Tegal masing-masing 8, 1, 2, 5, 2, 8 serta 2 SNP. Kesimpulan dari penelitian ini adalah terdapat karakteristik genetik yang polimorfik pada populasi itik lokal di Indonesia, ditunjukkan dengan adanya simpang baku SNP pada daerah D-loop mtDNA yang relatif besar. Itik Magelang dengan warna bulu yang berbeda relatif lebih polimorfik dibandingkan dengan itik lokal lainnya di Indonesia. Single Nucleotide Polymorphism yang diperoleh dapat digunakan sebagai penanda genetik yang dapat membedakan karakteristik genetik yang dimiliki oleh itik lokal di Indonesia.Kata kunci: karakteristik genetik, itik lokal, Single NucleotidePolymorphism (SNP), D-loop mtDNA