>Magister Scientiae - MSc / Sea anemones (Order Actinaria) are a diverse order from the Class Anthozoa. They are found in all marine habitats at all depths and their symbiotic relationships play an important role in energy transfers especially in the benthic-pelagic community. The evolutionary background and phylogenetics of the class is poorly understood due to a lack of correspondence between taxonomic and molecular data (Daly et al. 2008). Therefore, a deeper exploration into Cnidarian molecular biology is needed to establish these as an evolutionary model organism. Gene discovery from various marine invertebrates has facilitated the recovery of anti-cancer drugs, antibiotics and reporter genes (Faulkner, 2000; Allen and Jaspars, 2009). The most commercially lucrative products from sea anemones are fluorescent and chromoproteins (FP/CP), which are used as non-invasive real-time reporter genes. The applications for these proteins are extensive and range from monitoring cellular processes such as protein localisation and interactions to imaging (Alieva et al. 2008). Therefore, novel FP and CPs have potential for commercialization. The aims of the project were to analyze basic molecular diversity of the sea anemones Pseudactinia varia, Pseudactina flagellifera and Bunodosoma capensis and evaluate a new screening method to isolate novel FP and CPs. To assess the basic molecular diversity, of the sea anemones and their associated symbionts 16S rRNA and 18S rRNA clone libraries were generated. The sea anemones used in this study clustered together with those of the Family Actiniidae. The bacterial associations observed based on the closest relative BLAST analysis were dominated by Proteobacteria (gamma, alpha and epsilon) as well as Bacteroides. The associate bacterial symbionts possibly produce compounds that range from polyunsaturated fatty acids, polyhydroxyalkanoates to anti-microbial compounds that aid the host in various processes. In order to screen for FPs and CPs from sea anemones three types of cDNA libraries were generated to be screened either by sequence based or activity based approaches. Novel primers were designed which could be applied for the screening of a variety of Anthozoans. A positive control was also designed and synthesised in order to test the capability of the designed primers and optimise the amplification. Although amplicons were generated from gDNA and cDNA libraries from each of the sea anemones they were found to be non-specific products. The detection limit is likely to be the limiting factor. The construction of an activity based library was not achieved due to technical constraints, which highlights the need for new molecular tools in this field or improvements to the existing ones. / National Research Foundation (NRF)

Small-molecule libraries with enhanced structural diversity are of value in drug discovery campaigns where novel biologically active hits are desired. As such, multicomponent reactions (MCRs) have proven fruitful to enhance the molecular diversity of chemical collections and expedite forward progression of the drug discovery chain. Bicalutamide (Casodex), an anticancer drug, and Telaprevir (Incivek), an antiviral, are two examples of marketed drugs that can be synthesized using an MCR. The research topic of this dissertation involves the design, discovery, and development of novel MCRs and new combinations of MCRs with post-condensation modifications to generate over twenty-five new drug-like scaffolds in an operationally friendly, atom-economical, time- and cost-effective fashion. The developed chemical methodologies possess inherent 'iterative efficiency','high exploratory power', and 'bond forming efficiency' that allow them to quickly explore chemical space and navigate the 'hypothesis-synthesis-screening' loop that is key for a medicinal chemistry project. The prepared molecules were submitted to the Community for Open Antimicrobial Drug Discovery (CO-ADD) for antimicrobial screening against pathogens that are known to cause drug-resistance infections.

Circovirus suíno 2 (PCV2) associado a doenças (PCVAD do inglês Porcine circovirus associated disease) pode se manifestar como infecção sistêmica, enterite, problemas reprodutivos, síndrome de dermatite e nefropatia suína e complexo de doenças respiratórias (PRDC). A ocorrência de PRDC, que afeta, principalmente, animais de crescimento e terminação, caracteriza-se por crescimento lento, tosse prolongada e dispnéia, assim como lesões macroscópicas características em pulmão. PCV2 possui três principais regiões abertas de leitura (ORFs): ORF-1 codifica proteínas envolvidas na replicação (gene Rep); ORF-2 codifica proteína estrutural do capsídeo (gene Cap) e ORF-3 codifica proteína envolvida na indução de apoptose celular. O gene Cap é a região mais variável do PCV2, havendo indícios da associação entre a proteína Cap e patogenicidade. De acordo com a nomenclatura unificada proposta por Segalés et al., três diferentes genótipos são atualmente reconhecidos (PCV2a, - 2b, -2c). O aumento na incidência e gravidade da PCVAD foi atribuído ao surgimento do PCV2b tornando-se o mais prevalente subtipo em países da América do Norte, Europa, e no Brasil. Diante dos prejuízos que a PRDC acarreta, 200 amostras de pulmão com e sem lesões pneumônicas macroscópicas foram analisadas para PCV2 pela PCR; 88,5 % (177/200) foram positivas para PCV2 por PCR corroborando com estudos em que o PCV2 foi encontrado em um grande numero de amostras e poderia desenvolver um papel da PRDC. Entretanto, não houve associação significativa entre amostras positivas e presença ou ausência de lesões pneumônicas macroscópicas (p=0,26). A análise filogenética de 27 amostras PCV2 positivas sequênciadas (22 genoma completo e cinco ORF-2 completa) foram agrupadas no genótipo PCV2b. Devido à alta identidade de nucleotídeos e aminoácidos entre as sequencias obtidas e as recuperadas de estudos anteriores com presença e ausência de PCVAD, não há indícios de associação entre patogenicidade e o subtipo de PCV2 identificado neste trabalho / Porcine circovirus 2 (PCV2) associated disease (PCVAD) may manifest as systemic infection, enteritis, reproductive problems, dermatitis and nephropathy syndrome and porcine respiratory disease complex (PRDC). The occurrence of PRDC, which affects mainly the growing and finishing animals, characterized by slow growth, prolonged cough and dyspnea, as well as characteristic gross lesions in the lungs. PCV2 has three main regions denominated open reading frames (ORFs): ORF-1 encodes a protein involved in replication (Rep gene), ORF-2 encodes the capsid structural protein (Cap gene) and ORF-3 encodes a protein involved in the induction of cellular apoptosis. The Cap gene is the most variable region of PCV2, with evidence of association between the Cap protein and pathogenicity. According to an unified nomenclature proposed by Ségales et al., three different subtypes are currently recognized (PCV2a,-2b-2c). The increased incidence and severity of PCVAD was attributed to the rise of PCV2b becoming the most prevalent subtype in countries of North America, Europe, and Brazil. Given the damage that leads to PRDC, 200 samples of lungs with and without macroscopic pneumonic lesions were analyzed for PCV2 by PCR; 88.5% (177/200) were positive for PCV2 by PCR corroborating with studies in which PCV2 was found in a large number of samples and could develop a role in PRDC. However, there was no significant association between positive samples and the presence or absence of macroscopic pneumonic lesions (p=0.26). Phylogenetic analysis of the 27 samples PCV2 positive sequenced (22 complete genome and five complete ORF-2) were grouped in genotype PCV2b. Due to the high identity between the nucleotide and amino acid sequences obtained and retrieved from previous studies with presence and absence of PCVAD, there is no evidence of association between subtype and pathogenicity of PCV2 identified in this work

Operationally friendly protocols to produce libraries of novel small molecules with high molecular complexity are in huge demand for the interrogation of biological systems. As such, development of new MCRs and post-condensation modification of the MCR products have proven fruitful in the quest for new molecular probes and their expedited progression along the drug discovery value chain. The products thereof have found their way into numerous corporate compound collections. Crixivan (Indinavir), an antiretroviral, and Xylocaine (Lidocaine), a local anesthetic, are two examples of drugs derived from an MCR that have been marketed. The research topic of this dissertation encompasses the design and development of fifteen novel drug-like chemotypes in an operationally friendly, green, and expedited (≤ 3 synthetic operations) manner involving the Ugi MCR coupled with MAOS and high-throughput purification platforms. Over 500 drug-like small molecules (purity > 90% based on UV 214 nm and ELSD) have been synthesized, purified, and submitted to the NIH MLSMR for further biological evaluation against protein targets of interest. Furthermore, non-electrochemical carbamate oxidations enabling formation of N-acyliminium ion precursors, which are reactive intermediates that form the basis of a multitude of synthetic routes to natural products, have also been developed.

Tardigrades can handle extreme conditions such as heat, cold and drought, thanks to a process called cryptobiosis which can be found in a limited amount of taxa on Earth. More knowledge about such animals may help us to understand the potential and limitations of life both on Earth and possibly in space. Such knowledge may also help develop novel, useful applications for the society, such as better storage of sensitive medicine. However, our knowledge about tardigrades is limited. We know little about their distribution and diversity, especially in Sweden, and above all in northern Sweden. The aim of this study was threefold; i) to explore the biogeography of the tardigrades based on molecular data; ii) to screen for tardigrades in Umeå by examining moss samples from different locations; and iii) to explore some of the associates of tardigrades in moss (such as bacteria and micro- and meiofauna). The biogeography was explored by collecting all published ribosomal gene sequences (the small subunit 18S rRNA) from the Silva gene database. These sequences were used for plotting the locations from which these gene sequences had been retrieved on a world map and the correlation between gene sequence, country and biotope was examined. The tardigrade groups most sequenced are Macrobiotus, Ramazottius and Echiniscus, and the milieu most studied seems to be different types of soil. Other investigated isolation sources are drinking water, cryconite and church walls. However, much remains to be further explored. For example, the world map showed that the only molecular data on Swedish tardigrades have been retrieved from Öland. In the lab, tardigrades were found in some of the moss samples, together with other micro- and meiofauna. Three groups of bacteria (Betaproteobacteria, Gammaproteobacteria and Firmicutes) could be identified in one of the investigated mosses. These results suggest that tardigrades live in a diverse environment with different types of organisms both on the microbial as well as on the micro-meio-fauna level.

Circovirus suíno 2 (PCV2) associado a doenças (PCVAD do inglês Porcine circovirus associated disease) pode se manifestar como infecção sistêmica, enterite, problemas reprodutivos, síndrome de dermatite e nefropatia suína e complexo de doenças respiratórias (PRDC). A ocorrência de PRDC, que afeta, principalmente, animais de crescimento e terminação, caracteriza-se por crescimento lento, tosse prolongada e dispnéia, assim como lesões macroscópicas características em pulmão. PCV2 possui três principais regiões abertas de leitura (ORFs): ORF-1 codifica proteínas envolvidas na replicação (gene Rep); ORF-2 codifica proteína estrutural do capsídeo (gene Cap) e ORF-3 codifica proteína envolvida na indução de apoptose celular. O gene Cap é a região mais variável do PCV2, havendo indícios da associação entre a proteína Cap e patogenicidade. De acordo com a nomenclatura unificada proposta por Segalés et al., três diferentes genótipos são atualmente reconhecidos (PCV2a, - 2b, -2c). O aumento na incidência e gravidade da PCVAD foi atribuído ao surgimento do PCV2b tornando-se o mais prevalente subtipo em países da América do Norte, Europa, e no Brasil. Diante dos prejuízos que a PRDC acarreta, 200 amostras de pulmão com e sem lesões pneumônicas macroscópicas foram analisadas para PCV2 pela PCR; 88,5 % (177/200) foram positivas para PCV2 por PCR corroborando com estudos em que o PCV2 foi encontrado em um grande numero de amostras e poderia desenvolver um papel da PRDC. Entretanto, não houve associação significativa entre amostras positivas e presença ou ausência de lesões pneumônicas macroscópicas (p=0,26). A análise filogenética de 27 amostras PCV2 positivas sequênciadas (22 genoma completo e cinco ORF-2 completa) foram agrupadas no genótipo PCV2b. Devido à alta identidade de nucleotídeos e aminoácidos entre as sequencias obtidas e as recuperadas de estudos anteriores com presença e ausência de PCVAD, não há indícios de associação entre patogenicidade e o subtipo de PCV2 identificado neste trabalho / Porcine circovirus 2 (PCV2) associated disease (PCVAD) may manifest as systemic infection, enteritis, reproductive problems, dermatitis and nephropathy syndrome and porcine respiratory disease complex (PRDC). The occurrence of PRDC, which affects mainly the growing and finishing animals, characterized by slow growth, prolonged cough and dyspnea, as well as characteristic gross lesions in the lungs. PCV2 has three main regions denominated open reading frames (ORFs): ORF-1 encodes a protein involved in replication (Rep gene), ORF-2 encodes the capsid structural protein (Cap gene) and ORF-3 encodes a protein involved in the induction of cellular apoptosis. The Cap gene is the most variable region of PCV2, with evidence of association between the Cap protein and pathogenicity. According to an unified nomenclature proposed by Ségales et al., three different subtypes are currently recognized (PCV2a,-2b-2c). The increased incidence and severity of PCVAD was attributed to the rise of PCV2b becoming the most prevalent subtype in countries of North America, Europe, and Brazil. Given the damage that leads to PRDC, 200 samples of lungs with and without macroscopic pneumonic lesions were analyzed for PCV2 by PCR; 88.5% (177/200) were positive for PCV2 by PCR corroborating with studies in which PCV2 was found in a large number of samples and could develop a role in PRDC. However, there was no significant association between positive samples and the presence or absence of macroscopic pneumonic lesions (p=0.26). Phylogenetic analysis of the 27 samples PCV2 positive sequenced (22 complete genome and five complete ORF-2) were grouped in genotype PCV2b. Due to the high identity between the nucleotide and amino acid sequences obtained and retrieved from previous studies with presence and absence of PCVAD, there is no evidence of association between subtype and pathogenicity of PCV2 identified in this work

No description available.

Les sols pollués par des métaux lourds sont colonisés par des communautés de microorganismes qui ont développé différentes adaptations leur permettant de résister à ces contaminants. Afin d'analyser au niveau moléculaire la diversité de ces adaptations, une approche expérimentale innovante basée sur l'étude du méta transcriptome eucaryote des sols a été utilisée pour comparer les fonctions exprimées au sein d'une communauté de microorganismes eucaryotes colonisant un sol contaminé, anciennement contaminé et non contaminé par des métaux lourds. Les banques d’ADNc eucaryotes construites à partir des ARNm extraits directement de ces sols ont été criblées par séquençage aléatoire de leurs inserts et par complémentation fonctionnelle de mutants de levures sensibles au cadmium.Cette étude a permis d’identifier de nouveaux gènes et de nouveaux mécanismes impliqués dans la résistance au cadmium ainsi qu’un nombre important de nouvelles protéines hypothétiques. Ceci démontre l’intérêt appliqué de cette approche pour la recherche de nouveaux bio catalyseurs et molécules bio actives.En parallèle, la diversité microbienne eucaryote a été révélée et comparée entre les sols par le clonage-séquençage du gène codant la petite sous-unité ribosomique 18S. Cette étude a mis en évidence une diversité inattendue de microorganismes eucaryotes dans ces sols et une analyse phylogénétique a permis de découvrir un nouveau clade de protistes (Rhizaria,Cercozoa). / Heavy metal-polluted soils are colonised by microbial communities which have developed different adaptations that allow them to resist to these pollutants. The objectives of this study were to reveal at the molecular level the diversity of these adaptations. To this aim,we implemented an innovative approach based upon the analysis of soil eukaryotic metatranscriptome to compare resistance mechanisms expressed by eukaryotic microorganisms living in heavy metal contaminated and control non contaminated or formerly-contaminated soils. Eukaryotic cDNA libraries were prepared using mRNA directly extracted from these soils and screened by either systematic sequencing of their inserts or functional complementation of yeast mutants sensitive to cadmium. This study allowed us to characterise novel genes and mechanisms implicated in Cd resistance as well as numerousnovel hypothetical proteins. This study also demonstrates the potential of this experimental approach to look for novel biocatalysts as well as novel bio-active molecules.In addition, eukaryotic molecular diversity was studied by the cloning-sequencing of the gene encoding the 18S ribosomal RNA. This study revealed an unexpected diversity of eukaryotic diversity in the studied soils and allowed us to discover a novel clade of protists(Rhizaria, Cercozoa).

Coronavírus, incluindo-se o Coronavírus aviário (ACoV), possuem o maior genoma composto por RNA conhecido entre os vírus. Aproximadamente dois terços desse genoma codificam proteínas não estruturais (Nsps), cujas funções parecem estar associadas à replicação e patogênese viral. Até o momento, esses alvos têm sido pouco explorados quanto a sua diversidade em diferentes linhagens de ACoV. O presente estudo teve como objetivo investigar a diversidade dos genes codificadores das proteínas não estruturais Nsp2 e protease Papaína-like (Plpro), utilizando-se linhagens brasileiras de ACoV. Para tanto, 10 linhagens de ACoV, isoladas em ovos embrionados, foram submetidas à RT-PCR direcionada aos genes codificadores de Plpro e Nsp2, seguindo-se o sequenciamento de DNA e a análise filogenética, juntamente com sequências homólogas obtidas no GenBank. Além disso, realizou-se a genotipagem por meio do sequenciamento parcial do gene codificador da proteína de espícula (região S1). Três das amostras virais obtidas e investigadas no presente trabalho apresentaram padrão de segregação discordante para os genes estudados. O isolado CRG I22 agrupou-se com linhagens virais pertencentes ao genótipo Massachusetts para S1 e com o grupamento de ACoVs brasileiros os genes da Nsp2 e Plpro. O isolado CRG I33 agrupou-se com linhagens virais pertencentes ao genótipo brasileiro para s1 e plpro e de maneira divergente para o gene da Nsp2. Para o isolado CRG I38, não foi obtida a genotipagem por s1, entretanto, similarmente ao observado para o isolado CRG I33, esse isolado agrupo-se com linhagens virais brasileiras para o gene plro e de maneira independente para o gene nsp2. As demais linhagens estudadas resultaram na formação de um grupamento especificamente brasileiro de ACoV, para os três genes estudados. Esses achados sugerem a ocorrência de recombinação nessas amostras discrepantes. Quanto às identidades médias entre as sequencias nucleotídicas analisadas, a região de s1 analisada apresentou as menores identidades (73,75% ±16,78), seguido pelo gene plpro (88,06% ±5,7) e do gene nsp2 (92,28% ±4,37), em acordo com a literatura. Assim sendo, os alvos investigados podem constituir ferramentas úteis na epidemiologia molecular do ACoV e na investigação de linhagens recombinantes do vírus. O presente estudo é o primeiro a investigar a diversidade genética de genes codificadores de proteínas não-estruturais em linhagens brasileiras de ACoV. Os resultados aqui apresentados reforçam a existência de um genótipo brasileiro de ACoV, para os 3 genes estudados. Entretanto, discrepâncias pontuais encontradas no padrão genotípico para s1, nsp2 e nsp3 permitem inferir uma diversidade genética maior do que a conhecida até o momento, possivelmente resultante de eventos de recombinação entre ACoVs brasileiros, ACoVs vacinais e outros ainda desconhecidos. Os resultados obtidos auxiliam na compreensão dos padrões e evolução dos ACoVs / Coronaviruses, including Avian coronavirus (ACoV), have the largest known RNA genome. Nearly two thirds of its genome codes for non-structural proteins (Nsps), whose functions appear to be linked to viral replication and pathogenesis. Hitherto these targets have been poorly explored regarding the ACoV lineages diversity. The present study aimed to assess the diversity of non-structural protein 2 (nsp2), papain-like protease (plpro) and spike protein (S1 subunit) coding genes, in Brazilian ACoV strains. To this end, 10 ACoV strains, isolated in embryonated eggs, had its 3rd and 5th passages submitted to RT-PCR targeting nsp2, plpro and s1, followed by DNA sequencing and phylogenetic analysis, herewith homologous sequences obtained from GenBank. Three of the ACoV strains sequenced showed a discordant segregation pattern for target genes. CRG I22 strain clustered with Massachusetts genotipe strains for S1, and with Brazilian cluster for nsp3 and plpro genes. CRG I33 strain, clustered with Brazilian strains for S1 and plpro genes, and was divergent for nsp2 gene. For CRG I38 strain, the S1 sequence was not obtained, however, similarly to what was observed for CRG I33, this strain grouped with the Brazilian lineage for plpro gene and was divergent for nsp2 gene. All the other ACoV here sequenced resulted in a specific Brazilian cluster for the three studied genes. Regarding the mean nucleotide identities measured, s1 gene showed the lowest identity (73.75% ±16.78), followed by plpro gene (88.06% ±5.7) and nsp2 gene (92.28% ±4.37), in accordance with previous reported data. Therefore, the targets of the present study are useful tools for ACoV molecular epidemiology studies and for the survey of recombinant ACoV strains. The presented study is the first one investigating the molecular diversity of non-structural proteins coding genes in Brazilian strains of ACoV. Results achieved herein reinforce the data over the circulation of ACoV Brazilian strains in this country, for the three investigated genes. However, divergences found between S1, nsp2 and plpro genetic patters allow inferring a higher molecular diversity than previously known. It is possible that this divergence is due to recombination events between ACoV from vaccines, Brazilian field strains and others still unknown. These results contribute on the comprehension over genetic patters and evolution of ACoV

Submitted by Natalia de Souza Gonçalves (natalia.goncalves@ufpe.br) on 2016-09-23T13:21:33Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Diversidade cromossômica e molecular de gafanhotos neotropicais_Tese_Tyago Eufrásio de Souza_2016.pdf: 5140522 bytes, checksum: a3f59c2f3fae3b977e8e585c0f3ff493 (MD5) / Made available in DSpace on 2016-09-23T13:21:33Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Diversidade cromossômica e molecular de gafanhotos neotropicais_Tese_Tyago Eufrásio de Souza_2016.pdf: 5140522 bytes, checksum: a3f59c2f3fae3b977e8e585c0f3ff493 (MD5) Previous issue date: 2016-03-03 / CAPES / Nos últimos anos, alguns estudos de mapeamento cromossômico foram realizados em gafanhotos do grupo Acridomorpha, preferencialmente através do uso de sondas de sequências repetitivas. Este trabalho tem como objetivo contribuir para uma melhor compreensão dos aspectos cromossômicos evolutivos em gafanhotos acridomorfos e da diversidade genética de Ommexecha virens. Os genes de cópia única Hsp83, Hsp70, Hsp27, Ubi, Lys foram localizados nos cromossomos meióticos de Ommexecha virens, Xyleus discoideus angulatus, Tropidacris collaris e Stiphra robusta e Lys em Schistocerca pallens através de Hibridização in situ permanente (PISH). Sequências repetitivas de rDNA 45S, rDNA 5S e Histona H3 foram localizadas em O virens através de Hibridização in situ fluorescente (FISH). Em O. virens também foi analisado o cromossomo B por técnicas convencionais, diferenciais e moleculares, bem como a estrutura genética de oito populações naturais (seis de Pernambuco, uma da Bahia e uma do Ceará) do Nordeste brasileiro com o marcador ISSR (regiões entre sequências de repetições simples). Os genes de cópia única apresentaram um padrão conservado de localização em pares cromossômicos grandes, preferencialmente o L1, exceto para Hsp70 e Ubi, localizados no L2. Sinais secundários foram observados em cromossomos médios. A conservação apresentada deve-se a ausência ou pequena ocorrência de rearranjos nos cromossomos destes cariótipos, o que reduz o risco de eventos deletérios, bem como pela localização coincidente com regiões ricas em heterocromatina constitutiva. A conservação da localização destes genes indicou os cromossomos portadores dos locus gênicos ancestrais para os genes mapeados. O estudo do cromossomo B em O. virens revelou similaridade de tamanho e marcação CMA3 positiva com o cromossomo 9, sugerindo a possível origem deste cromossomo. Contudo, a presença de sítios de rDNA 45S e Histona H3 no cromossomo 9 e ausência no B, provavelmente pela deleção dessas sequências neste cromossomo, não permitem descartar a possibilidade do B ter se originado de outro cromossomo. A análise genética populacional em O. virens mostrou três cluster, os quais exibiram relação com aspectos da biologia da espécie, a paisagem dos ambientes amostrados e com as modificações geológicas ocorridas no Nordeste brasileiro, em particular a formação do complexo da Borborema e a Chapada do Araripe. / In recent years, some chromosomal mapping studies were performed in Acridomorpha group grasshoppers, preferably through the use of repetitive sequence probes. In this work in order to contribute to a better understanding of evolutionary chromosomal aspects of acridomorphs and genetic diversity of Ommexecha virens. The single copy genes Hsp83, Hsp70, Hsp27, Ubi, Lys were located in meiotic chromosomes of Ommexecha virens, Xyleus discoideus angulatus, Tropidacris collaris and Stiphra robusta, and Lys in Schistocerca pallens through permanent situ hybridization (PISH). Repetitive sequences of 45S rDNA, 5S rDNA and H3 histone were located in the O. virens via fluorescent in situ hybridization (FISH). In O. virens was also analyzed the B chromosome by conventional, differential and molecular techniques and genetic structure of eight natural populations (six of Pernambuco, one of Bahia and one of Ceará) of the Northeast of Brazil with ISSR marker (inter simple sequence repeat). Single copy genes showed a conserved pattern of location in large chromosomal pairs, preferably L1, except for Hsp70 and Ubi, located in L2. Secondary signals were observed on medium chromosomes. The presented conservation due to absence or occurrence of small rearrangements in these karyotypes, which reduces the risk of deleterious events as well as for matching location with regions rich in heterochromatin. The conservation of the location of these genes indicated the chromosomes carrying the genic locus ancestors to the mapped genes. The study of B chromosome of O. virens revealed similarity in size and CMA3 positive marking to chromosome 9, suggesting the possible origin of this chromosome. However, the presence of 45S rDNA sites and H3 histone on chromosome 9 and the absence on B, probably due to deletion of these sequences in this chromosome, do not allow to rule out the possibility of B have originated from another chromosome. Population genetic analysis O. virens showed three clusters, which exhibited relationship with aspects of the biology of the species, the landscape of the study sites and the geological changes occurred in northeastern of Brazil, in particular the formation of the Borborema and Araripe plateaus.