Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 156-158).

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Submitted by Amanda Silva (amanda.osilva2@ufpe.br) on 2015-03-05T13:59:07Z No. of bitstreams: 2 TESE Fábia de Oliveira Luna.pdf: 6070926 bytes, checksum: 5c0233b17f6af6c3a2f420f1d6eb3248 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-05T13:59:07Z (GMT). No. of bitstreams: 2 TESE Fábia de Oliveira Luna.pdf: 6070926 bytes, checksum: 5c0233b17f6af6c3a2f420f1d6eb3248 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013 / The West Indian manatee (Trichechus manatus) and the Amazonian manatee (Trichechus inunguis) belong to the mammalian Order Sirenia, classified respectively as critically endangered and as vulnerable in Brazil. Both species have been hunted commercially since the sixteenth century, resulting in a drastic reduction or elimination of manatees in some places. This hunting pressure may have caused isolation of the populations resulting in geographic genetic isolation, with a reduction of their genetic diversity. The objective of this study is to understand the genetic diversity and population structure of the West Indian manatee (T. manatus) in Brazil; verify the existence of hybridization between the manatees T. manatus and T. inungus; define the degree of relatedness of individuals in captivity; and provide strategies for the conservation of the species. In northeastern Brazil, a large number of dependent calves strand on beaches. Many of these calves have been rescued alive and rehabilitated for future release. Previously, the identification of release sites did not take into account the genetic issues. Through this study, it has been possible to identify suitable release sites based on phylogenetic traits of the manatees. The genetic structure of the population was studied using nuclear DNA in the program STRUCTURE, and comparing FST and RST values. On the Northeast coast one population was identified, which is subdivided in two subpopulations. A different genetic population was found in the Northwest of the Amazon River estuary (extreme north of Brazil, Guyana and Venezuelan). Manatees from the Estuary of the Amazon River grouped with Amazonian manatees from the Santarém region to form a third population. A total of four manatee Management Units were identified along the Brazilian coast, which should be treated separately for management and conservation needs. Using a combination of molecular markers (mtDNA and nDNA) and cytogenetic analyses the existence of hybridization between T. manatus and T inunguis was confirmed, although this does not appear to be a frequent occurrence. Some of the dependent calves rescued, and other individuals transferred from irregular captive conditions to the CMA/ICMBio, were kept together and breeding occurred. Maintaining related manatees together can lead to inbreeding. It was possible 29 to establish the degree of relatedness between individuals kept at CMA/ICMBio and verify the extistence of inbreeding. To avoid inbreeding, hybridization, and overpopulation in captivity, it is necessary that males and females be separated immediately, thereby preventing reproduction ex-situ. The present study allows us to establish actions for the conservation of the West Indian manatee. Actions that should be prioritized include: protection and restoration of habitat with the creation and implementation of specific protected areas; creation and maintenance of travel corridors that allow gene flow; reduction and elimination of anthropogenic pressures on the species; stopping pointless reproduction in captivity; designing further studies in the north of Brazil to better understand the hybridization and implement the action plan.

Advances in high-throughput genomic technologies have facilitated the collection of DNA information for thousands of individuals, providing unprecedented opportunities to explore the genetic architecture of complex disease. One important finding has been that the majority of variants in the human genome are low in frequency or rare. It has been hypothesised that recent explosive growth of the human population afforded unexpectedly large amounts of rare variants with potentially deleterious effects, suggesting that rare variants may play a role in disease predisposition. But, importantly, rare variants embody a source of information through which we may learn more about our recent evolutionary history. In this thesis, I developed several statistical and computational methods to address problems associated with the analysis of rare variants and, foremost, to leverage the genealogical information they encode. First, one constraint in genome-wide association studies is that lower-frequency variants are not well captured by genotyping methods, but instead are predicted through imputation from a reference dataset. I developed the meta-imputation method to improve imputation accuracy by integrating genotype data from multiple, independent reference panels, which outperformed imputations from separate references in almost all comparisons (mean correlation with masked genotypes r²>0.9). I further demonstrated in simulated case-control studies that meta-imputation increased the statistical power to identify low-frequency variants of intermediate or high penetrance by 2.2-3.6%. Second, rare variants are likely to have originated recently through mutation and thereby sit on relatively long haplotype regions identical by descent (IBD). I developed a method that exploits rare variants as identifiers for shared haplotype segments around which the breakpoints of recombination are detected using non-probabilistic approaches. In coalescent simulations, I show that such breakpoints can be inferred with high accuracy (r²>0.99) around rare variants at frequencies <0.05%, using either haplotype or genotype data. Third, I show that technical error poses a major problem for the analysis of whole-genome sequencing or genotyping data, particularly for alleles below 0.05% frequency (false positive rate, FPR=0.1). I therefore propose a novel approach to infer IBD segments using a Hidden Markov Model (HMM) which operates on genotype data alone. I incorporated an empirical error model constructed from error rates I estimated in publicly available sequencing and genotyping datasets. The HMM was robust in presence of error in simulated data (r²>0.98) while nonprobabilistic methods failed (r²<0.02). Lastly, the age of an allele (the time since its creation through mutation) may provide clues about demographic processes that resulted in its observed frequency. I present a novel method to estimate (rare) allele age based on the inferred shared haplotype structure of the sample. The method operates in a Bayesian framework to infer pairwise coalescent times from which the age is estimated using a composite posterior approach. I show in simulated data that coalescent time can be inferred with high accuracy (rank correlation >0.91) which resulted in a likewise high accuracy for estimated age (>0.94). When applied to data from the 1000 Genomes Project, I show that estimated age distributions were overall conform with frequency-dependent expectations under neutrality, but where patterns of low frequency and old age may hint at signatures of selection at certain sites. Thus, this method may prove useful in the analysis of large cohorts when linked to biomedical phenotype data.

The aim of this work was to describe the spatial distribution of genetic variability of the northern white-breasted hedgehog (E. roumanicus), mainly within the Balkan Peninsula and Central Europe, as these areas are crucial for understanding the effects of Pleistocene climate oscillations on the genetic architecture of the species. Based on this spatial distribution, hypotheses about the possible structuring of the Balkan refugia were formulated. A total of 260 individuals and 9 microsatellite loci were used for the analysis. Using the approach of landscape and population genetics several possible isolated subpopulations within the area surveyed were identified. Unique status was proved for a population originating from Crete, probably influenced by mechanisms of island evolution. Differences from the rest of the range were ascertained also in population from the Czech Republic, located in a secondary contact zone with the E. europeaus. The role of interspecific interactions and possible introgression should be considered in this case. In the area of Romania and the area south of the Balkan Peninsula the highest genetic distances between individuals were identified, probably associated with the occurrence of geographical barriers and the possible presence of glacial subrefugia. Other identified...

Genome-wide association studies (GWAS) exploit the correlation in ge- netic diversity along chromosomes in order to detect effects on disease risk without having to type causal loci directly. The inevitable downside of this approach is that, when the correlation between the marker and the causal variant is imperfect, the risk associated with carrying the predisposing allele is diluted and its effect is underestimated. This thesis explores four different facets of this risk dilution: (1) estimating true effect sizes from those observed in GWAS; (2) asking how the context of a GWAS, including the population studied, the genotyping chip employed, and the use of im- putation, affects risk estimates; (3) assessing how often the best-associated SNP in a GWAS coincides with the causal variant; and (4) quantifying how departures from the simplest disease risk model at a causal variant distort the observed disease risk model. Using simulations, where we have information about the true risk at the causal locus, we show that the correlation between the marker and the causal variant is the primary driver of effect size underestimation. The extent of the underestimation depends on a number of factors, including the population in which the study is conducted, the genotyping chip employed, whether imputation is used, and the strength, frequency, and disease model of the risk allele. Suppose that a GWAS study is conducted in a European population, with an Affymetrix 6.0 genotyping chip, without imputation, and that the causal loci have a modest effect on disease risk, are common in the population, and follow an additive disease risk model. In such a study, we show that the risk estimated from the most associated SNP is very close to the truth approximately two-thirds of the time (although we predict that fine mapping of GWAS loci will infrequently identify causal variants with considerably higher risk), and that the best-associated variant is very often perfectly or nearly-perfectly correlated with, and almost always within 0.1cM of, the causal variant. However, the strong correlations among nearby loci mean that the causal and best-associated variants coincide infrequently, less than one-fifth of the time, even if the causal variant is genotyped. We explore ways in which these results change quantitatively depending on the parameters of the GWAS study. Additionally, we demonstrate that we expect to identify substantial deviations from the additive disease risk model among loci where association is detected, even though power to detect departures from the model drops off very quickly as the correlation between the marker and causal loci decreases. Finally, we discuss the implications of our results for the design and interpretation of future GWAS studies.

Introdução: A investigação de genes associados a doenças complexas em estudos caso-controle, baseada na frequência de variantes polimórficas, pode não ser adequada na presença de estratificação populacional advinda da mistura étnica, que é uma das características da população brasileira. Torna-se, portanto, difícil utilizar esta metodologia, pelo risco de associações espúrias devido às diferenças no background genético dos indivíduos casos e controles. Marcadores informativos de ancestralidade (AIMs) podem ser aplicados para estimar ancestralidade e corrigir estas distorções. As mesmas variantes genéticas de susceptibilidade para o diabetes tipo 1 autoimune (DM1A) como os alelos HLADR3- DR4 e os polimorfismos do PTPN22, CTLA4 e VNTR-INS presentes em caucasianos não foram sempre encontradas com a mesma frequência na nossa população com DM1A, ou conferiram risco menor quando presentes. Tais diferenças podem advir da nossa miscigenação. Portanto, no presente estudo, objetivou-se: 1) Analisar uma amostra de portadores de DM1A da cidade de São Paulo e controles não diabéticos, utilizando marcadores genéticos autossômicos de ancestralidade, identificando os componentes ancestrais individuais e os da população, permitindo assim, maior compreensão da sua potencial estratificação; 2) Verificar o papel dos alelos do sistema HLA-DR e DQ, dos polimorfismos dos genes PTPN22, CTLA4 e INS-VNTR, na predisposição à doença, corrigindo para o viés introduzido pela estratificação da nossa população. Materiais e métodos: 915 pacientes com DM1A, idade de 24,6±13,0 anos, 81,7% autorreferidos brancos e 789 controles, idade 28,5 ± 11,5 anos, 65,6% autorreferidos brancos participaram do estudo. A genotipagem dos 93 marcadores informativos de ancestralidade foi realizada por meio da plataforma BeadXpress (Illumina, EUA). A composição ancestral dos indivíduos foi caracterizada pelo programa Structure 2.3, e os alelos e variantes dos genes candidatos, testados por meio de análise structured association, utilizando o programa STRAT. Resultados: A ancestralidade européia prevaleceu no grupo de pacientes com DM1A e nos controles, (77% e 71%, respectivamente), seguida pela africana e ameríndia. Os alelos - DRB1*0301, -DR4 (subtipos -*0401, -*0402, -*0405) e - DR*09, e os alelos DQB1*0201 e -*0302 foram confirmados como predisponentes, mesmo após a correção para a estrutura de nossa população, assim como os alelos protetores- DRB1 (*0302, -*07, -*10, -*11, -*13, -*14 e -*15) e -DQB1 (*0402, -*0503, -*0602 e -*0603). Os haplótipos DRB1*0301/DQB1*0201, - *0401/0302, -*0402/0302, -*0405/0302, -*09/0202 predominaram no grupo DM1A, enquanto -*0302/0402, -*07/0202, -*10/0501, -*11/0301, -*11/0602, - *13/0603, -*14/0503 e -*15/0602 conferiram proteção. A correção para estratificação evidenciou o alelo DRB1*16 e o haplótipo -*07/0201 como de proteção e o DQB1*0501, que inicialmente era de proteção, como neutro. Também confirmou o haplótipo -*09/0202, como de risco e o -*0302/0402, de proteção, à semelhança do observado em afro-americanos. Os haplótipos - *10/0501, -*11/0602 e -*13/0603, protetores na nossa população e em afroamericanos, foram neutros nos caucasianos. A susceptibilidade determinada pelos genótipos I/I do INS VNTR e CT + TT do gene PTPN22 foram confirmadas após correção para estrutura populacional. O polimorfismo CTLA4 rs231775A > G não pôde ser avaliado. Conclusão: Evidenciamos diferenças nas variantes genéticas de susceptibilidade e proteção ao DM1A na nossa população em relação às caucasianas e afroamericanas, possivelmente decorrentes da mistura étnica. A correção para a estrutura populacional foi importante para confirmar a característica de proteção conferidas pelo alelo -DRB1*16 e haplótipo -*07/0201 / Introduction: The investigation of genes associated with complex diseases in case-control studies, based on the frequency of polymorphic variants, may not be appropriate in the presence of population stratification arising from the ethnic admixture, which is characteristic of the Brazilian population. It is therefore difficult to apply this method, due to the risk of spurious associations related to differences in the genetic background of individual cases and controls. Ancestry informative markers (AIMs) can be used to estimate ancestry and correct these distortions. The same genetic variants of susceptibility to type 1 autoimmune diabetes (T1AD) like HLA- DR3 -DR4 alleles and polymorphisms in PTPN22, CTLA4 and VNTR-INS genes usually present in caucasians were not always found at the same frequency in our population with T1AD, or conferred lower risk when present. These discrepancies may result from our miscigenation. Therefore, in this study, we aimed to: 1) analyze a sample of patients with T1AD and health controls, mostly living in São Paulo, using genetic autosomal markers of ancestry, to identify the ancestry of individual components and of the population, that could identify its potential stratification; 2) Evaluate the role of HLA-DR and -DQ alleles and polymorphisms of PTPN22, CTLA4 and INSVNTR genes in the predisposition to disease, correcting for the bias introduced by the stratification of our population. Methods: 915 patients with T1D, aged 24.6±13.0 years, 81.7% self-reported as white and 789 controls, aged 28.5±11.5 years, 65.6% self-reported as white participated of the study. Genotyping of 93 informative markers was performed by BeadXpress platform (Illumina, USA). The ancestry composition of individuals was characterized by Structure 2.3 program, and variants and alleles of candidate genes were tested using structured association analysis with the STRAT program. Results: The european ancestry prevailed in T1AD and control groups (77% and 71%, respectively), followed by african and amerindian. The -DRB1*0301, -DR4 (subtypes -*0401, -*0402, -*0405) and -DR*09 alleles as well as -DQB1 *0201 and -*0302 alleles were confirmed as predisposing to T1AD, even after correcting for the structure of our population. The same was observed for the protective alleles: -DRB1 (-*0302, - *07, -*10, -*11, -*13, -*14 and -*15) and - DQB1 (-*0402, -* 0503, -*0602 and -*0603). HLA-DRB1*0301/DQB1*0201, - *0401/0302, -*0402/0302, -*0405/0302, -*09/0202 haplotypes predominated in T1AD group, while -*0302/0402, -*07/0202, -*10/0501, -*11/0301, -*11/0602, - *13/0603, -*14/0503 and -*15/0602 conferred protection. The correction for stratification evidenced DRB1*16 allele and -*07/0201 haplotype as protective and DQB1*0501, initially associated with protection, as neutral. This analysis also confirmed the -*09/0202, as a risk haplotype and -*0302/0402, -*10/0501, - *11/0602 and -*13/0603 as protective in our population, similar to reported in african-americans, although neutral in caucasians.The susceptibility to T1AD determined by INS VNTR I/I and PTPN22 CT+TT haplotypes were confirmed after correcting for population structure. The CTLA4 rs231775 A > G polymorphism could not be evaluated. Conclusion: We demonstrated differences in genetic variants associated with susceptibility and protection to T1AD in our population when compared to caucasian and african-american Abstract populations, possibly due to the ethnic admixture. The correction for the population structure was important to confirm the protection conferred by - DRB1*16 allele and -*07/0201 haplotype

Introdução: A investigação de genes associados a doenças complexas em estudos caso-controle, baseada na frequência de variantes polimórficas, pode não ser adequada na presença de estratificação populacional advinda da mistura étnica, que é uma das características da população brasileira. Torna-se, portanto, difícil utilizar esta metodologia, pelo risco de associações espúrias devido às diferenças no background genético dos indivíduos casos e controles. Marcadores informativos de ancestralidade (AIMs) podem ser aplicados para estimar ancestralidade e corrigir estas distorções. As mesmas variantes genéticas de susceptibilidade para o diabetes tipo 1 autoimune (DM1A) como os alelos HLADR3- DR4 e os polimorfismos do PTPN22, CTLA4 e VNTR-INS presentes em caucasianos não foram sempre encontradas com a mesma frequência na nossa população com DM1A, ou conferiram risco menor quando presentes. Tais diferenças podem advir da nossa miscigenação. Portanto, no presente estudo, objetivou-se: 1) Analisar uma amostra de portadores de DM1A da cidade de São Paulo e controles não diabéticos, utilizando marcadores genéticos autossômicos de ancestralidade, identificando os componentes ancestrais individuais e os da população, permitindo assim, maior compreensão da sua potencial estratificação; 2) Verificar o papel dos alelos do sistema HLA-DR e DQ, dos polimorfismos dos genes PTPN22, CTLA4 e INS-VNTR, na predisposição à doença, corrigindo para o viés introduzido pela estratificação da nossa população. Materiais e métodos: 915 pacientes com DM1A, idade de 24,6±13,0 anos, 81,7% autorreferidos brancos e 789 controles, idade 28,5 ± 11,5 anos, 65,6% autorreferidos brancos participaram do estudo. A genotipagem dos 93 marcadores informativos de ancestralidade foi realizada por meio da plataforma BeadXpress (Illumina, EUA). A composição ancestral dos indivíduos foi caracterizada pelo programa Structure 2.3, e os alelos e variantes dos genes candidatos, testados por meio de análise structured association, utilizando o programa STRAT. Resultados: A ancestralidade européia prevaleceu no grupo de pacientes com DM1A e nos controles, (77% e 71%, respectivamente), seguida pela africana e ameríndia. Os alelos - DRB1*0301, -DR4 (subtipos -*0401, -*0402, -*0405) e - DR*09, e os alelos DQB1*0201 e -*0302 foram confirmados como predisponentes, mesmo após a correção para a estrutura de nossa população, assim como os alelos protetores- DRB1 (*0302, -*07, -*10, -*11, -*13, -*14 e -*15) e -DQB1 (*0402, -*0503, -*0602 e -*0603). Os haplótipos DRB1*0301/DQB1*0201, - *0401/0302, -*0402/0302, -*0405/0302, -*09/0202 predominaram no grupo DM1A, enquanto -*0302/0402, -*07/0202, -*10/0501, -*11/0301, -*11/0602, - *13/0603, -*14/0503 e -*15/0602 conferiram proteção. A correção para estratificação evidenciou o alelo DRB1*16 e o haplótipo -*07/0201 como de proteção e o DQB1*0501, que inicialmente era de proteção, como neutro. Também confirmou o haplótipo -*09/0202, como de risco e o -*0302/0402, de proteção, à semelhança do observado em afro-americanos. Os haplótipos - *10/0501, -*11/0602 e -*13/0603, protetores na nossa população e em afroamericanos, foram neutros nos caucasianos. A susceptibilidade determinada pelos genótipos I/I do INS VNTR e CT + TT do gene PTPN22 foram confirmadas após correção para estrutura populacional. O polimorfismo CTLA4 rs231775A > G não pôde ser avaliado. Conclusão: Evidenciamos diferenças nas variantes genéticas de susceptibilidade e proteção ao DM1A na nossa população em relação às caucasianas e afroamericanas, possivelmente decorrentes da mistura étnica. A correção para a estrutura populacional foi importante para confirmar a característica de proteção conferidas pelo alelo -DRB1*16 e haplótipo -*07/0201 / Introduction: The investigation of genes associated with complex diseases in case-control studies, based on the frequency of polymorphic variants, may not be appropriate in the presence of population stratification arising from the ethnic admixture, which is characteristic of the Brazilian population. It is therefore difficult to apply this method, due to the risk of spurious associations related to differences in the genetic background of individual cases and controls. Ancestry informative markers (AIMs) can be used to estimate ancestry and correct these distortions. The same genetic variants of susceptibility to type 1 autoimmune diabetes (T1AD) like HLA- DR3 -DR4 alleles and polymorphisms in PTPN22, CTLA4 and VNTR-INS genes usually present in caucasians were not always found at the same frequency in our population with T1AD, or conferred lower risk when present. These discrepancies may result from our miscigenation. Therefore, in this study, we aimed to: 1) analyze a sample of patients with T1AD and health controls, mostly living in São Paulo, using genetic autosomal markers of ancestry, to identify the ancestry of individual components and of the population, that could identify its potential stratification; 2) Evaluate the role of HLA-DR and -DQ alleles and polymorphisms of PTPN22, CTLA4 and INSVNTR genes in the predisposition to disease, correcting for the bias introduced by the stratification of our population. Methods: 915 patients with T1D, aged 24.6±13.0 years, 81.7% self-reported as white and 789 controls, aged 28.5±11.5 years, 65.6% self-reported as white participated of the study. Genotyping of 93 informative markers was performed by BeadXpress platform (Illumina, USA). The ancestry composition of individuals was characterized by Structure 2.3 program, and variants and alleles of candidate genes were tested using structured association analysis with the STRAT program. Results: The european ancestry prevailed in T1AD and control groups (77% and 71%, respectively), followed by african and amerindian. The -DRB1*0301, -DR4 (subtypes -*0401, -*0402, -*0405) and -DR*09 alleles as well as -DQB1 *0201 and -*0302 alleles were confirmed as predisposing to T1AD, even after correcting for the structure of our population. The same was observed for the protective alleles: -DRB1 (-*0302, - *07, -*10, -*11, -*13, -*14 and -*15) and - DQB1 (-*0402, -* 0503, -*0602 and -*0603). HLA-DRB1*0301/DQB1*0201, - *0401/0302, -*0402/0302, -*0405/0302, -*09/0202 haplotypes predominated in T1AD group, while -*0302/0402, -*07/0202, -*10/0501, -*11/0301, -*11/0602, - *13/0603, -*14/0503 and -*15/0602 conferred protection. The correction for stratification evidenced DRB1*16 allele and -*07/0201 haplotype as protective and DQB1*0501, initially associated with protection, as neutral. This analysis also confirmed the -*09/0202, as a risk haplotype and -*0302/0402, -*10/0501, - *11/0602 and -*13/0603 as protective in our population, similar to reported in african-americans, although neutral in caucasians.The susceptibility to T1AD determined by INS VNTR I/I and PTPN22 CT+TT haplotypes were confirmed after correcting for population structure. The CTLA4 rs231775 A > G polymorphism could not be evaluated. Conclusion: We demonstrated differences in genetic variants associated with susceptibility and protection to T1AD in our population when compared to caucasian and african-american Abstract populations, possibly due to the ethnic admixture. The correction for the population structure was important to confirm the protection conferred by - DRB1*16 allele and -*07/0201 haplotype

As sequencing technology continues to produce better quality genomes at decreasing costs, there has been a recent surge in the variety of data that we are now able to analyze. This is particularly true with regards to our understanding of the human genome—where the last decade has seen data advances in primate epigenomics, ancient hominid genomics, and a proliferation of human polymorphism data from multiple populations. In order to utilize such data however, it has become critical to develop increasingly sophisticated tools spanning both bioinformatics and statistical inference. In population genetics particularly, new statistical approaches for analyzing population data are constantly being developed—unfortunately, often without proper model testing and evaluation of type-I and type-II error. Because the common Wright-Fisher assumptions underlying such models are generally violated in natural populations, this statistical testing is critical. Thus, my dissertation has two distinct but related themes: 1) evaluating methods of statistical inference in population genetics, and 2) utilizing these methods to analyze the evolutionary history of humans and our closest relatives. The resulting collection of work has not only provided important biological insights (including some of the first strong evidence of selection on human-specific epigenetic modifications (Shulha, Crisci, Reshetov, Tushir et al. 2012, PLoS Bio), and a characterization of human-specific genetic changes distinguishing modern humans from Neanderthals (Crisci et al. 2011, GBE)), but also important insights in to the performance of population genetic methodologies which will motivate the future development of improved approaches for statistical inference (Crisci et al, in review).

Monitoring the distribution, abundance and demography of species is vital to ensure that conservation efforts are appropriate and effective. Monitoring enables evaluation of responses to natural or human disturbance, highlights the need for management interventions and enables these interventions to be assessed and refined. The methods used largely depend on the specific aim of monitoring and behaviour of the target species, as well as the time and spatial scale that monitoring is required to cover. The European pine marten (Martes martes) is one of few remaining mammalian predators native to the UK. Since persecution in the early 19th century resulted in their near extinction, pine martens have recovered part of their former range in Scotland. Their recent recovery and an overlap in territory with vulnerable prey species such as the capercaillie (Tetrao urogallus) make the collection of accurate baseline data and subsequent monitoring of population trends vital for conservation efforts. Faecal counts have traditionally been used to provide a relative measure of population density for pine marten. In most cases, absolute measures of population density require individual identification. Non-invasive genotyping can provide this information but the quality of DNA from these samples is often poor. Here, the process is refined for pine marten faeces (scats) and hair samples. DNA degradation increased significantly for scats exposed to rainfall, with the rate of DNA amplification success reduced by 38% over a 16 day period. Success rates for hair samples were higher when more hair follicles were included in the analysis. Population densities were estimated for three forests in Scotland using a robust combination of non-invasive genotyping of hair samples and spatially explicit capture recapture modelling. Population density estimates of 0.07 (95% CI 0.03 - 0.16) to 0.38 km-2 (95% CI 0.11 - 1.07) were obtained which are within the range of previous estimates for forests elsewhere in Scotland. The first attempt to quantify the relationship between traditional scat counts and home range size was then conducted; a significant negative correlation exists but only when population density is relatively low. Previous studies suggest that pine martens in Western Europe are less forest dependent than those in Eastern Europe. Results from this thesis support this, with populations at the highest density found at sites with intermediate forest cover. This tolerance of lower forest cover is also apparent in the diet. Despite a preference for Myodes voles in populations in Eastern Europe, those in Western Europe show a strong preference for Microtus voles as well as a higher level of frugivory. We assess the autumn diet of four populations in Scotland assess the effect of forest cover and sex on the diet. There was no evidence of differential consumption of Microtus voles or birds between the sexes. Our analysis shows that frugivory is influenced by forest fragmentation, with a 5-fold increase in the occurrence of fruit (from 2% to 10%) as forest cover increased from 4% to 47%. Diversionary feeding has been suggested as a management technique to reduce the depredation of capercaillie by pine martens. This thesis presents the first attempt to quantify the success and cost-efficacy of diversionary feeding for a range of problems (crop damage, threatened safety, livestock depredation) across 30 experimental trials. The strategy proved more effective when targeted towards food-limited populations, and when aiming to alleviate habitat damage or risks to human safety rather than depredation. A novel decision-making framework was developed to aid managers with the initial planning of the strategy and its subsequent implementation within an adaptive format. Further to this, the feasibility of using diversionary feeding with a view to reduce the depredation of capercaillie by pine martens was assessed. Questionnaire responses were collected from people who have provided food for pine martens throughout Scotland. A positive reaction to food was observed, with 58% of respondents reporting that initial visits occurred within one week of placement and 46% reporting that subsequent visits were received daily. These results suggest that diversionary feeding may be a viable option for pine marten management, although testing of its impact on capercaillie productivity would be required.