RESUMO
The methanolic extract of the stem bark of Lafoensia pacari (Lythraceae) showed free radical scavenging activity in the diphenyl picryl hydrazyl radical (DPPH) decoloration assay and inhibited the enzyme xanthine oxidase 'in vitro'. Bioassay-guided isolation led to ellagic acid (EA) as the main active compound of Brazilian and Paraguayan collections of the plant.
Assuntos
Sequestradores de Radicais Livres/farmacologia , Plantas Medicinais/química , Álcoois , Brasil , Cromatografia Líquida de Alta Pressão , Sequestradores de Radicais Livres/isolamento & purificação , Radicais Livres/química , Epiderme Vegetal/química , Extratos Vegetais/farmacologia , Caules de Planta/química , Espectrofotometria Ultravioleta , Água , Xantina Oxidase/metabolismoRESUMO
An homologous transformation system has been developed for the plant pathogenic fungus Glomerella cingulata (Colletotrichum gloeosporioides). A transformation vector containing the G. cingulata gpdA promoter fused to the hygromycin phosphotransferase gene was constructed. Southern analyses indicated that this vector integrated at single sites in most transformants. A novel method of PCR amplification across the recombination junction point indicated that the integration event occurred by homologous recombination in more than 95% of the transformants. Deletion studies demonstrated that 505 bp (the minimum length of homologous promoter DNA analysed which was still capable of promoter function) was sufficient to target integration events. Homologous integration of the vector resulted in duplication of the gdpA promoter region. When transformants were grown without selective pressure, a high incidence of vector excision by recombination between the duplicated regions was evident. The significance of these recombination characteristics is discussed with reference to the feasibility of performing gene disruption experiments.
Assuntos
DNA Fúngico/genética , DNA Recombinante/genética , Vetores Genéticos , Fungos Mitospóricos/genética , Plantas/microbiologia , Recombinação Genética , Transformação Genética , Sequência de Bases , Proteínas Fúngicas/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Dados de Sequência Molecular , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/genéticaRESUMO
The glyceraldehyde-3-phosphate dehydrogenase gene (gpdA) has been identified from a genomic DNA library prepared from the plant pathogenic fungus Glomerella cingulata. Nucleotide sequence data revealed that this gene codes for a putative 338-amino-acid protein encoded by two exons of 129 and 885 bp, separated by an intron 216 bp long. The 5' leader sequence is also spliced by an intron of 156 bp. A cDNA clone was prepared using the polymerase chain reaction, the sequence of which was used to confirm the presence of the intron in the coding sequence and the splicing of the 5' leader sequence. The transcriptional start point (tsp) was mapped at -253 nt from the site of the initiation of translation by primer extension and is adjacent to a 42-bp pyrimidine-rich region. The general structure of the 5' flanking region shows similarities to gpdA from Aspergillus nidulans. The putative protein product is 71-86% identical at the aa level to GPDs from Aspergillus nidulans, Cryphonectria parasitica, Curvularia lunata, Podospora anserina and Ustilago maydis.
Assuntos
Ascomicetos/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Sequência de Aminoácidos , Ascomicetos/enzimologia , Sequência de Bases , Clonagem Molecular , Códon , DNA Fúngico , Íntrons , Dados de Sequência Molecular , Plantas/microbiologia , Homologia de Sequência de AminoácidosRESUMO
The repeatability of ovine faecal oocyst counts was studied in Merino of Arles and Romanov sheep over short (4 days) or longer periods (1 month). The repeatabilities over short periods ranged from 0.27 to 0.67 for total oocyst output, from 0.06 to 0.54 for Eimeria ovinoidalis and from 0.29 to 0.52 for E. parva counts. E. ovinoidalis had lower and more irregular repeatabilities than E. parva. Their repeatabilities ranged, respectively from 0.18 (E. ovinoidalis) to 0.22 (E. parva) for longer periods. The genetic share in the determination of magnitude of oocyst counts seems similar to that recorded for trichostrongylid egg counts.
