Genetic Studies of the Marine Penaeid Prawn, Penaeus Monodon Fabricius, 1798

The thesis deals with the results of the study of the population characteristics of the marine penaeid prawn, Penaeus monodon from South India. The present findings on the morphometric and biochemical genetic structure support the hypothesis that the populations of P.monodon of South India have homogeneous stock structure. To the contrary, the significantly different random amplified polymorphic DNA (RAPD) profiles in samples of Kochi and Chennai support the hypothesis that east and west cost populations of P.monodon are separate stocks.

Comparative phylogeography of Trypanosoma cruzi TCIIc: New hosts, association with terrestrial ecotopes, and spatial clustering

We characterized 28 new isolates of Trypanosoma cruzi IIc (TCIIc) of mammals and triatomines from Northern to Southern Brazil, confirming the widespread distribution of this lineage. Phylogenetic analyses using cytochrome b and SSU rDNA sequences clearly separated TCIIc from TCIIa according to terrestrial and arboreal ecotopes of their preferential mammalian hosts and vectors. TCIIc was more closely related to TCIId/e, followed by TCIIa, and separated by large distances from TCIIb and TCI. Despite being indistinguishable by traditional genotyping and generally being assigned to Z3, we provide evidence that TCIIa from South America and TCIIa from North America correspond to independent lineages that circulate in distinct hosts and ecological niches. Armadillos, terrestrial didelphids and rodents, and domestic dogs were found infected by TCIIc in Brazil. We believe that, in Brazil, this is the first description of TCIIc from rodents and domestic dogs. Terrestrial triatomines of genera Panstrongylus and Triatoma were confirmed as vectors of TCIIc. Together, habitat, mammalian host and vector association corroborated the link between TCIIc and terrestrial transmission cycles/ecological niches. Analysis of ITS1 rDNA sequences disclosed clusters of TCIIc isolates in accordance with their geographic origin, independent of their host species. (C) 2009 Elsevier B.V. All rights reserved.

Rural Triatoma rubrovaria from Southern Brazil harbors Trypanosoma cruzi of lineage IIc

Triatoma infestans, the main vector of Chagas disease, has nearly been eliminated from Brazil. Nevertheless, other triatominae species are involved in the domiciliation process, including Triatoma rubrovaria in Rio Grande do Sul State (RS). Previous studies showed that 1.6% of the T rubrovaria specimens collected at the rural district of Quarai, RS, were naturally infected by Trypanosoma cruzi. In this study, five T. cruzi isolates obtained from infected triatomines were characterized molecularly and biologically. Genotyping of the T cruzi isolates showed that they belong to lineage IIc of T cruzi (TCIIc). Biological characterization showed miotropism and myositis during acute and chronic phases of infection, respectively. Virulence and mortality rates were variable among isolates. To our knowledge, this study corresponds to the first characterization of T cruzi isolates from T rubrovaria and the first description of TCIIc in the sylvatic cycle of T cruzi from the southern region of Brazil.

Trypanosoma cruzi maxicircle heterogeneity in Chagas disease patients from Brazil

The majority of individuals in the chronic phase of Chagas disease are asymptomatic (indeterminate form, IF). Each year, similar to 3% of them develop lesions in the heart or gastrointestinal tract. Cardiomyopathy (CCHD) is the most severe manifestation of Chagas disease. The factors that determine the outcome of the infection are unknown, but certainly depend on complex interactions amongst the genetic make-up of the parasite, the host immunogenetic background and environment. In a previous study we verified that the maxicircle gene NADH dehydrogenase (mitochondrial complex 1) subunit 7 (ND7) from IF isolates had a 455 bp deletion compared with the wild type (WT) ND7 gene from CCHD strains. We proposed that ND7 could constitute a valuable target for PCR assays in the differential diagnosis of the infective strain. In the present study we evaluated this hypothesis by examination of ND7 structure in parasites from 75 patients with defined pathologies, from Southeast Brazil. We also analysed the structure of additional mitochondrial genes (ND4/CR4, COIII and COII) since the maxicircle is used for clustering Trypanosoma cruzi strains into three clades/haplogroups. We conclude that maxicircle genes do not discriminate parasite populations which induce IF or CCHD forms. Interestingly, the great majority of the analysed isolates belong to T cruzi 11 (discrete typing unit, (DTU) IIb) genotype. This scenario is at variance with the prevalence of hybrid (DTU IId) human isolates in Bolivia, Chile and Argentina. The distribution of WT and deleted ND7 and ND4 genes in T cruzi strains suggests that mutations in the two genes occurred in different ancestrals in the T cruzi 11 cluster, allowing the identification of at least three mitochondrial sub-lineages within this group. The observation that T. cruzi strains accumulate mutations in several genes coding for complex I subunits favours the hypothesis that complex I may have a limited activity in this parasite. (C) 2009 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Caracterização de espécies brasileiras de Adesmia DC. por RAPD

Dentro do gênero Adesmia, as técnicas moleculares ainda não foram empregadas na caracterização de germoplasma e na análise da diversidade genética das espécies brasileiras que compôem o gênero. Portanto os objetivos deste trabalho foram: caracterizar, com a utilização de marcador molecular do tipo RAPD, as espécies brasileiras do gênero Adesmia DC; com base nestas informações estabelecer relações de diversidade genética entre as espécies e os acessos analisados; relacionar dados de diversidade com dados morfológicos e de reprodução.

Variabilidade genética e sensibilidade de acessos de Pistia stratiotes ao herbicida glyphosate

A alface-d'água (Pistia stratiotes) é uma das principais entre as macrófitas aquáticas que causam problemas em corpos hídricos no Brasil e são consideradas como plantas daninhas. O presente trabalho foi realizado com os objetivos de conhecer melhor a variabilidade genética dessa macrófita e relacionar essa variabilidade com a resposta à aplicação do herbicida glyphosate. Para isso, foram coletados indivíduos em 12 corpos hídricos em diferentes cidades do território nacional (Americana, Cambaratiba, Curitiba, Itapura, Jaboticabal, Lagoa Santa, Piraí, Rio Grande, Rubinéia, Salto Grande, Santa Gertrudes e Três Lagoas). Os acessos foram caracterizados pelo uso de marcadores RAPD (DNA Polimórfico Amplificado ao Acaso), que permitiram, com o auxílio de iniciadores aleatórios, a caracterização dos locos polimórficos identificados por uma matriz de ausência e presença de bandas. Utilizando essa matriz, a análise de agrupamento permitiu nítida classificação dos acessos em três grupos com diferenças genéticas entre eles. Um ensaio de controle químico, com plantas mantidas em vasos plásticos (5 L) e pulverizadas com o herbicida glyphosate nas concentrações de 0,0, 0,6, 1,2, 1,8 e 2,4 kg ha-1, identificou, utilizando avaliações aos 7, 14 e 21 dias após aplicação, que as duas maiores doses promoveram melhor efeito herbicida. Foi verificado também que os acessos de Curitiba e Cambaratiba apresentaram menor suscetibilidade ao herbicida glyphosate. Não houve correspondência entre a estrutura de grupos dos acessos pela análise multivariada de agrupamento com a técnica RAPD e a suscetibilidade da alface-d'água ao glyphosate.

Genetic diversity of natural populations of Anemopaegma arvense (Bignoniaceae) in the Cerrado of São Paulo State, Brazil

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

Development of Y-chromosome-Specific SCAR Markers Conserved in Taurine, Zebu and Bubaline Cattle

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

Genetic variations among passion fruit species using rapd markers

Foram avaliadas as variações genéticas através de marcadores moleculares RAPD, as seguintes espécies de maracujá: Passiflora amethystina, P. caerulea, P. cincinnata, P. coccinea, P. serrato digitata, P. foetida, P. maliformis, P. alata, P. giberti, P. laurifolia, P. macrocarpa, P. nitida, P. setacea, P. suberosa, P. ligularis, P. capsularis, P. edulis Sims e sua variedade botânica P. edulis Sims f. flavicarpa Deg. Neste estudo, a análise dos produtos da amplificação ao acaso do DNA polimórfico (RAPD) foi usada para estimar a diversidade genética e as relações taxonômicas entre as espécies. Foram utilizados 21 primers, que produziram um total de 270 bandas polimórficas. Verificou-se que as espécies de Passiflora apresentaram uma média de similaridade de 17,3%, e entre Passiflora edulis Sims e Passiflora edulis Sims f. flavicarpa, de 34,35%. Pode-se perceber que o valor de similaridade dentro da espécie edulis é baixo, ilustrando a grande variação entre a forma amarela e a roxa de Passiflora edulis.

Genetic diversity of two Brazilian populations of the Pampas deer (Ozotoceros bezoarticus, Linnaeus 1758)

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

Morphomolecular characterization of Pleurotus ostreatus (Jacq. Fr.) kummer strains in relation to luminosity and temperature of frutification

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

Molecular typing and antifungal susceptibility of clinical sequential isolates of Cryptococcus neoformans from São Paulo State, Brazil

The antifungal susceptibility profiles and the genetic variability of 83 sequential clinical isolates of Cryptococcus neoformans, including four Cryptococcus gattii isolates, obtained from 38 São Paulo AIDS patients with cryptococcal meningitis were assessed by electrophoretic karyotyping and random amplified polymorphic DNA (RAPD) analysis. The majority of the Cryptococcus neoformans isolates were highly susceptible to amphotericin B and fluconazole. Twenty percent of the minimum inhibitory concentration values for amphotericin B varied from 0.5 to 1 mu g mL(-1). For fluconazole, 22% occurred in the range 8-16 mu g mL(-1). Sequential isolates from nine patients showed a trend towards lower susceptibility to fluconazole, flucytosine, itraconazole and amphotericin B. The results of molecular typing by electrophoretic karyotyping and RAPD analysis showed the presence of 22 electrophoretic karyotypes (EK) and 15 RAPD profiles that were highly correlated. Our results provided evidence for the occurrence of genetic changes in some strains associated with microevolution during the course of infection. We also observed both microevolution and simultaneous coinfection with two distinct Cryptococcus neoformans strains in one patient. In some patients, we found changed EK- and RAPD patterns in association with increased MIC values.

Assessment of genetic relationship between Klebsiella pneumoniae and Klebsiella oxytoca samples isolated from a dental office

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparison of the sequences of the internal transcribed Spacer regions and PbGP43 genes of Paracoccidioides brasiliensis from patients and armadillos (Dasypus novemcinctus)

Paracoccidioides brasiliensis isolates from 10 nine-banded armadillos (Dasypus novemcinctus) were comparable with 19 clinical isolates by sequence analysis of the PbGP43 gene and ribosomal internal transcribed spacer 1 (ITS1) and ITS2 and by random amplified polymorphic DNA. In this original ITS study, eight isolates differed by one or three sites among five total substitution sites.

Genetic polymorphism of Streptococcus mutans in Brazilian family members

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