RESUMO
The genetic variability of 61 Trypanosoma cruzi isolates from 47 chronic chagasic patients of Minas Gerais state was analyzed by random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) using M13-40, lambdagt11-F, and L15996 primers. Cluster analysis by unweighted pair group method analysis was applied to RAPD profiles, and cluster analysis used to verify a possible correlation among different clinical forms of the disease from these patients. The T. cruzi isolates showed distinct grouping on tree topology, with the isolates not being possible to establish a correlation to the clinical forms of Chagas' disease. These data showed that the T. cruzi isolates from these patients would compose a group of populations well correlated genetically.
Assuntos
Doença de Chagas/fisiopatologia , Doença de Chagas/parasitologia , Impressões Digitais de DNA , DNA de Protozoário/genética , Trypanosoma cruzi/classificação , Trypanosoma cruzi/genética , Adulto , Animais , Brasil , Criança , Análise por Conglomerados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Polimorfismo Genético , Técnica de Amplificação ao Acaso de DNA Polimórfico , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
A comparative study of the gene expression profile in different developmental stages of Schistosoma mansoni has been initiated based on the expressed sequence tag (EST) approach. A total of 1401 ESTs were generated from seven different cDNA libraries constructed from four distinct stages of the parasite life cycle. The libraries were first evaluated for their quality for a large-scale cDNA sequencing program. Most of them were shown to have less than 20% useless clones and more than 50% new genes. The redundancy of each library was also analyzed, showing that one adult worm cDNA library was composed of a small number of highly frequent genes. When comparing ESTs from distinct libraries, we could detect that most genes were present only in a single library, but others were expressed in more than one developmental stage and may represent housekeeping genes in the parasite. When considering only once the genes present in more than one library, a total of 466 unique genes were obtained, corresponding to 427 new S. mansoni genes. From the total of unique genes, 20.2% were identified based on homology with genes from other organisms, 8.3% matched S. mansoni characterized genes and 71.5% represent unknown genes.
Assuntos
DNA Complementar/genética , DNA de Helmintos/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Frequência do Gene , Schistosoma mansoni/genética , Animais , Expressão Gênica , Biblioteca Gênica , Dados de Sequência Molecular , Schistosoma mansoni/crescimento & desenvolvimentoRESUMO
Continuing the Schistosoma mansoni Genome Project 363 new templates were sequenced generating 205 more ESTs corresponding to 91 genes. Seventy four of these genes (81%) had not previously been described in S. mansoni. Among the newly discovered genes there are several of significant biological interest such as synaptophysin, NIFs-like and rho-GDP dissociation inhibitor.
