ABSTRACT
Promoters play critical roles in controlling the transcription of genes and are important as tools to drive heterologous expression for biotechnological applications. In addition to core transcription factor-binding motifs that assist in the binding of RNA polymerases, there are specific nucleotide sequences in a promoter region to allow regulation of gene expression. The allene oxide synthase (AOS) gene family are cytochrome P450s that are responsive to a variety of environmental stress, making them good candidates for the discovery of inducible promoters. Populus AOS homologs separate phylogenetically into two clades. Based on the 19 promoter motifs with significant abundance differences between the two clades, Clade I AOS genes are likely more responsive to hormones, salt, and pathogen, whereas clade II homologs are likely inducible by water stress. In this study, an upstream promoter from a Clade I poplar AOS encoding gene (AOS1) was cloned and used to drive the expression of a ß-glucuronidase (GUS) gene in Arabidopsis. AOS is an essential enzyme in the lipoxygenase pathway that is responsible for the production of many non-volatile oxylipins in plants, including the jasmonates, which are regulatory phytohormones coordinating a variety of biological and stress response functions. Consistent with AOS transcript expression patterns, we found that the poplar AOS1 promoter drives rapid and localized expression by wounding. The study provides insight on the responsive elements in the poplar AOS promoters, but more importantly identifies a strong wound-inducible and localized promoter for future applications.
ABSTRACT
Gráficos com demonstração das curvas ângulo-tempo das articulações dos membros dos eqüinos foram avaliados por meio da análise de imagens digitalizadas tomadas de 10 cavalos e 13 éguas da raça Mangalarga Marchador. Foram utilizados marcadores reflexivos adesivos colocados em 19 pontos articulares dos eqüinos, procedendo-se à filmagem com freqüência de 250 quadros por segundo e utilizando-se o aplicativo Simi-motion 3D 6.0 para digitalização e análise das imagens. A utilização dos marcadores reflexivos adesivos constituiu boa metodologia para análise dos movimentos dos segmentos ósseos dos eqüinos. Os resultados observados indicam haver, durante a locomoção dos eqüinos marchadores brasileiros, comportamento similar das articulações quando comparados com eqüinos de sela europeus, apresentando mesmo padrão das curvas de ângulo-tempo e não havendo grandes diferenças entre os pontos máximos de flexão e extensão.
Images of 10 horses and 13 mares of Mangalarga Marchador breed were taken and digitalized to analyze the joint angle-time curves. Reflexives and adhesives markers were glued on 19 articulations points of the hindlimbs and forelimbs of the horses. The images were taken at 250 frames per second and the digitalization and analysis were made using a Simi-motion 3D 6.0 software. The results demonstrated that the methodology using reflexives and adhesives markers was efficient to make analyses of the bone segment movements of the horses. This study concluded that the Brazilian gaited horses have a similar angle-joint curve as the European warmblood horses and there are no great differences of the maximum extension and flexion points.