Os vírus da hepatite B (HBV), C (HCV) e Delta (HDV) causam grande impacto para a saúde pública mundial. Noventa e duas, oito e quatro amostras para HBsAg, anti-HD e anti-HCV, respectivamente, foram identificadas em indivíduos no Maranhão. Cinquenta amostras positivas para HBV DNA foram classificadas em subgenótipo D4 (42/86%) e A1 (8/14%). Para o HDV, apenas quatro foram classificadas como HDV-8. As amostras positivas para anti-HCV não apresentaram RNA detectável. O HBV-D4 parece ser o principal vírus representante na região estudada. O estudo filogenético sugere que houve a introdução de uma única cepa do subgenótipo D4 no Maranhão, enquanto que para o subgenótipo A1 existiu introdução de diferentes cepas. A confirmação do achado do HDV-8 em coinfecção com HBV- D4 suporta a hipótese de origem desses vírus na África. A ausência de infecção ativa pelo HCV é provavelmente devido uma introdução recente desse vírus e/ou menor frequência de meios de transmissão eficientes. Mais estudos são necessários em regiões onde é desconhecido o perfil de infecção desses vírus. / Hepatitis B (HBV), C (HCV) and Delta (HDV) viruses cause a great universal public health concern. Ninety-two, eight and four positive individuals for HBsAg, anti-HD and anti-HCV were identified, respectively. Fifty samples for HBV were classified in. subgenotype D4 (42/86%) and A1 (8/14%). Concerning HDV, four samples were identified as HDV-8 genotype. Anti-HCV positive samples were negative for RNA. HBV-D4 seems to be the main representative in the studied region. The phylogenetic tree topology suggests there was the introduction of a single strain of D4 subgenotype in Maranhao, whereas subgenotype A1 had several introductions of different strains. The finding of HDV-8 in coinfection with HBV D4 confirms the hypothesis of origin of these viruses in Africa. The low number of HCV infection in this region may be due to the recent introduction of this virus and / or lower frequency of efficient means of transmission. More studies are necessary in other regions where the infection profile of these viruses is indefinite.

As abelhas são insetos da ordem Hymenoptera e taxonomicamente estão reunidas na superfamília Apoidea. Os Meliponini, da subfamília Apinae, são popularmente chamados abelhas indígenas sem ferrão e algumas espécies são essenciais para a polinização de plantas selvagens e lavouras. As abelhas Nannotrigona testaceicornis, utilizadas neste trabalho, são pequenas, possuem o tórax marrom escuro e opaco e não são agressivas. No Brasil, elas são encontradas na Bahia, Espírito Santo, Goiás, Minas Gerais, Rio de Janeiro e São Paulo. Assim como muitas espécies de Hymenoptera, elas também podem nidificar em agregações e analisar a variabilidade genética dentro e entre os agregados foi um dos objetivos deste trabalho, além de avaliar os prováveis múltiplos acasalamentos que parecem ocorrer dentro dessa espécie de meliponíneos. Para tanto, foram coletados indivíduos de ninhos de N. testaceicornis no Campus da USP de Ribeirão Preto (SP), Campinas (SP), Bonfim Paulista (SP), Uberlândia (MG) e Caratinga (MG). 302 indivíduos (operárias) de um total de 32 ninhos foram macerados e tiveram seu DNA extraído. Foram utilizados oito loci microssatélites específicos para o estudo da variabilidade genética e múltiplos acasalamentos. Um total de 38 alelos foi observado. A diversidade genética média entre as agregações foi de 35,4%, a heterozigose média esperada foi de 41,4% e a observada foi de 28,3%. O coeficiente de endogamia (Fis) foi estatisticamente significativo para todas as agregações. Também foram observados desvios no equilíbrio de Hardy-Weinberg para todos os loci analisados. A análise do Fst mostrou diferenciação entre as agregações, porém, apesar da indicação pelo AMOVA de uma discreta estruturação entre as agregações, não foi possível agrupá-las. A partir dos dados obtidos foi possível observar que a diversidade genética nestas agregações está baixa, além disso, os desvios do equilíbrio, o valor significativo do Fis, e a heterozigose observada menor do que a esperada em todos os loci demonstrou a ocorrência de cruzamentos endogâmicos resultando em alto nível de homozigose nesta população. Com relação aos múltiplos acasalamentos, dos 32 ninhos estudados, somente 11 (34,4%) apresentaram uma patrilínea. A presença de alelos nulos, a inclusão acidental de machos na amostra, mudanças recentes de rainhas, operárias de outros ninhos e a contínua conexão entre ninho mãe-filho podem ser possibilidades para estes resultados, entretanto, a frequência de mais de uma patrilínea é muito alta para que a poliandria não seja considerada. / Bees are insects belonging to the Hymenoptera order and to the Apoidea superfamily. The Meliponini, from the subfamily Apinae, are popularly known as stingless bees and some species are essential to the pollination of wild and farming plants. Nannotrigona testaceicornis, studied in this work, are small bees presenting a dark brown and opaque thorax, and non-aggressive behavior. In Brazil, they are found at Bahia, Espírito Santo, Goiás, Minas Gerais, Rio de Janeiro and São Paulo states. As well as many other Hymenoptera species, they can nest on aggregations. To analyze the genetic variability within and among the aggregates was one of the objectives of this work, besides to evaluate the possibility of multiple matings which seem to occur in this species. For this purpose, samples of N. testaceicornis were collected from nests found at University of São Paulo Campus at Ribeirão Preto (SP), Campinas (SP), Bonfim Paulista (SP), Uberlândia (MG) and Caratinga (MG). Three hundred and two individuals (workers) from thirty-two sampled nests had their DNA extracted. Eight specific microsatellite loci were used to study the genetic variability and multiple matings. A total of thirty-eight alleles were observed. The mean genetic diversity among the aggregations was 35.4%, the mean expected heterozygosity was 41.4% and the observed was 28.3%. The inbreeding coefficient (Fis) was statistically significant for all the aggregations. Deviations from Hardy-Weinberg Equilibrium were observed in all studied loci. The Fst analysis showed differentiation among the aggregations but, despite the AMOVA indication of structuring among them, it was not possible to group them. From the obtained data we observed that the genetic diversity of the aggregations is low. The significant Fis value and the observed heterozygosity lower than the expected one in all the studied loci, demonstrated inbreeding events resulting in a high level of homozygosis in this population. In relation to the possibility of multiple mating, from the 32 studied nests, only 11 (34.4%) presented one patriline. The presence of null alleles, the accidental inclusion of males in the sample, recent queen changes, workers drifting among nests, continuing connections between mother and daughter nests or multiple matings might be possibilities for these results. However, the frequency of more than one patriline is very high to not consider the polyandry.

O objetivo da pesquisa foi selecionar isolados de Metarhizium anisopliae patogênicos para cigarrinha-da-raiz, Mahanarva fimbriolata, e caracterizá-los morfológica e geneticamente, por meio de técnicas de análise de DNA (RAPD). A seleção foi feita em laboratório, utilizando ninfas coletadas a campo que foram pulverizadas com o fungo e mantidas nas raízes de mudas de cana-de-açúcar. A mortalidade corrigida, ao quinto dia após a inoculação, variou de 10,5 a 60%. Verificou-se que todos os isolados apresentaram coloração das colônias variando de verde acinzentado ao verde escuro, com crescimento de 28mm para o isolado IBCB-353 à 38mm para o isolado IBCB-348. O comprimento dos conídios não teve influência na patogenicidade e variou de 5,465µm para o isolado IBCB-345 a 7,970µm para o isolado ESALQ 1301 sendo que todos pertencem à subespécie anisopliae. Constatou-se a presença de RNA de fita dupla em onze dos vinte isolados, mas não houve relação entre a presença desta banda e sua patogenicidade para M. fimbriolata. Foi possível separar os isolados em dois grupos (A e B) com 72,5% de similaridade, sendo observada a composição de dois subgrupos (B1 e B2), com 77,5% de similaridade, dentro do grupo B. A alta similaridade entre os dois grupos e dentro de cada um deles, indicou que os isolados pertencem à mesma subespécie, reforçando o que foi concluído com a caracterização morfológica. O método utilizado confirma a grande diversidade genética da espécie M. anisopliae, porém, não reflete sua similaridade de patogenicidade a ninfas de M. fimbriolata, pois os dois isolados mais patogênicos (IBCB-384 e ICBC-348) foram dispostos em grupos diferentes. Não se observou um padrão específico de agrupamento entre isolados oriundos da mesma região ou hospedeiro, ou seja, a diversidade genética parece ser independente do local de origem do fungo, como seria esperado com um patógeno que, em geral, tem revelado alto grau de especialização ao hospedeiro. / This research was carried out to evaluate the pathogenicity of isolates of the entomopatogenic fungus Metarhizium anisopliae against the spittlebug, Mahanarva fimbriolata, and to characterize them morphologically and genetically through RAPD method. The selection was made under laboratory condition, using nymphs collected at field. The fungus was sprayed on the nymphs by a Potter tower (15 pounds/pol2) and then, they were maintained in roots of sugar-cane seedlings. The mortality was evaluated 5 days after the inoculation, ranging from 10.5 to 60%. The colonies’ color varied from grayish green to dark green and the colonies diameter ranged from 28mm (isolate IBCB-353) to 38mm (isolate IBCB-348). The conidia length ranged from 5.465µm for the isolate IBCB-345 to 7.970µm for the isolate ESALQ 1301. With those results it could be concluded that all the studied strains belong to the subspecies anisopliae. The size did not have influence in the pathogenicity of the isolate. It was evidenced presence of double-stranded RNA (virus) in eleven out of the twenty isolates tested, but it did not have relation between the presence of the virus and its pathogenicity for M. fimbriolata. It was possible to separate isolates in two groups (A and B) with 72.5% of similarity, being observed the composition of two sub-groups (B1 and B2), with 77.5% of similarity, inside of group B. The high similarity between the two groups and inside of each one indicated that the isolates belong to the same subspecies, confirming what it was concluded with the morphologic characterization. The used method confirms the great genetic diversity of species M. anisopliae, however, does not reflect its similarity of pathogenicity the nymphs of M. fimbriolata, therefore the two isolated most pathogenic (IBCB-384 and ICBC-348) were located in different fenetic groups. In the present study a specific standard of grouping between isolated deriving of the same region or host was not observed, or either, the genetic diversity seems to be independent on the fungus origin, as it would be expected from a pathogen that, in general, shows high degree of specialization to the host.

The soybean crop is one of the main agricultural crops, with high global economic relevance. The large area under soybean cultivation in Brazil, including the incorporation of new areas in the northern and midwestern regions, mostly under monoculture and non-tillage system, has been affected the prevalence and the intensity of diseases. Among these, one of most prominent is anthracnose, mainly associated with the fungal species Colletotrichum truncatum. Knowledge of the genetic structure of plant pathogen populations can be used to infer their life histories and the evolutionary processes that shape populations in the agroecosystems, which can help to implement effective disease management strategies. However, the genetic structure of C. truncatum populations associated with soybean remains unknown. We collected C. truncatum isolates from 10 sites representing two of main areas of soybean producing in Brazil and used microsatellite markers and whole-genome sequencing to investigate the population biology and evolutionary history of this important pathogen. The multilocus microsatellite typing of 237 isolates revealed high gene and haplotypic diversity within populations, as well low genetic differentiation and sharing of multilocus haplotypes among populations and regions. In addition, three distinct genetic clusters were detected, coexisting in syntopy in the soybean fields, without evidence of admixture between them. Such finding suggesting that Brazilian C. truncatum populations resulted from at least three founder events, which led to three genetic lineages that spread throughout the country. However, the genetic makeup of these lineages remains unknow, and their extreme geographic proximity raises the question of the maintenance of their genetic integrity in the face of admixture. In order to gain insights into the evolutionary history of C. truncatum lineages and to investigate in more details the possibility of a lack of genetic exchanges between them, we employed a population genomic approach. For that, we produced a draft genome sequence of a typical strain of the species associated with soybean anthracnose, which was used as the reference genome. Eighteen representative C. truncatum isolates from the three lineages were submitted to whole genome sequencing, aligned against the reference genome, and variants were identified. Our population genomic analyzes revealed that the genetic structure of C. truncatum pathogen causing soybean anthracnose is formed by three deeply divergent lineages with levels of genetic diversity consistent with repeated introduction events for each lineage. We also found evidence for sexual recombination within and between lineages, with multiples isolates displaying signatures of admixture. Our findings support a scenario in which the three lineages initially diverged in allopatry before experiencing hybridization following secondary contact. Monitoring of the pathogen\'s diversity over time is needed to reveal whether these lineages maintain or fuse, which can impact the disease control methods currently employed. / A soja é uma das principais culturas agrícolas, com alta relevância econômica global. A grande área sob cultivo de soja no Brasil, incluindo a incorporação de novas áreas nas regiões norte e centro-oeste, principalmente sob monocultura e plantio direto, tem afetado a prevalência e a intensidade das doenças. Entre elas, uma das mais proeminentes é a antracnose, principalmente associada à espécie fúngica Colletotrichum truncatum. O conhecimento da estrutura genética das populações de patógenos de plantas pode ser usado para inferir suas histórias de vida e os processos evolutivos que moldam as populações nos agroecossistemas, o que pode ajudar a implementar estratégias eficazes de manejo da doença. No entanto, a estrutura genética das populações de C. truncatum associadas à soja permanece desconhecida. Coletamos isolados de C. truncatum em 10 áreas, representando duas principais regiões produtoras de soja no Brasil. Utilizamos marcadores microssatélites e sequenciamento do genoma completo para investigar a biologia populacional e a história evolutiva desse importante patógeno. A tipagem de microssatélites multilocus de 237 isolados revelou alta diversidade genética e haplotípica nas populações, bem como baixa diferenciação genética e compartilhamento de haplótipos entre populações e regiões. Além disso, foram detectados três grupos genéticos distintos, coexistindo nas mesmas áreas, sem evidência de mistura entre eles. Isto sugere que as populações C. truncatum no Brasil resultaram de pelo menos três eventos fundadores, o que levou á formação das três linhagens genéticas que se espalharam pelo país. No entanto, a composição genética dessas linhagens permanece desconhecida, e sua extrema proximidade geográfica levanta a questão sobre a manutenção de sua integridade genética em face a mistura entre elas. A fim de analisar a história evolutiva das linhagens de C. truncatum e investigar a possibilidade de ausência de trocas genéticas entre elas, empregamos uma abordagem genômica populacional. Para isso, produzimos uma versão preliminar do genoma completo de um isolado típico da espécie, o qual foi utilizado como genoma de referência. Dezoito isolados representativos das três linhagens foram submetidos ao sequenciamento completo, alinhados ao genoma de referência, e variantes foram identificados. Nossas análises genômicas populacionais revelaram que a estrutura genética do patógeno é formada por três linhagens profundamente divergentes, com níveis de diversidade consistentes com repetidos eventos de introdução para cada linhagem. Também encontramos evidências de recombinação sexual dentro e entre linhagens, com múltiplos isolados apresentando assinaturas de mistura. Nossas descobertas sugerem um cenário no qual as três linhagens divergiram inicialmente em alopatria antes de experimentar hibridação, após contato secundário. O monitoramento da diversidade do patógeno ao longo do tempo é necessário para revelar se essas linhagens se mantêm geneticamente separadas ou se fundem, o que pode afetar os métodos de controle da doença atualmente empregados.

[Truncated abstract] An investigation into the causes of heartwood and essential oil content of Australian plantation sandalwood, Santalum album was undertaken. Genetic diversity of 233 S. album, five S. austrocaledonicum and fifteen S. macgregorii trees growing in the Forest Products Commission arboretum, Kununurra WA, was assessed using nuclear and chloroplast RFLPs. Santalum spicatum was chosen as an out-group. Nuclear genetic diversity of the S. album collection was very low, with observed and expected heterozygosity levels of 0.047. This was lower than the results previously reported in the literature for trees in India, however a different technique was used. Based on allelic patterns, the collection was able to be categorised into 19 genotypes; each representing some shared genetic origin. Some groups were highly redundant with 56 trees being represented, while others were populated by just one tree. The essential oil yield and heartwood contents of trees from these genetic groups were compared. Yields were highly variable both within and between groups of trees which share a common genetic history, suggesting a significant environmental component was contributing to the observed phenotype, despite identical soil and climatic conditions. Ancestral lineages were tested using chloroplast RFLPs, although a lack of shared mutations between species made this difficult. Only one S. album tree originating from Timor was resolved using nuclear RFLPs, with the other trees being grouped with material sourced from India. There was no resolution of Indian S. album from Timorese using chloroplast RFLPs, however one S. album tree grown from Indian seed possessed a single unique mutation. The low genetic diversity of the Australian S. album collection is likely to be a combination of incomplete seed sourcing and highly restricted gene flow during the evolution of the species. Combined with information gathered on the phylogeny of the genus by other researchers, S. album is postulated to have originated from an over-sea dispersal out of northern Australia or Papua New Guinea 3 to 5 million years ago. Essential oil yield and composition was assessed for 100 S. album trees growing in the collection, ranging in age from 8 to 17 years. Oil content of heartwood ranged from 30 mg g-1 to 60 mg g-1, and the transition zone 36 mg g-1 to 90 mg g-1. Sapwood contained almost no sesquiterpene oils. Despite the highly variable total oil yields, the chemical profile of the oil did not vary, suggesting there was limited genetic diversity within this region of the genome. Strong, positive correlations existed between v sesquiterpenoids in the essential oil of S. album. ... These represent the first TPS genes to be isolated from sandalwood and will enable further elucidation of oil biosynthesis genes. This thesis compiles a three-pronged approach to understanding the underlying causes of oil yield variation in S. album. As a species for which so little is known, the research presented here provides a major leap forward for tree improvement, breeding and silviculture. Hence the best of Santalum album research is presented.

The aim of the present study was to evaluate the power of discrimination and genetic (diversity) parameters in the Y chromosome extended haploytpe markers in populations of Tanzania for forensic and populations studies. Eleven Y chromosome extended haplotype markers were selected for this study, these includes Minimal haplotypes markers i.e. DYS19, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS389I/II and two additional markers DYS438 and DYS439. Six populations of Tanzania were investigated under this study. These populations were selected based on the language family categories / Niger Congo (Kuria and Sukuma), Nilo Saharan (Luo and Maasai) and Afro Asiatic (Iraqw and Alagwa).

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L’expansion agricole ne cesse d’agir sur la perte d’habitats essentiels et nécessaires au développement des espèces. Bien que plusieurs espèces réussissent à survivre dans ces habitats peu adéquats, la persistance et la santé de plusieurs populations semblent compromises par l’utilisation souvent intensive de polluants chimiques agricoles et de fertilisants. Cette étude a pour but de déterminer l’impact des contaminants et de l’écologie du paysage sur la diversité génétique des populations de ouaouarons retrouvées en milieu agricole. Notre hypothèse de départ stipule qu’une exposition chronique aux polluants agricoles induira des différences génétiques au niveau des populations exposées. Le bassin versant de la rivière Yamaska a été désigné comme site d’étude puisqu’il fait partie de la région agricole la plus importante du Québec et parce qu’on y retrouve un gradient d’utilisation des terres pour l’agriculture (faible, moyen, élevé). Le ouaouaron a été choisi à titre de modèle biologique puisque ses caractéristiques physiologiques et écologiques en font une espèce sentinelle capable de rendre compte de l’état de santé global des écosystèmes. La caractérisation génétique des populations a été effectuée à partir de marqueurs d’AFLP (Amplified Fragment Length Polymorphism). Les résultats montrent que la diversité génétique est liée à la colonisation à partir de l’embouchure de la rivière Yamaska et que quelques populations sont génétiquement différenciées. De plus, nous avons démontré une relation positive entre le nombre de locus polymorphes et l’atrazine, l’indice de contamination et le métolachlore et la concentration en azote ainsi qu’entre l’hétérozygotie attendue et la concentration en phosphate. / Agricultural expansion continues to act on the loss of critical habitats for the development of species and affects the integrity of remaining habitats. Although several species manage to survive in such inadequate ecosystems, persistence and health of many populations seem compromised by the intensive use of pesticides and fertilizers. This study aims at determining the impact of pollutants and landscape ecology on the genetic diversity of bullfrog populations inhabiting an agricultural area. Our hypothesis states that chronic exposure to agricultural pollutants induces genetic differences in exposed populations. The watershed of the Yamaska River was designated as the study site because it is part of the largest agricultural region in Quebec and because the sampling sites represent a gradient of land use for agriculture (low, moderate, high). The bullfrog was chosen as the biological model, since its physiological and ecological characteristics make it a sentinel species, which can reflect the overall health of an ecosystem. Population genetic characterization has been conducted from AFLP (Amplified Fragment Length Polymorphism) markers. The results show that genetic diversity is correlated to colonization from the mouth of the Yamaska River and that some populations are genetically differentiated. Furthermore, we demonstrated a positive relationship between the number of polymorphic loci and the atrazine, the contamination index and the nitrogen concentration as well as between expected heterozygosity and phosphate concentration.