RESUMEN
The genetic variation among nine soybean-originating isolates of Colletotrichum truncatum from different Brazilian states was studied. Nitrate non-utilizing (nit) mutants were obtained with potassium chlorate and used to characterize vegetative compatibility reactions, heterokaryosis and RAPD profile. Based on pairings of nit mutants from the different isolates, five vegetative complementation groups (VCG) were identified, and barriers to the formation of heterokaryons were observed among isolates derived from the same geographic area. No complementation was observed among any of the nit mutants recovered from the isolate A, which was designed heterokaryon-self-incompatible. Based on RAPD analysis, a polymorphism was detected among the wild isolate C and their nit1 and NitM mutants. RAPD amplification, with five different primers, also showed polymorphic profiles among Brazilian C. truncatum isolates. Dendrogram analysis resulted in a similarity degree ranging between 0.331 and 0.882 among isolates and identified three RAPD groups. Despite the lack of a correlation between the RAPD analysis and the vegetative compatibility grouping, results demonstrated the potential of VCG analysis to differentiate C. truncatum isolates genotypically similar when compared by RAPD.
Asunto(s)
Colletotrichum/genética , Variación Genética/genética , Glycine max/microbiología , Mutación/genética , Brasil , Colletotrichum/clasificación , Colletotrichum/aislamiento & purificación , Genotipo , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
The recombinogenic potential of fluoxetine, an antidepressant widely prescribed in the treatment of depressive disorders in cancer patients, was investigated in this study. A heterozygous diploid strain of Aspergillus nidulans was utilized. Fluoxetine at 7.5, 15, and 30 microM concentrations induced homozygosity of several nutritional genetic markers and significantly increased their homozygotization index values. Since mitotic recombination is a mechanism leading to malignant growth through the loss of a functional copy of a heterozygous tumor-suppressor gene, fluoxetine may be characterized as an inducer of secondary malignancies in cancer patients after antidepressant treatment.
Asunto(s)
Antidepresivos de Segunda Generación/farmacología , Aspergillus nidulans/efectos de los fármacos , Fluoxetina/farmacología , Pérdida de Heterocigocidad/efectos de los fármacos , Mutación/efectos de los fármacos , Recombinación Genética/efectos de los fármacos , Antidepresivos de Segunda Generación/efectos adversos , Aspergillus nidulans/genética , Intercambio Genético , Diploidia , Relación Dosis-Respuesta a Droga , Fluoxetina/efectos adversos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Heterocigoto , Humanos , Pérdida de Heterocigocidad/genética , Pruebas de Sensibilidad Microbiana , Mutación/fisiologíaRESUMEN
O objetivo do estudo foi avaliar o desempenho da reação em cadeia da polimerase (PCR) para detectar o DNA de Trypanosoma cruzi no sangue de camundongos infectados com clones do protozoário pertencentes aos genótipos 19, 20 (T. cruzi I), 39 e 32 (T. cruzi II), comparando-o com o exame de sangue a fresco (ESF), a hemocultura (HC) e o teste imunoenzimático (ELISA). Foram analisadasamostras de sangue de camundongos BALB/c experimentalmente infectados com 20 clones. A positividade da PCR foi significativamente superior à das demais técnicas estudadas e a seguinte ordem de positividade foi observada: PCR (100,00) > ELISA(94,44) > HC (78,86) > ESF (73,28). Ao contrário da ELISA, HC e ESF, a positividade da PCR não variou de acordo com o genótipo. Esses dados mostram o potencial da técnica da PCR para o diagnóstico da doença de Chagas.