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We consider stochastic growth models to represent population dynamics subject to geometric catastrophes. We analyze different dispersion schemes after catastrophes, to study how these schemes impact the population viability and comparing them with the scheme where there is no dispersion. In the schemes with dispersion, we consider that each colony, after the catastrophe event, has $d$ new positions to place its survivors. We find out that when $d = 2$ no type of dispersion considered improves the chance of survival, at best it matches the scheme where there is no dispersion. When $d = 3$, based on the survival probability, we conclude that dispersion may be an advantage or not, depending on its type, the rate of colony growth and the probability that an individual will survive when exposed to a catastrophe., 17 pages, 4 figures

ABSCTRACT: Eugenia involucrata DC. is a forest species with high environmental and economic potential. The objective of this study was to quantify the genetic variability and analyzed the genetic structure of three natural fragments located in the central region of the Rio Grande do Sul state, Brazil. We used four microsatellite loci developed for the congener species Eugenia uniflora and using GenAlEx 6.5 software, parameters of genetic variability and its partition among and within fragments were estimated for each locus. We observed high levels of genetic variability (3.67 alleles per locus; HO = 0.815; HE = 0.625; FIS = −0.294), most of which (93%) were distributed within the fragments, suggesting that these individuals came from a single original population. Gene flow between fragments was high (2.35 to 4.56 migrants per generation), resulting in low genetic differentiation indexes (FST values ranging from 0.052 to 0.096). The fragments showed high genetic variability, distributed within the remnants themselves, and low genetic differentiation. Our results have repercussions for planning locally adapted germplasm collections for forest restoration programs, thereby avoiding the implantation of populations with an exogamous depression. RESUMO: Eugenia involucrata DC. é uma espécie florestal com elevado potencial ambiental e econômico. O presente trabalho teve por objetivo quantificar a variabilidade e analisar a estruturação genética em três fragmentos naturais localizados na região central do estado do Rio Grande do Sul, Brasil. Com o emprego de quatro locos microssatélites desenvolvidos para a espécie congênere Eugenia uniflora e usando-se o software GenAlEx 6.5, foram estimados parâmetros de variabilidade genética, para cada loco, e sua partição entre e dentro dos fragmentos. Foram observados altos índices de variabilidade genética (3,67 alelos por loco; HO = 0,815; HE = 0,625; FIS = -0,294), com a maior proporção (93%) distribuída dentro dos fragmentos, sugerindo que os indivíduos estudados são provenientes de uma única população original. O fluxo gênico foi elevado entre os fragmentos, variando de 2,35 a 4,56 migrantes por geração, resultando em baixo índice de diferenciação genética (FST), entre 0,052 a 0,096. Os fragmentos estudados apresentam elevada variabilidade genética, a maior parte distribuída dentro dos próprios remanescentes, e baixa diferenciação genética. Os resultados observados têm repercussões no planejamento de coleta de germoplasma com adaptação local para programas de restauração florestal, assim evitando a implantação de populações com depressão exogâmica.

Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species' range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the dewlap colors of Amazon Slender Anoles, Anolis fuscoauratus. To this aim, we characterized dewlap diversity in the field with respect to population genetic structure and evolutionary relationships, assessed whether dewlap phenotypes are associated with climate or landscape variables, and tested for nonrandom associations in the distributions of A. fuscoauratus phenotypes and sympatric Anolis species. We found that dewlap colors vary among but not within sites in A. fuscoauratus. Regional genetic clusters included multiple phenotypes, while populations with similar dewlaps were often distantly related. Phenotypes did not segregate in environmental space, providing no support for optimized signal transmission at a local scale. Instead, we found a negative association between certain phenotypes and sympatric Anolis species with similar dewlap color attributes, suggesting that interactions with closely related species promoted dewlap divergence among A. fuscoauratus populations. Amazon Slender Anoles emerge as a promising system to address questions about parallel trait evolution and the contribution of signaling traits to speciation.

Besides reviewing the unusual case of sex-ratio in the lemming and presenting alternative analyses of general models in which the shift in the usual sex-ratio 1:1 is determined by autosomal or sex-linked mutant alleles, three novel models are presented, in which the shift on the progeny sex-ratio depends on the number of copies of a mutant allele present in the parental pair. The analysis of these models with additive effects shows that: 1) autosomal mutations that alter the usual sex-ratio are eliminated from the population; 2) mutations occurring on the X chromosome lead to an evolutionary stable 1:1 sex-ratio only if the mutation favors the production of males; when the mutant allele favors the production of females, however, females will prevail in the population, with a frequency dependent impact on δ (the deviation from the usual 0.5 proportion) ; for most of the range of possible values of δ the stable but extraordinary sex-ratio will vary from 1 male : 1 female to 1 male : 3 females or 1 male : 2 females approximately depending whether the mutant allele is randomly inactivated or not.

Introducción: este artículo analiza dos estrategias de investigación puestas en acción en tres proyectos de estudio de la genética humana en México, entre 1960 y 2009. Se distingue entre una estrategia que incorpora recursos multidisciplinarios en el diseño del muestreo, el análisis e interpretación de datos (a la que se le denomina de exhibición), y una que privilegia consideraciones pragmáticas sobre los análisis multidisciplinarios (a la que se le denomina de aplanamiento). Desarrollo: se analizó el trabajo del médico hematólogo Rubén Lisker en la década de 1960, el mapeo de la diversidad genómica mexicana realizado por investigadores del Instituto Nacional de Medicina Genómica entre 2004 y 2009, y el análisis de la variación nativa llevado a cabo por el genetista Andrés Moreno (en la Universidad de Stanford en ese entonces), y sus colegas en años recientes. Conclusiones: las decisiones estratégicas que toman los científicos tienen consecuencias en la medición y caracterización de la variación genética en las poblaciones humanas, pero también sobre las prácticas sociales demográ cas y biomédicas relacionadas con su estudio. Mientras la primera estrategia exhibe de forma detallada la variación genética oculta en las poblaciones humanas, favoreciendo así la precisión y el realismo, la segunda tiende a aplanar las diferencias individuales y a perder profundidad histórica, pero privilegiando la generalización y la descripción de los grandes rasgos de una población. Introduction: This article analyzes two research strategies carried out by three projects of human genetics in Mexico, between 1960 and 2009. We distinguish between a strategy that incorporates multidisciplinary resources in the design of sampling, analysis and interpretation of data (which we call exhibition), and one that privileges pragmatic considerations on multidisciplinary analysis (which we call flattening). Development: We analyzed the work of the hematologist Rubén Lisker in the 1960s, the mapping of Mexican genomic diversity carried out by researchers from the National Institute of Genomic Medicine between 2004 and 2009, and the analysis of the native variation carried out by geneticist Andrés Moreno (then at Stanford University), and his colleagues in recent years. Conclusions: The strategic decisions taken by scientists have consequences in the measurement and characterization of genetic variation in human populations, but also in the demographic and biomedical social practices related to their study. While the first strategy exhibits detailed genetic variation hidden in human populations, thus favoring precision and realism, the second tends to flatten individual differences and lose historical depth but privileging the generalization and description of the broad features of a population. Introdução: este artigo analisa duas estratégias de pesquisa colocada em prática em três projetos de estudo da genética humana no México, entre 1960 e 2009. Distinguimos entre uma estratégia que incorpora recursos multidisciplinares no desenho da amostragem, a análise e interpretação de dados (à qual chamamos de exibição), e uma que privilegia considerações pragmáticas sobre as análises multidisciplinares (a qual chamamos de aplanamento). Desenvolvimento: analisamos o trabalho do médico hematólogo Rubén Lisker na década de 1960, o mapeamento da diversidade genômica mexicana realizado por pesquisadores do Instituto Nacional de Medicina Genômica (Inmegen) entre 2004 e 2009, e a análise da variação nativa levado a cabo pelo geneticista Andrés Moreno (para então na Universidade de Stanford), e seus colegas em anos recentes. Conclusões: as decisões estratégicas que tomam os científicos têm consequências na medição e caracterização da variação genética nas populações humanas, mas também sobre as práticas sociais demográ cas e biomédicas relacionadas com o seu estudo. Enquanto a primeira estratégia exibe de forma detalhada a variação genética oculta nas populações humanas, favorecendo assim a precisão e o realismo, a segunda tende a aplanar as diferenças individuais e a perder profundidade histórica, mas privilegiando a generalização e a descrição dos grandes rasgos de uma população.

AIM: To assess the effects of historical events on the tempo and mode of diversification of the lizard Polychrus acutirostris along the South American diagonal of open formations (DOF). LOCATION: Caatinga and Cerrado biomes in Brazil. METHODS: We sequenced fragments of one mtDNA and three nuDNA genes of 68 individuals from 33 localities. We used population assignment methods to access genetic structure and estimate lineage boundaries. Next, we estimated lineage relationships, intraspecific diversity, environmental niche similarity and demographic history. Finally, we tested 12 diversification scenarios using an approximate Bayesian computation (ABC) approach. RESULTS: We recovered three non‐overlapping, geographically structured lineages corresponding to Caatinga, north‐east Cerrado and south‐west Cerrado, with the major divergence event dating to the Late Neogene. We also recovered a complex scenario of divergence associated with gene flow and niche divergence. MAIN CONCLUSIONS: We show a complex history of diversification along the South American DOF. Our findings support the role of environmental features as the likely drivers of P. acutirostris intraspecific diversification during the Late Neogene.

Brycon nattereri is an endangered Neotropical fish reported along conserved stretches of the upper Paraná, Tocantins and São Francisco rivers. Populations of this species have been very rare in some Paraná River sub basins. This study analyzes the genetic diversity and population structure of B. nattereri in a restricted area of occurrence recently identified in upper Paraná River basin. Seven microsatellite loci and 497 bp of D-Loop mitochondrial region were examined in 92 individuals from four points along the area of occurrence. Both molecular markers indicated a single population distributed along a stretch of the river approximately 80 km long. Although some of the data suggest an ancient bottleneck, current levels of genetic diversity (H E = 0.574 and h = 0.616) were similar to those of other species of the genus Brycon. The results suggest that the population of B. nattereri has been able to maintain satisfactory levels of genetic diversity, in spite of the small area of occurrence. These data have highlighted an important conservation area and action may prove essential to improve the quality of the environment, and especially the water and riparian plant life, if the area is to be managed and conserved efficiently.

The coffee leaf miner, Leucoptera coffeella (Guerin-Meneville & Perrottet, 1842), probably infested coffee plants in Neotropical America during the 19th century. The species subsequently became a key pest of coffee plants in Brazil, but not in Colombia, the two main coffee producers in the region. The contrasting importance of the coffee leaf miner in Brazil and Colombia may be the result of the evolutionary and demographic history of this species. Therefore, our goal was to test two alternative hypotheses regarding the possible genetic origins of this species: 1) leaf miners in both countries share the same origin and 2) the leaf miner arrived in both countries independently from distinct sources and subsequently diversified without genetic exchange between countries. Thus, DNA sequence data of 21 populations were collected (Brazil, 16; Colombia, 5), and partial sequences of their cytochrome oxidase subunit I (COI), cytochrome b (Cytb), and the nuclear internal transcribed spacer (ITS) region were obtained to test these hypotheses. Both nuclear and mitochondrial molecular markers showed low nucleotide diversity. Analyses of molecular variance indicated higher variability within population in both concatenated mitochondrial genes and ITS region (70.57 and 84.01%, respectively). Finally, geno/haplotype networks showed each central geno/haplotypes that displayed high frequency and were distributed widely in both countries. Low-frequency geno/haplotypes were at tip positions connected to the central geno/haplotypes through single mutation steps, suggesting that the Neotropical coffee leaf miner in both Brazil and Colombia consists of a single species and exhibits a common and recent genetic origin.

Studies of genetic diversity and structure are key elements in designing effective in situ and ex situ management plans, especially for species experiencing forest fragmentation. To investigate the level of genetic diversity in populations of Trichocentrum pumilum, eight polymorphic microsatellite loci were developed and used for genotyping 96 specimens from four disturbed populations. Low genetic diversity within populations was found (average number of alleles per locus ranging from 3.75 to 4.25, observed and expected heterozygosities from 0.238 to 0.333 and from 0.450 to 0.482, respectively). The fixation index () ranged from 0.35 to 0.47, with significant values for all populations. No genotypic disequilibrium was detected. A mixed breeding system was found through an apparent outcrossing rate estimate. Our results suggest that these microsatellite loci are suitable for genetic studies of this species, showing low within population genetic diversity and moderate structure for T. pumilum populations.

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least ∼9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by ∼4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions. A large-scale analysis of ancient genomes from Central and South America yields insights into the peopling of the Americas, including four southward population spreads and notable population continuity in much of South America after arrival.

Environmental gradients constrain physiological performance and thus species’ ranges, suggesting that species occurrence in diverse environments may be associated with local adaptation. Genome–environment association analyses (GEAA) have become central for studies of local adaptation, yet they are sensitive to the spatial orientation of historical range expansions relative to landscape gradients. To test whether potentially adaptive genotypes occur in varied climates in wide‐ranged species, we implemented GEAA on the basis of genomewide data from the anole lizards Anolis ortonii and Anolis punctatus, which expanded from Amazonia, presently dominated by warm and wet settings, into the cooler and less rainy Atlantic Forest. To examine whether local adaptation has been constrained by population structure and history, we estimated effective population sizes, divergence times, and gene flow under a coalescent framework. In both species, divergence between Amazonian and Atlantic Forest populations dates back to the mid‐Pleistocene, with subsequent gene flow. We recovered eleven candidate genes involved with metabolism, immunity, development, and cell signaling in A. punctatus and found no loci whose frequency is associated with environmental gradients in A. ortonii. Distinct signatures of adaptation between these species are not associated with historical constraints or distinct climatic space occupancies. Similar patterns of spatial structure between selected and neutral SNPs along the climatic gradient, as supported by patterns of genetic clustering in A. punctatus, may have led to conservative GEAA performance. This study illustrates how tests of local adaptation can benefit from knowledge about species histories to support hypothesis formulation, sampling design, and landscape gradient characterization.

Supertypes are groups of human leukocyte antigen (HLA) alleles which bind overlapping sets of peptides due to sharing specific residues at the anchor positions—the B and F pockets—of the peptide-binding region (PBR). HLA alleles within the same supertype are expected to be functionally similar, while those from different supertypes are expected to be functionally distinct, presenting different sets of peptides. In this study, we applied the supertype classification to the HLA-A and HLA-B data of 55 worldwide populations in order to investigate the effect of natural selection on supertype rather than allelic variation at these loci. We compared the nucleotide diversity of the B and F pockets with that of the other PBR regions through a resampling procedure and compared the patterns of within-population heterozygosity (He) and between-population differentiation (GST) observed when using the supertype definition to those estimated when using randomized groups of alleles. At HLA-A, low levels of variation are observed at B and F pockets and randomized He and GST do not differ from the observed data. By contrast, HLA-B concentrates most of the differences between supertypes, the B pocket showing a particularly high level of variation. Moreover, at HLA-B, the reassignment of alleles into random groups does not reproduce the patterns of population differentiation observed with supertypes. We thus conclude that differently from HLA-A, for which supertype and allelic variation show similar patterns of nucleotide diversity within and between populations, HLA-B has likely evolved through specific adaptations of its B pocket to local pathogens. Electronic supplementary material The online version of this article (doi:10.1007/s00251-015-0875-9) contains supplementary material, which is available to authorized users.

A valuable approach to understand how individual and population genetic differences can predispose to disease is to assess the impact of genetic variants on cellular functions (e.g., gene expression) of cell and tissue types related to pathological states. To understand the genetic basis of nonsyndromic cleft lip with or without cleft palate (NSCL/P) susceptibility, a complex and highly prevalent congenital malformation, we searched for genetic variants with a regulatory role in a disease-related tissue, the lip muscle (orbicularis oris muscle [OOM]), of affected individuals. From 46 OOM samples, which are frequently discarded during routine corrective surgeries on patients with orofacial clefts, we derived mesenchymal stem cells and correlated the individual genetic variants with gene expression from these cultured cells. Through this strategy, we detected significant cis-eQTLs (i.e., DNA variants affecting gene expression) and selected a few candidates to conduct an association study in a large Brazilian cohort (624 patients and 668 controls). This resulted in the discovery of a novel susceptibility locus for NSCL/P, rs1063588, the best eQTL for the MRPL53 gene, where evidence for association was mostly driven by the Native American ancestry component of our Brazilian sample. MRPL53 (2p13.1) encodes a 39S protein subunit of mitochondrial ribosomes and interacts with MYC, a transcription factor required for normal facial morphogenesis. Our study illustrates not only the importance of sampling admixed populations but also the relevance of measuring the functional effects of genetic variants over gene expression to dissect the complexity of disease phenotypes.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disorder characterized by progressive cerebellar ataxia and epilepsy. The disease is caused by a pentanucleotide ATTCT expansion in intron 9 of the ATXN10 gene on chromosome 22q13.3. SCA10 has shown a geographical distribution throughout America with a likely degree of Amerindian ancestry from different countries so far. Currently available data suggest that SCA10 mutation might have spread out early during the peopling of the Americas. However, the ancestral origin of SCA10 mutation remains under speculation. Samples of SCA10 patients from two Latin American countries were analysed, being 16 families from Brazil (29 patients) and 21 families from Peru (27 patients) as well as 49 healthy individuals from Indigenous Quechua population and 51 healthy Brazilian individuals. Four polymorphic markers spanning a region of 5.2 cM harbouring the ATTCT expansion were used to define the haplotypes, which were genotyped by different approaches. Our data have shown that 19-CGGC-14 shared haplotype was found in 47% of Brazilian and in 63% of Peruvian families. Frequencies from both groups are not statistically different from Quechua controls (57%), but they are statistically different from Brazilian controls (12%) (p

The theory of morphological integration and modularity predicts that if functional correlations among traits are relevant to mean population fitness, the genetic basis of development will be molded by stabilizing selection to match functional patterns. Yet, how much functional interactions actually shape the fitness landscape is still an open question. We used the anuran skull as a model of a complex phenotype for which we can separate developmental and functional modularity. We hypothesized that functional modularity associated to functional demands of the adult skull would overcome developmental modularity associated to bone origin at the larval phase because metamorphosis would erase the developmental signal. We tested this hypothesis in toad species of the Rhinella granulosa complex using species phenotypic correlation pattern (P‐matrices). Given that the toad species are distributed in very distinct habitats and the skull has important functions related to climatic conditions, we also hypothesized that differences in skull trait covariance pattern are associated to differences in climatic variables among species. Functional and hormonal‐regulated modules are more conspicuous than developmental modules only when size variation is retained on species P‐matrices. Without size variation, there is a clear modularity signal of developmental units, but most species have the functional model as the best supported by empirical data without allometric size variation. Closely related toad species have more similar climatic niches and P‐matrices than distantly related species, suggesting phylogenetic niche conservatism. We infer that the modularity signal due to embryonic origin of bones, which happens early in ontogeny, is blurred by the process of growth that occurs later in ontogeny. We suggest that the species differing in the preferred modularity model have different demands on the orbital functional unit and that species contrasting in climate are subjected to divergent patterns of natural selection associated to neurocranial allometry and T3 hormone regulation.

The effects of global glaciations on the distribution of organisms is an essential element of many diversification models. However, the empirical evidence supporting this idea is mixed, in particular with respect to explaining tropical forest evolution. In the present study, we evaluated the impacts of range shifts associated with Pleistocene global glacial cycles on the evolution of tropical forests. In particular, we tested the predictions: (1) that population genetic structure increases with fragmentation variation between the present and the Last Glacial Maximum (LGM) and also (2) with geographical range instability; and (3) that genetic diversity increases with range stability and (4) decreases with fragmentation variation between periods. To address our predictions, we studied population genetic structures and modelled present and past distributions of 15 Atlantic Forest (AF) endemic birds. Afterwards, we evaluated the relationship of population genetic parameters with metrics of species range shifts between the present and the LGM. We found that geographical ranges of AF birds changed in concert with Pleistocene glacial cycles but, unexpectedly, our findings suggest the novel idea that ranges during glacial maxima were slightly larger on average, as well as equally fragmented and displaced from the interglacial ranges. Our findings suggest that range shifts over the late Pleistocene impacted on the diversification of forest organisms, although they did not show that those range shifts had a strong effect. We found that a combination of fragmentation variation across time, small current range size, and range stability increased population genetic structure. However, neither fragmentation, nor range stability affected genetic diversity. Our study showed that evolutionary responses to range shifts across AF birds have a high variance, which could explain the mixed support given by single-species studies to the action of Pleistocene range shifts on population evolution. Fil: Cabanne, Gustavo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Calderón, Pablo Luciano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Trujillo Arias, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Flores, Pamela. Universidad Nacional de General Sarmiento; Argentina Fil: Pessoa, Rodrigo. Universidade Estadual de Montes Claros; Brasil Fil: d'Horta, Fernando M.. Instituto Nacional de Pesquisas da Amazônia; Brasil Fil: Miyaki, Cristina Y.. Universidade de Sao Paulo; Brasil

The geographical distribution of Amblyomma parvum Aragao 1908 in the New World is disjunct, with two main clusters separated from each other by the Amazon basin. The main objectives of this study were to further investigate the systematic relationships within A. parvum, to determine whether or not populations from different geographical areas might represent cryptic species, and to reconstruct the phylogeographical evolutionary history of the species. The genetic diversity of A. parvum collected throughout its distributional range was analyzed by using 6 molecular markers: 5 mitochondrial [the small and the large ribosomal subunits 12rDNA and 16SrDNA, the cytochrome oxidase I (COI) and II (COII) and the control region or d-loop (DL)], and one nuclear (ITS2, Inter transcribed spacer 2). Phylogenetic trees were inferred by using maximum parsimony and Bayesian analyses. In addition, node dating was attempted for the main lineages identified phylogenetically. Although mitochondrial and nuclear topologies were not totally congruent, they all identified at least two main supported clusters, a Central American lineage, and a Brazilian-Argentinian lineage. Clade support and divergence values strongly suggest that the two lineages correspond to different taxonomic entities. Node dating placed the split between the Central American and the Brazilian-Argentinian lineages at approximately 5.8-4.9 Mya, just after the progressive replacement of the dry areas that occupied the northern part of South America by the Amazon Basin in the early-mid Miocene. This event might be the cause of fragmentation and putative speciation within the ancestral relatively xerophilic A. parvum population.

In Uruguay, reforestations with Eucalyptus sp. is of fundamental importance to supply paper, pulp, and wood production. This study investigates genetic, productivity, stability, and adaptability parameters in the selection of Eucalypts grandis x Eucalyptus globulus full-sib hybrid clones. The study was conducted in a clonal test, repeated in two different soils types, in Rio Negro State, Uruguay. The population was characterized phenotypically for diameter at breast height (dbh) and genotyped for SNP markers (EuCHIP60K chip). Mean dbh was similar between sites and the genotype?environment interaction was simple. We found high genotype correlation in clone performance between environments (0.708), indicating the possibility of selecting the same clones for both study locations. Mean heritability between clones (0.724), coefficient of individual genetic variation (10.9 %), and relative variation (0.916), suggest the possibility of gains (estimated at 3.1 % for both sites together) by selecting clones with higher growth rates. A total of 15,196 SNPs were used to confirm parentage and test a genomic selection model for dbh. The predictive capacity was negative (-0.15) given the small population size (78 individuals). The most adaptable material among the tested study sites presented higher values for SNP heterozygosity. Thus, using molecular markers to identify clones responsive to environmental changes can act as a powerful tool in Eucalyptus breeding programs. The hybrid population showed greater adaptability than E. globulus for this region. Made available in DSpace on 2017-11-29T23:19:43Z (GMT). No. of bitstreams: 1 2016AnandaSGClonal.pdf: 2306761 bytes, checksum: 16c9ed6eec999b80eaffd677b4f1ce0e (MD5) Previous issue date: 2017-11-29

Made available in DSpace on 2016-07-07T12:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2012. Added 1 bitstream(s) on 2016-07-07T12:44:40Z : No. of bitstreams: 1 ISSN1809-3647-2012-32-71-269-276.pdf: 466157 bytes, checksum: 194656bda7a037e4b4a36130646b88d2 (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) O presente estudo objetivou estimar parâmetros genéticos e a variabilidade entre o dentro de procedências, para caracteres silviculturais em um teste de procedências e progênies de Handroanthus vellosoi (Toledo) Mattos estabelecido na Estação Experimental de Luiz Antônio (SP). O teste foi instalado no delineamento experimental de blocos de famílias compactas, com duas procedências (alocadas nas parcelas), seis repetições e sub-parcelas lineares de cinco plantas, totalizando 35 progênies. O ensaio foi mensurado para os caracteres diâmetro à altura do peito, altura da planta, volume cilíndrico, forma do fuste e sobrevivência aos 24 anos de idade. Diferenças significativas entre procedências foram observadas apenas para o caráter forma do fuste. Pela análise de deviance foram detectadas diferenças significativas para o efeito de progênies para análise conjunta das procedências (população experimental), sugerindo que esta tem alta variação genética e indicando possibilidade de melhoramento genético pela seleção das melhores progênies. A estimativa de herdabilidade em nível individual e média de progênies variaram de baixa a moderada (26% para DAP, 32% para altura, 24% para volume cilíndrico, 27% para forma do fuste e 46% para sobrevivência), confirmando a possibilidade de melhoramento genético por seleção e que as procedências tem potencial para responder à pressão de seleção natural. The present study aimed at estimating genetic parameters and variability among and within provenances for silvicultural traits of Handroanthus vellosoi (Toledo) Mattos, in provenances and progenies test stands, located at the Luiz Antônio Experimental Station (São Paulo State, Brazil). The test was established in the compact family block design, with two provenances (allocated in the plots), siz replicates and sub-linear plots of five plants, totalizing 35 progenies. Diameter at breast (DBH), plant height, cylindrical volume, stem form and survival at 24 years of age were evaluated. Significant differences among the provenances were observed only to the trait stem form. The analysis of deviance showed significant differences among progenies for the joint analysis of the provenances (experimental population), suggesting that the population has high genetic variation and indicating the possibility of genetic improvement by selection of the best progrnies. Heritability estimates in individual and family level ranged from low to moderate (26% for DBH, 32% for plant height, 24% for cylindrical volume, 27% for form and 36% for survival), confirming the possibility of genetic improvement by selection and that the provenances have potential to respond to the pressure of natural selection. Universidade Estadual Paulista (UNESP), Faculdade de Engenharia de Ilha Solteira, Av. Brasil Centro, 56, CEP 15385-000, Ilha Solteira, SP, Brasil Instituto Florestal, Rua do Horto, 931, CEP 02377-000, São Paulo, SP, Brasil. Universidade Estadual Paulista (UNESP), Faculdade de Engenharia de Ilha Solteira, Av. Brasil Centro, 56, CEP 15385-000, Ilha Solteira, SP, Brasil CNPq: 402026/2008-0

Genetic variability of a population of Aedes aegypti from Paraná, Brazil, using the mitochondrial ND4 gene. To analyze the genetic variability of populations of Aedes aegypti, 156 samples were collected from 10 municipalities in the state of Paraná, Brazil. A 311 base pairs (bp) region of the NADH dehydrogenase subunit 4 (ND4) mitochondrial gene was examined. An analysis of this fragment identified eight distinct haplotypes. The mean genetic diversity was high (h = 0.702; p = 0.01556). AMOVA analysis indicated that most of the variation (67%) occurred within populations and the F ST value (0.32996) was highly significant. F ST values were significant in most comparisons among cities. The isolation by distance was not significant (r = -0.1216 and p = 0, 7550), indicating that genetic distance is not related to geographic distance. Neighbor-joining analysis showed two genetically distinct groups within Paraná. The DNA polymorphism and AMOVA data indicate a decreased gene flow in populations from Paraná, which can result in increased vectorial competence. Variabilidade genética de uma população de Aedes aegypti do Paraná, Brasil, usando o gene mitocondrial ND4. Para analisar a variabilidade genética de populações de Aedes aegypti, 156 amostras foram coletadas em dez cidades do estado do Paraná, Brasil. Foi examinada a distribuição dos 311 pares de base do gene que codifica a subunidade 4 da enzima NADH desidrogenase. Pela amplificação e o sequenciamento deste fragmento foram identificados 8 haplótipos distintos. Os valores de diversidade genética foram altos (h = 0.702; p = 0.01556). A análise de AMOVA indicou que a maior variação ocorreu dentro das populações com um valor de FST de 0.32996 altamente significativo. Valores de FST foram significativos na maior das comparações entre as cidades. O isolamento por distância não foi significativo (r = -0.1216 e p = 0.755), indicando que a distância genética não está relacionada a distância geográfica. A análise de Neighbor-joining mostrou dois grupos genéticos distintos dentro do estado do Paraná, grupo I e grupo II. O polimorfismo de DNA e os dados de AMOVA indicam decréscimo de fluxo gênico no estado do Paraná, o que pode resultar em aumento da competência vetorial da população.

Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil). Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil) were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish. Brycon hilarii é uma espécie de peixe migrador, distribuída por toda a Bacia do Paraguai, bastante apreciada tanto pela qualidade da carne quanto para a pesca esportiva, além de ser a principal espécie de interesse turístico da região de Bonito (MS, Brasil). Considerando a ausência de informações sobre a estrutura genética dos peixes desta espécie, o presente trabalho visou detectar a variabilidade genética de Brycon hilarii através de marcadores RAPD. Foi estudado um total de 80 exemplares amostrados em diferentes períodos do ano, em 4 localidades da sub-bacia do Rio Miranda (Bacia do Rio Paraguai, Brasil). Os resultados de similaridade genética, de diversidade de Shanon e AMOVA evidenciaram diferenças entre as localidades amostradas. Através da AMOVA, a diferenciação populacional foi mais evidente entre os peixes coletados no período não-reprodutivo, que representa a época de menor deslocamento desses peixes. Desta forma, ao contrário da idéia até então aceita de que os peixes migradores de água doce formam grandes populações panmíticas em um dado sistema hidrográfico, sugere-se a ocorrência de um modelo de sub-estruturação populacional onde os indivíduos de B. hilarii se organizam em unidades reprodutivas geneticamente diferenciadas e mantêm sua integridade co-existindo e co-migrando através do sistema estudado. Apesar da falta de um cenário completo a respeito da distribuição de B. hilarii na região estudada, esta idéia inicial acerca de sua estrutura genético-populacional pode ser uma contribuição muito importante principalmente por fornecer subsídios para planos de manejo e conservação desses peixes.

Methods to impute HLA alleles based on dense single nucleotide polymorphism (SNP) data provide a valuable resource to association studies and evolutionary investigation of the MHC region. The availability of appropriate training sets is critical to the accuracy of HLA imputation, and the inclusion of samples with various ancestries is an important pre-requisite in studies of admixed populations. We assess the accuracy of HLA imputation using 1000 Genomes Project data as a training set, applying it to a highly admixed Brazilian population, the Quilombos from the state of São Paulo. To assess accuracy, we compared imputed and experimentally determined genotypes for 146 samples at 4 HLA classical loci. We found imputation accuracies of 82.9%, 81.8%, 94.8% and 86.6% for HLA-A, -B, -C and -DRB1 respectively (two-field resolution). Accuracies were improved when we included a subset of Quilombo individuals in the training set. We conclude that the 1000 Genomes data is a valuable resource for construction of training sets due to the diversity of ancestries and the potential for a large overlap of SNPs with the target population. We also show that tailoring training sets to features of the target population substantially enhances imputation accuracy.

NESTE TRABALHO nós usamos o instrumental da genética molecular e da genética de populações para estimar quantitativamente a contribuição africana para a formação do povo brasileiro. Examinamos dois compartimentos genômicos: o DNA mitocondrial, de herança matrilínea, e o DNA nuclear, de herança bi-parental. Os estudos mitocondriais revelaram que aproximadamente 30% dos brasileiros autoclassificados como brancos e 80% dos negros apresentam linhagens maternas características da áfrica subsaariana. A partir destes dados, estimamos que pelo menos 89 milhões de brasileiros são afro-descendentes, um número bem superior aos 76 milhões de pessoas que se declararam negros (pretos e pardos) no censo de 2000 do IBGE. As análises de polimorfismos nucleares com marcadores "informativos de ancestralidade" mostraram resultados mais expressivos ainda. Usando estudos de brasileiros autoclassificados como brancos de várias regiões do Brasil, estimamos que aproximadamente 146 milhões de brasileiros (86% da população) apresentam mais de 10% de contribuição africana em seu genoma. Estes números devem ser levados em conta nas discussões sobre ações afirmativas no Brasil, mas em um sentido descritivo e não prescritivo.IN THIS ARTICLE we used tools of molecular and population genetics to estimate quantitatively the African contribution for the formation of the Brazilian population. We examined two genomic compartments: mitochondrial DNA (mtDNA), maternally inherited, and nuclear DNA, inherited from both parents. The studies using mtDNA showed that about 30% of Brazilians self-classified as White and 80% of Brazilian Negroes carry maternal lineages typical of Sub-Saharan Africa. Using these data we could estimate that at least 89 million Brazilians are afrodescendants, a number considerably larger than the 76 million individuals self-classified as Negro in the 2000 census. The analyses on nuclear polymorphisms employed "ancestry informative" markers and showed even more striking results. On the basis of studies in individuals self-classified as White from several Brazilian regions, we estimated that approximately 146 million Brazilians (86% of the population) had more than 10% African contribution to their genome. These numbers should be taken into account in discussing affirmative action programs in Brazil, but in a descriptive rather than a prescriptive sense.

Background Archaeology reports millenary cultural contacts between Peruvian Coast-Andes and the Amazon Yunga, a rainforest transitional region between Andes and Lower Amazonia. To clarify the relationships between cultural and biological evolution of these populations, in particular between Amazon Yungas and Andeans, we used DNA-sequence data, a model-based Bayesian approach and several statistical validations to infer a set of demographic parameters. Results We found that the genetic diversity of the Shimaa (an Amazon Yunga population) is a subset of that of Quechuas from Central-Andes. Using the Isolation-with-Migration population genetics model, we inferred that the Shimaa ancestors were a small subgroup that split less than 5300 years ago (after the development of complex societies) from an ancestral Andean population. After the split, the most plausible scenario compatible with our results is that the ancestors of Shimaas moved toward the Peruvian Amazon Yunga and incorporated the culture and language of some of their neighbors, but not a substantial amount of their genes. We validated our results using Approximate Bayesian Computations, posterior predictive tests and the analysis of pseudo-observed datasets. Conclusions We presented a case study in which model-based Bayesian approaches, combined with necessary statistical validations, shed light into the prehistoric demographic relationship between Andeans and a population from the Amazon Yunga. Our results offer a testable model for the peopling of this large transitional environmental region between the Andes and the Lower Amazonia. However, studies on larger samples and involving more populations of these regions are necessary to confirm if the predominant Andean biological origin of the Shimaas is the rule, and not the exception. Electronic supplementary material The online version of this article (doi:10.1186/s12862-014-0174-3) contains supplementary material, which is available to authorized users.

The Rufous Gnateater, Conopophaga lineata, is a small insectivorous understory bird which is endemic to and widely distributed in the tropical and subtropical Atlantic forest of South America. Its distribution makes it ideally suited for testing two major hypotheses for the origin of biodiversity, namely, the riverine barrier and the forest refuge hypotheses. In this study, we sequenced mitochondrial (control region) and nuclear markers (intron 5 of the β-fibrinogen gene) for individuals distributed in the southern Atlantic forest and obtained a strong genetic structure with one clear discontinuity in northern Brazilian state of São Paulo. We consistently detected signals of demographic expansion for both markers, with estimates indicating that expansion started in the Late Pleistocene (250,000 years ago), suggesting that the forest refuge hypothesis potentially explains Rufous Gnateater’s diversification. We also found evidence of gene flow between populations from each side of this discontinuity, with a possible secondary contact zone occurring in the states of Minas Gerais, São Paulo, and Rio de Janeiro. Fil: Dantas, Gisele Pires Mendonça. Universidade Federal do Minas Gerais; Brasil. Pontificia Universidad Catolica do Minas Gerais; Brasil Fil: Sari, Eloisa Helena Reis. Universidade Federal do Minas Gerais; Brasil Fil: Cabanne, Gustavo Sebastián. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Pessoa, Rodrigo Oliveira. Universidade de Sao Paulo; Brasil. Universidade Estadual de Montes Claros ; Brasil Fil: Marini, Miguel Angelo. Universidade do Brasilia; Brasil Fil: Miyaki, Cristina Yumi. Universidade de Sao Paulo; Brasil Fil: Santos, Fabricio R.. Universidade Federal do Minas Gerais; Brasil

The destruction of Brazilian natural habitats has reduced bee populations and negative impacts of native flora pollination have been noticed. This work describes the isolation and characterization of microsatellite loci and evaluates them as molecular markers to study genetic variability of the stingless bee Plebeia remota. A microsatellite enriched genomic library was constructed and 15 primer pairs were designed for this species. The survey was conducted by analyzing 21 unrelated individuals. Genetic diversity indexes were calculated. The mean allelic richness was 6.3, the observed heterozygosity was 0.568, and the percentage of polymorphic loci was 93.33%. Also the primers were tested in cross-species amplification and showed promising results for P. droryana, P. emerina, P. lucii, P. meridionalis, P. pugnax, and P. saiqui. The microsatellite loci described here will be useful to evaluate genetic variability of stingless bees, and certainly will improve our knowledge about population dynamics especially in threatened environments.

The Brazilian population represents an admixture of native Amerindians, Portuguese settlers and Africans who were brought as slaves during the colonization period that began in the 16th century and was followed by waves of immigrations of Europeans and Asians in the 20th century. The contribution of these different ethnic groups to the constitution of Brazilian populations from different geographic regions is variable and, in addition to environmental factors, might act by determining different allele profiles among Brazilian populations from different regions. We studied polymorphic sites at the 3' untranslated region of the HLA-G gene in individuals from a Northeastern Brazilian region and compared them to our previously published data about a Southeastern Brazilian region, located at a distance of 2589 km. Our results showed that most polymorphic sites present a similar distribution in both populations, except for the lower frequency of the +3003C allele in the Northeastern population compared to the Southeastern population. Although differences in genotypic distribution were only significant for the +3003 locus (P = 0.0201), the diversity of haplotypes was distinct for each population. These results are important for case-control studies on the association of human leucocyte antigen-G polymorphism with disease and also in terms of the genetic structure of two distinct Brazilian populations.

Epidendrum puniceoluteum is an endemic orchid of Atlantic Rainforest, restricted to few populations only due to the destruction and fragmentation of its native habitat. Here, we report on the development of 10 microsatellite markers isolated from this orchid species. Genetic variability was characterized in two distant populations from Brazil coast. The number of alleles observed for each locus ranged from two to 12 and with an average of 6.4 alleles per locus. These microsatellites should be valuable tools for studying both fine-scale genetic structure of scattered E. puniceoluteum population and patterns will be useful genetic markers for other closely related taxa.

Aedes aegypti (L.) é vetor de importantes doenças como a febre amarela e a dengue, presentes em regiões tropicais e subtropicais. Para o sucesso no seu controle biológico é importante conhecer a estrutura genética e os mecanismos que resultaram na diversidade das populações. O objetivo deste estudo foi analisar a variabilidade genética de diferentes populações de A. aegypti utilizando marcadores de RAPD (Polimorfismo de DNA amplificado ao acaso). DNA de dez larvas coletadas a partir de três populações de diferentes localidades foi analisado usando dez iniciadores de RAPD. Os resultados indicaram a existência de variabilidade genética inter e intrapopulacional. Isso foi confirmado por um dendrograma que agrupou as populações em dois blocos principais com similaridade genética de 24%. Em um desses agrupamentos foi possível distinguir duas populações que apresentaram grau de similaridade de 50%. A diversidade genética entre as populações (55,01%) foi mais elevada que a diversidade genética dentro das populações (44,99%) aplicando-se análise por AMOVA. Altos níveis de polimorfismo genético (Ht = 0.2656) e de diferenciação genética entre as populações (Gst = 0.3689) foram observados. Além disso, o protocolo de extração de DNA adotado mostrou-se eficiente para a análise do inseto independente do seu estágio de desenvolvimento, evitando-se o acréscimo de reagentes ou etapas adicionais de processamento. Futuros experimentos poderão ser realizados para confirmar se a variabilidade observada pode estar ligada às características de resistência de cada população a um determinado pesticida. Aedes aegypti (L.) is an important vector of diseases such as the yellow fever and dengue, present in tropical and subtropical regions. The objective of this study was to analyze the genetic variability of different A. aegypti populations using RAPD (Random Amplified Polymorphic DNA) markers as a basic study to support the use of biocontrol strategies. DNA of ten collected larvae from three different populations were analyzed using ten RAPD primers. The results indicated the existence of genetic variability inter and intrapopulation. This was confirmed by a dendrogram that grouped the populations in two main clusters with a genetic similarity of 24%. In one of these clusters, it was possible to distinguish two populations that showed 50% similarity. The molecular variance analysis indicated that the interpopulation genetic diversity (55,01%) was higher than the intrapopulation genetic diversity (44,99%). A high genetic polymorphism (Ht = 0.2656) and high levels of genetic differentiation between populations (Gst = 0.3689) were found. The adopted DNA extraction protocol proved to be efficient regardless the insect development stage used, avoiding the addition of reagents or additional stages of processing. Future experiments can be performed to confirm if the detected variability is related to the resistance characteristics of each population to a determined pesticide.

The diagnosis and incidence of spinocerebelar ataxias (SCA) is sometimes difficult to analyze due the overlap of phenotypes subtypes and are disorders of mutations caused by CAG trinucleotide repeat expansion. To investigate the incidence of the SCA in Southern Brazil, we analyzed the trinucleotide repeats (CAG)n at the SCA1, SCA2, SCA3, SCA6 and SCA7 loci to identify allele size ranges and frequencies. We examined blood sample from 154 asymptomatic blood donors and 115 individuals with progressive ataxias. PCR products were submitted to capillary electrophoresis. In the blood donors, the ranges of the five loci were: SCA1, 19 to 36 (CAG)n; SCA2, 6 to 28 (CAG)n; SCA3, 12 to 34 (CAG)n; SCA6, 2 to 13 (CAG)n; and SCA7, 2 to 10 (CAG)n. No deviations from Hardy-Weinberg equilibrium were detected. In the ataxia group, we found (CAG)n above the range of the asymptomatic blood donors in SCA3 (21.74%) followed by SCA2 (5.22%), SCA7 (2.61%), SCA6 (0.87%), and no cases of SCA1. The remaining 80 cases (69.56%) have different diagnoses from the type here studied. These data defined the alleles and their frequencies, as well as demonstrated their stability in the population not affected. The molecular diagnosis test confirmed the clinical diagnosis in 28/45 cases and classified another 7/70 from the clinical unclassified ataxias group. A incidência e o diagnóstico das ataxias espinocerebelares (SCA) é algumas vezes difícil de avaliar devido a sobreposição dos diversos subtipos e por algumas serem devido a mutações das expansões do mesmo trinucleotídeo CAG. Para investigar a incidências das SCA no sul do Brasil, analisamos as repetições do trinucleotídeo (CAG)n nos loci das SCA1, SCA2, SCA3, SCA6 e SCA7, a fim de identificar os seus limites e freqüência. Examinamos o sangue de 154 doadores de sangue assintomáticos e 115 pacientes com ataxias progressivas. O produto do PCR do sangue foi submetido a eletroforese capilar. Nos doadores de sangue, as expansões encontradas nos cinco loci foram: SCA1, 19 a 36 (CAG)n; SCA2, 6 a 28 (CAG)n; SCA3, 12 a 34 (CAG)n; SCA6, 2 a 13 (CAG)n; and SCA7, 2 a 10 (CAG)n. Não foi detectado desequilíbrio na equação de Hardy-Weinberg. No grupo das ataxias encontramos repetições CAG acima das freqüências dos doadores de sangue na SCA3 (21,7%), seguido da SCA2 (5,22%), SCA7 (2,61%), SCA6 (0,8%) e não foi encontrado nenhum caso de SCA1. Os 80 casos restantes (69,56%) devem ter uma forma de ataxia diferente das aqui estudadas. Esses dados definem os alelos e suas freqüências, bem como demonstram a sua estabilidade na população não afetada. O diagnóstico molecular confirmou o diagnóstico clínico em 28/45 dos casos e permitiu classificar outros 7/70 que pertenciam ao grupo de ataxias clinicamente não classificadas.

Four Brazilian populations of Anomalocardia brasiliana were tested for mutual genetic homogeneity, using data from 123 sequences of the mtDNA cytochrome oxidase c subunit I gene. A total of 36 haplotypes were identified, those shared being H3 (Canela Island, Prainha and Acupe) and both H5 and H9 (Prainha and Acupe). Haplotype diversity values were high, except for the Camurupim population, whereas nucleotide values were low in all the populations, except for that of Acupe. Only the Prainha population showed a deviation from neutrality and the SSD test did not reject the demographic expansion hypothesis. Fst values showed that the Prainha and Acupe populations represent a single stock, whereas in both the Canela Island and Camurupim stocks, population structures are different and independent. The observed structure at Canela Island may be due to the geographic distance between this population and the remainder. The Camurupim population does not share any haplotype with the remaining populations in northeastern Brazil. The apparent isolation could be due to the rocky barrier located facing the mouth of the Mamanguape River. The results highlight the importance of wide-scale studies to identify and conserve local genetic diversity, especially where migration is restricted.

The formation of the Brazilian Amazonian population has historically involved three main ethnic groups, Amerindian, African and European. This has resulted in genetic investigations having been carried out using classical polymorphisms and molecular markers. To better understand the genetic variability and the micro-evolutionary processes acting in human groups in the Brazilian Amazon region we used mitochondrial DNA to investigate 159 maternally unrelated individuals from five Amazonian African-descendant communities. The mitochondrial lineage distribution indicated a contribution of 50.2% from Africans (L0, L1, L2, and L3), 46.6% from Amerindians (haplogroups A, B, C and D) and a small European contribution of 1.3%. These results indicated high genetic diversity in the Amerindian and African lineage groups, suggesting that the Brazilian Amazonian African-descendant populations reflect a possible population amalgamation of Amerindian women from different Amazonian indigenous tribes and African women from different geographic regions of Africa who had been brought to Brazil as slaves. The present study partially mapped the historical biological and social interactions that had occurred during the formation and expansion of Amazonian African-descendant communities.

Estudos de diversidade e estrutura genética de populações de patógenos por meio de genes de resistência conhecidos são importantes, por permitirem o acesso de forma direta aos genes de virulência/avirulência dos indivíduos das diferentes populações-alvo. Dessa forma, o objetivo deste trabalho foi caracterizar a diversidade e a estrutura genética de três populações de Puccinia coronata f. sp avenae Fraser & Led do Estado do Rio Grande do Sul, por meio da utilização do padrão fenotípico de virulência/avirulência de 40 isolados a 25 genes Pcs. Os resultados obtidos evidenciaram que apesar da elevada variabilidade em virulência dos isolados sul-brasileiros, a população apresenta diversidade genética moderada, principalmente em função da alta virulência dos isolados. Praticamente, não existem diferenças nas freqüências dos genes de virulência nos isolados coletados em Capão do Leão, Eldorado do Sul e Passo Fundo, ou seja, não existe estruturação entre as populações, o que implica na necessidade da adoção de uma estratégia única de controle da moléstia nos três locais. Studies on the genetic diversity and structure of pathogen populations by mean of known resistance genes are important as they allow the direct access to virulence/avirulence genes of individuals in target populations. Therefore, the goal of this work was to characterize the genetic diversity and structure of three Puccinia coronata f. sp avenae Fraser & Led populations from the State of Rio Grande do Sul by using a standard phenotypical assay of virulence/avirulence of 40 isolates to 25 Pcs genes. The results indicated that despite of the high variability for virulence of Southern brazilian isolates, the population showed a moderate genetic diversity, mainly as a function of the high virulence presented by the isolates. Basically, no difference was found in the frequency of virulence genes among the isolates collected in Capão do Leão, Eldorado do Sul and Passo Fundo counties, suggesting that the pathogen populations are not structured. The results indicated the need of a strategy for disease control in these three locations.

O objetivo do presente trabalho foi avaliar a taxa de cruzamento de uma população de Chorisia speciosa por marcadores isoenzimáticos. Foram amostradas sementes de polinização aberta em 28 árvores e tecidos foliares em 53 árvores adultas de uma população de C. speciosa localizada na Estação Ecológica de Bauru, São Paulo, Brasil. Observou-se 18 alelos distribuídos em sete locos polimórficos. O índice de fixação () foi menor nos adultos em relação às progênies, sugerindo seleção contra homozigotos. A estimativa da taxa de cruzamento multilocos () foi de 0,816, revelando que a espécie é de reprodução mista, predominantemente alógama. Foi detectada heterogeneidade no conjunto de pólen dos cruzamentos, indicando que os mesmos não foram aleatórios. Em concordância, a correlação de paternidade () revelou que as progênies são constituídas por uma alta proporção de irmãos completos (71,4%). Foram também detectados cruzamentos entre aparentados na população (5,6%), sugerindo uma possível estruturação espacial em famílias. This study aims to analyse by isozymes the outcrossing rate in a Chorisia speciosa population. Thus, open-pollinated seeds from 28 trees and leaves from 53 adult trees were sampled in a C. speciosa population at the Bauru Ecological Station, São Paulo State, Brazil. Eighteen alleles were observed distributed in seven polymorphic loci. The fixation index () was smaller in adult trees than in families, suggesting selection against homozygous. The multilocus outcrossing estimate () was 0.816, revealed that this species is a mixed mating system, predominantly alogamous. Heterogeneity of pollen pool was observed in outcrossing individual tree indicating that mating were not random. The paternity correlation () revealed that families are constituted of a high proportion of full sibs (71.4%). There was also detection of crossing among relatives in population (5.6%), indicating the possibility of family structure within population.

The intrapopulation fixation index ( f ) is inversely related to the outcrossing rate (t). Results obtained from data on molecular markers of natural populations have shown that these values are highly variable, even when measured in the same group of individuals. It is thus suggested that factors besides those described in Wright's genetic equilibrium must be operating. Using simulated data sets this study shows that the finite size condition of a population is sufficient to spread the estimated f values along a range at equilibrium, as opposed to keeping them at the theoretical equilibrium point. The variation in outcrossing rates can amplify this range considerably. Correlation between estimated f values obtained from different loci in this condition showed to be negatively related to the outcrossing rates, and positively related to the variance of these rates along generations. The finite size of populations associated to small fluctuations in t mean values over time may explain the usually reported high variation among estimated f values of different loci. O fato de que os valores do índice de fixação intrapopulacional ( f ) e os das taxas de fecundação cruzada (t) mantém uma estreita relação entre si é amplamente conhecido. Resultados das análises de marcadores moleculares em populações naturais têm demonstrado uma elevada variação destes valores para locos diferentes avaliados em uma mesma população, sugerindo que outros fatores, além daqueles descritos no modelo de equilíbrio genético de Wright devem estar operando. Pelo uso de simulações, demonstra-se neste trabalho que a condição finita de uma população é suficiente para que os valores estimados de f passem a se estabilizar ao longo de um intervalo de variação e não mais em um único ponto. Demonstra-se ainda que variações nas taxas de fecundação cruzada ao longo das gerações amplificam substancialmente a magnitude deste intervalo. A correlação entre os valores estimados de f obtidos de locos diferentes nestas condições mostrou-se dependente dos valores das taxas de fecundação cruzada e da magnitude da variância destas taxas entre gerações, podendo ser nula sob condições de panmixia e taxas constantes. A condição finita das populações associada a pequenas flutuações na taxa média de fecundação cruzada de diferentes gerações, condições tipicamente encontradas na natureza, podem explicar as discrepâncias entre os valores estimados de f de locos diferentes, comumente reportadas na literatura. Há possibilidade de que a magnitude da variância entre os valores estimados de f de diferentes locos forneça uma estimativa do número efetivo de indivíduos reprodutivamente ativos em uma dada população.

Electrophoretic analysis of presumptive twenty gene loci products was conducted in hemolisates and plasma samples of twenty-eight maned wolves (Chrysocyon brachyurus) from an area in northeastern São Paulo State, Brazil. The area sampled was divided into three sub-areas, with the Mogi-Guaçu and Pardo rivers regarded as barriers to the gene flow. The polymorphism degree and heterozygosity level (intralocus and average) estimated in this study were similar to those detected by other authors for maned wolves and other species of wild free-living canids. The samples of each sub-area and the total sample exhibited genotype frequencies consistent with the genetic equilibrium model. The values of the F-statistics evidenced absence of inbreeding and population subdivision and, consequently, low genetic distances were found among the samples of each area. Os produtos protéicos de 20 locos gênicos foram analisados eletroforeticamente em hemolisados e plasma de 28 lobos-guarás (Chrysocyon brachyurus) de uma área da região Nordeste do Estado de São Paulo, Brasil. A área de estudo foi dividida em 3 subáreas, considerando os rios Mogi-Guaçu e Pardo como barreiras ao fluxo gênico. O grau de polimorfismo e o nível de heterozigosidade (intraloco e média) estimados neste estudo foram semelhantes aos observados por outros autores para lobos-guarás e outras espécies de canídeos de vida livre. As diferentes amostras e a amostra total demonstraram freqüências genotípicas nos locos polimórficos consistentes com o modelo de equilíbrio genético. Os valores da estatística-F evidenciaram ausência de endocruzamento e de estruturação populacional e, como conseqüência, foram encontrados baixos valores de distância genética entre as amostras correspondentes a cada subárea.

The prevalence of metabolic disorders varies among ethnic populations and these disorders represent a critical health care issue for elderly women. This study investigated the correlation between genetic ancestry and body composition, metabolic traits and clinical status in a sample of elderly women. Clinical, nutritional and anthropometric data were collected from 176 volunteers. Genetic ancestry was estimated using 23 ancestry-informative markers. Pearsons correlation test was used to examine the relationship between continuous variables and an independent samples t-test was used to compare the means of continuous traits within categorical variables. Overall ancestry was a combination of European (57.49%), Native American (25.78%) and African (16.73%). Significant correlations were found for European ancestry with body mass index (r = 0.165; p = 0.037) and obesity (mean difference (MD) = 5.3%; p = 0.042). African ancestry showed a significant correlation with LDL (r = 0.159, p = 0.035), VLDL (r = -0.185; p = 0.014), hypertriglyceridemia (MD = 6.4%; p = 0.003) and hyperlipidemia (MD = 4.8%; p = 0.026). Amerindian ancestry showed a significant correlation with triglyceride levels (r = 0.150; p = 0.047) and hypertriglyceridemia (MD = 4.5%; p = 0.039). These findings suggest that genetic admixture may influence the etiology of lipid metabolism-related diseases and obesity in elderly women.