RESUMO
Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantage of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2.770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.
Assuntos
Animais , Mapeamento Cromossômico , Genoma de Protozoário , Trypanosoma cruzi/genética , Cromossomos Artificiais de Levedura , Células Clonais , Sitios de Sequências RotuladasRESUMO
Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.
Assuntos
Mapeamento Cromossômico , Cromossomos Artificiais de Levedura , Cromossomos Bacterianos/genética , Clonagem de Organismos , Genoma de Protozoário , Trypanosoma cruzi/genética , Animais , Biblioteca GenômicaRESUMO
Infection with Trypanosoma cruzi develops in three phases: acute, indeterminate or asymptomatic, and chronic phase (with cardiac or digestive manifestations). Moreover, transmission may occur from infected mothers to newborn, the so-called congenital form. In the present study, humoral responses against T. cruzi total extract and against the 13 amino acid peptide named R-13 derived from the parasite ribosomal P protein, previously described as a possible marker of chronic Chagas heart disease, were determined in chagasic patients and in blood bank donors from endemic areas. While in sera from acute phase, only IgM anti-T.cruzi response was observed, both IgM and IgG anti-T. cruzi antibodies were detected in sera from congenitally infected newborns. The percentage of positive response in sera from blood bank donors was relatively high in endemic regions. Antibodies against the R-13 peptide were present in a large proportion of cardiac chagasic patients but were totally lacking in patients with digestive form of Chagas' disease. Furthermore, anti-R-13 positive responses were detected in congenitally infected newborns.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Doença de Chagas/imunologia , Proteínas de Protozoários , Proteínas Ribossômicas/imunologia , Trypanosoma cruzi/imunologia , Doença Aguda , Animais , Argentina , Sequência de Bases , Doadores de Sangue , Brasil , Cardiomiopatia Chagásica/diagnóstico , Cardiomiopatia Chagásica/imunologia , Doença de Chagas/congênito , Doença de Chagas/epidemiologia , Doença Crônica , Diagnóstico Diferencial , Humanos , Isotipos de Imunoglobulinas/imunologia , Recém-Nascido , Dados de Sequência Molecular , Estudos SoroepidemiológicosRESUMO
The infusion of certain amino acids, such as serine, alanine, and proline (SAP), has been shown to increase the glomerular filtration rate, whereas branched chain amino acids (BCAA) leucine, isoleucine, and valine fail to modify the glomerular filtration rate. It has been suggested that this effect of amino acids on the glomerular filtration rate is mediated by the action of the hormone glomerulopressin. The purpose of this work was to study the action of SAP and BCAA on glomerulopressin production. Livers isolated from rats were perfused with (i) Krebs-Ringer-Bicarbonate, (ii) SAP, or (iii) BCAA. Results indicate that glomerulopressin production is stimulated by SAP, but inhibited by BCAA.
