Polimorfismo genético-molecular de diferentes populações de cateto (Mammalia – Dicotylidae – Tayassu tajacu), Brasil

O estudo de populações naturais é imprescindível para compreendermos melhor a sua dinâmica, importância no ecossistema, necessidade de recursos, nível de preservação das espécies, entre outras. O cateto (Tayassu tajacu), apesar de possuir ampla distribuição geográfica e ocupar diversos tipos de habitats, pode sofrer alterações no equilíbrio de suas populações devido às grandes pressões sofridas pela caça e alterações ambientais. Vale lembrar que o sucesso reprodutivo de muitas espécies vegetais está ligado à disseminação de frutos e sementes realizada pelo cateto. Considerando a necessidade de preservação das espécies silvestres, a aplicação de metodologias moleculares é uma das formas de sabermos como se encontra a diversidade genética dessas populações e, a partir daí, criarmos medidas para trabalhos conservacionistas. Nesse sentido, o objetivo deste trabalho foi identificar o nível de polimorfismo genético-molecular entre diferentes populações de Tayassu tajacu no Brasil, demonstrando como essas populações, sujeitas a tantas interferências, encontram-se na natureza. Foram analisadas amostras de 17 indivíduos referentes a oito localidades do Brasil (Cascavel - PR, Foz do Iguaçu - PR, Cuiabá - MT, Ariquemes - RO, Rio Branco - AC, Manaus - AM, Belém - PA, e Carajás - PR). O polimorfismo foi identificado com marcadores de RAPD. Foram testados 38 primers, sendo que desses apenas nove forneceram as 30 marcas polimórficas para o estudo. Foi possível notar que a maioria dos indivíduos da mesma população ou de populações próximas não são os mais semelhantes entre si. Indivíduos de localidade distantes, como os de Foz de Iguaçu (PR) e Manaus (AM) mostraram-se mais semelhantes entre si do que com os animais das suas próprias populações. A variabilidade entre os indivíduos...(Resumo completo, clicar acesso eletrônico abaixo)

Análise citogenética e investigação molecular do gene RASSF1A em indivíduos com síndrome mielodisplásica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistemática, evolução e biologia reprodutiva de Utricularia com ênfase para Utricularia amethystina Salzm. Ex A.St.-Hil. & Girard (Lentibulariaceae)

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Análise citogenética clássica, molecular e ultraestrutural em escorpiões da família Buthidae: um enfoque evolutivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Papel da hidrofobicidade na evolução de proteínas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uma pesquisa didático-epistemológica na formação inicial em ciências biológicas: como a evolução forjou a grande quantidade de criaturas que habitam o nosso planeta?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo citogenético em aranhas (Mygalomorphae e Araneomorphae) com ênfase na evolução dos genes de DNA ribossômico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Organização cromossômica e molecular do DNAr 5S em duas espécies de gafanhotos do gênero Abracris (Acrididae/Ommatolampidinae)

Os DNAs repetitivos compõem grande porção dos genomas eucariotos e estão organizados em distintos grupos, essencialmente DNAs satélite, microsatélites, minisatélites, elementos de transposição (transposons e retrotransposons) e famílias multigênicas. Estas sequências têm sido úteis nas análises cromossômicas com enfoque em estudos de diversificação cariotípica e de estrutura e evolução dos genomas. Os gafanhotos da família Acrididae representam o grupo com maior diversidade da ordem Orthoptera e apresentam do ponto de vista cromossômico ampla conservação com 2n=23,X0 (macho) na maioria das espécies estudadas. Análises enfocando o entendimento da estrutura das sequências de DNAs repetitivos neste grupo são escassas, e em geral restritas ao mapeamento de algumas famílias multigênicas. Outras sequências repetitivas, tais como DNAs satélites, genes de histonas e DNAr 5S foram realizadas principalmente em espécies de Acridídeos ocorrentes na Europa. No presente trabalho foram isolados e caracterizados do ponto de vista cromossômico e molecular o gene de DNAr 5S e seu espaçador não transcrito (NTS) nas espécies de acridídeos (Ommatolampidinae) Abracris flavolineata e Abracris dilecta. Estas análises permitiram um aprofundamento no conhecimento da estrutura/evolução desta sequência de DNA repetitivo entre as duas espécies, testando-se os possíveis modelos de evolução para esta sequência, que incluem evolução em concerto, nascimento e morte ou modelo misto

Organização cromossômica e molecular do DNAr 5S em duas espécies de gafanhotos do gênero Abracris (Acrididae/Ommatolampidinae)

Os DNAs repetitivos compõem grande porção dos genomas eucariotos e estão organizados em distintos grupos, essencialmente DNAs satélite, microsatélites, minisatélites, elementos de transposição (transposons e retrotransposons) e famílias multigênicas. Estas sequências têm sido úteis nas análises cromossômicas com enfoque em estudos de diversificação cariotípica e de estrutura e evolução dos genomas. Os gafanhotos da família Acrididae representam o grupo com maior diversidade da ordem Orthoptera e apresentam do ponto de vista cromossômico ampla conservação com 2n=23,X0 (macho) na maioria das espécies estudadas. Análises enfocando o entendimento da estrutura das sequências de DNAs repetitivos neste grupo são escassas, e em geral restritas ao mapeamento de algumas famílias multigênicas. Outras sequências repetitivas, tais como DNAs satélites, genes de histonas e DNAr 5S foram realizadas principalmente em espécies de Acridídeos ocorrentes na Europa. No presente trabalho foram isolados e caracterizados do ponto de vista cromossômico e molecular o gene de DNAr 5S e seu espaçador não transcrito (NTS) nas espécies de acridídeos (Ommatolampidinae) Abracris flavolineata e Abracris dilecta. Estas análises permitiram um aprofundamento no conhecimento da estrutura/evolução desta sequência de DNA repetitivo entre as duas espécies, testando-se os possíveis modelos de evolução para esta sequência, que incluem evolução em concerto, nascimento e morte ou modelo misto

Validação de espécies de Centropomus (Centropomidae, Perciformes) do litoral do Rio Grande do Norte através de caracterização citogenética e molecular

The Centropomidae family consists of three genera, Centropomus, Lates and Psammoperca. Centropomus is the most diverse group, with six Centropomus species occur in the Western Atlantic Ocean C. poeyi Chávez, 1961, C. parallelus Poey, 1860, C. mexicanus Bocourt, 1868, C. pectinatus Poey, 1860 and C. ensiferus Poey, 1860. Some of these species are considered cryptic, because of its morphological traits showed low resolution for identification purposes. Despite showing great interest as a natural resource and fish culture, aspects of their diversity and karyotypic patterns are poorly understood. In this work morphological identification and comparison of mitochondrial 16S gene sequence were used to identify the species of the genus Centropomus occurring in Rio Grande do Norte, northeastern Brazil. Two sepecies were identified, C. undecimalis and C. mexicanus, which had the chromosomal aspects analyzed, through Classical cytogenetic method analyzes (conventional staining, C-banding, Ag-NORs), fluorochrome staining AT- and GC-specific, replication bands by incorporating of the base analog 5-Bromo-2’-deoxyuridine (5-BrdU), in situ chromosomal mapping of (TTAGGG)n sequences and in situ chromosome mapping 18S and 5S rRNA genes. Both species show 2n=48 acrocentric chromosomes, with ribosomal sites (Ag-NOR/18S rDNA/ Mitramycin+) in second chromosomal pair, in telomeric position on the long arm in C. mexicanus and interstitial in C. undecimalis. The nuclear organization pair (pair 2) shown a resolutive cytotaxonomic marker for these two species. The generated data reveal a lower species diversity than previously believed, suggesting that greater attention should be paid in taxonomic identification of the species, in view of optimize commercial actions exploitation, biological conservation and cultivation.

Filogenia molecular do gênero Morganella Zeller (Fungi, Basidiomycota) utilizando marcadores ITS

With the development and improvement of techniques for molecular studies and their subsequent application to the systematic, significant changes occurred in the classification of gasteroid fungi. The genus Morganella belongs to the family Lycoperdaceae, and is characterized mainly by lignicolous habit and presence of paracapilicium. Recent data demonstrate the discovery of new species for the group and the existence of a wide variety of species occurring in tropical ecosystems. However, the phylogenetic relationships of the genus, as well as the taxonomic classification, still require revisions to be better understood, the literature studies that address this issue are still very scarce. Thus, the objective of this study was to conduct studies of molecular phylogeny with species of the genus Morganella, to enhance understanding of the phylogeny of the group by including tropical species data. For this, the specimens used both for DNA extractions as for morphological review were obtained from Brazilian and foreign herbaria. For morphological analysis were observed characters relevant to the group's taxonomy. For phylogenetic analysis the Maximum Parsimony and Bayesian Analyzes were used, using the internal transcribed spacer (ITS) of nuclear ribosomal DNA. In phylogenetic analyzes, representatives from Morganella form a monophyletic clade with good support value and based on these results the genus should not be included as subgenus of Lycoperdon. The analysis indicated that M. pyriformis was not grouped with other representatives of Morganella, and therefore should not be included in the group as representative of Apioperdon subgenus because it is a Lycoperdon representative. Moreover, M. fuliginea, M. nuda, M. albostipitata, M. velutina, M. subincarnata are grouped with high support values within the genus Morganella. Morganella arenicola based on morphological and molecular studies does not aggregate in Morganella. Morganella nuda was grouped with M. fuliginea giving indications that can be treated as an intraspecific variation. The results of the analyzes favor to a better understanding of the species of Morganella. However, additional studies using a greater number of species, as well as other molecular markers are needed for a better understanding of the phylogenetic of Morganella.

Infecções por enterobacteriaceae resistente aos carbapenêmicos em hospital de ensino: epidemiologia e caracterização molecular

Introduction: The production of KPC (Klebsiella pneumoniae carbapenemase) has become an important mechanism of carbapenem-resistance among Enterobacteriaceae strains. In Brazil, KPC is already widespread and its incidence has increased significantly, reducing treatment options. The “perfect storm” combination of the absence of new drug developmentand the emergence of multidrug-resistant strains resulted in the need for the use of older drugs, with greater toxicity, such as polymyxins. Aims: To determine the occurrence of carbapenemase-producing strains in carbapenem-resistant Enterobacteriaceae isolated from patients with nosocomial infection/colonization during September/2014 to August/2015, to determine the risk factors associated with 30-day- mortality and the impact of inappropriate therapy. Materials and Methods: We performed a case control study to assess the risk factors (comorbidities, invasive procedures and inappropriate antimicrobial therapy) associated with 30-day-mortality, considering the first episode of infection in 111 patients. The resistance genes blaKPC, blaIMP, blaVIM and blaNDM-1 were detected by polymerase chain reaction technique. Molecular typing of the strains involved in the outbreak was performed by pulsed field gel electrophoresis technique. The polymyxin resistance was confirmed by the microdilution broth method. Results: 188 episodes of carbapenem-resistant Enterobacteriaceae infections/colonizations were detected; of these, 122 strains were recovered from the hospital laboratory. The presence of blaKPC gene were confirmed in the majority (74.59%) of these isolates. It was not found the presence of blaIMP , blaVIM and blaNDM-1 genes. K. pneumoniae was the most frequent microorganism (77,13%), primarily responsible for urinary tract infections (21,38%) and infections from patients of the Intensive Care Unit (ICU) (61,38%). Multivariate statistical analysis showed as predictors independently associated with mortality: dialysis and bloodstream infection. The Kaplan-Meier curve showed a lower probability of survival in the group of patients receiving antibiotic therapy inappropriately. Antimicrobial use in adult ICU varied during the study period, but positive correlation between increased incidence of strains and the consumption was not observed. In May and July 2015, the occurrence rates of carbapenem-resistant Enterobacteriaceae KPC-producing per 1000 patient-days were higher than the control limit established, confirming two outbreaks, the first caused by colistin-susceptible KPC-producing K. pneumoniae isolates, with a polyclonal profile and the second by a dominant clone of colistin-resistant (≥ 32 μg/mL) KPC-producing K. pneumoniae. The cross transmission between patients became clear by the temporal and spatial relationships observed in the second outbreak, since some patients occupied the same bed, showing problems in hand hygiene adherence among healthcare workers and inadequate terminal disinfection of environment. The outbreak was contained when the ICU was closed to new admissions. Conclusions: The study showed an endemicity of K. pneumoniae KPC-producing in adult ICU, progressing to an epidemic monoclonal expansion, resulted by a very high antibiotic consumption of carbapenems and polymyxins and facilitated by failures in control measures the unit.

Molecular And Biochemical Characterization Of Caffeine Synthase And Purine Alkaloid Concentration In Guarana Fruit.

Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.

On The Distinct Molecular Architectures Of Dipping- And Spray-lbl Films Containing Lipid Vesicles.

The introduction of spraying procedures to fabricate layer-by-layer (LbL) films has brought new possibilities for the control of molecular architectures and for making the LbL technique compliant with industrial processes. In this study we show that significantly distinct architectures are produced for dipping and spray-LbL films of the same components, which included DODAB/DPPG vesicles. The films differed notably in their thickness and stratified nature. The electrical response of the two types of films to aqueous solutions containing erythrosin was also different. With multidimensional projections we showed that the impedance for the DODAB/DPPG spray-LbL film is more sensitive to changes in concentration, being therefore more promising as sensing units. Furthermore, with surface-enhanced Raman scattering (SERS) we could ascribe the high sensitivity of the LbL films to adsorption of erythrosin.

Albumin Is Synthesized In Epididymis And Aggregates In A High Molecular Mass Glycoprotein Complex Involved In Sperm-egg Fertilization.

The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb) TRA 54. Immunohistochemical and immunoblotting analyses suggest that the epitope of the epididymal antigen probably involves a sugar moiety that is released into the epididymal lumen in an androgen-dependent manner and subsequently binds to luminal sperm. Using column chromatography, SDS-PAGE with in situ digestion and mass spectrometry, we have identified the protein recognized by mAb TRA 54 in mouse epididymal epithelial cells. The ∼65 kDa protein is part of a high molecular mass complex (∼260 kDa) that is also present in the sperm acrosomal vesicle and is completely released after the acrosomal reaction. The amino acid sequence of the protein corresponded to that of albumin. Immunoprecipitates with anti-albumin antibody contained the antigen recognized by mAb TRA 54, indicating that the epididymal molecule recognized by mAb TRA 54 is albumin. RT-PCR detected albumin mRNA in the epididymis and fertilization assays in vitro showed that the glycoprotein complex containing albumin was involved in the ability of sperm to recognize and penetrate the egg zona pellucida. Together, these results indicate that epididymal-derived albumin participates in the formation of a high molecular mass glycoprotein complex that has an important role in egg fertilization.