RESUMEN
OBJECTIVE: To investigate the expression of microRNA-183 (miR-183) and Ezrin protein in stage II( gastric cancer (GC). METHODS: Specimens of stage II( GC and paracancer tissues (5 cm away from the tumor tissues) were collected from 72 patients. Real-time PCR was used to detect the miR-183 expression. Immunohistochemistry was used to examine the Ezrin protein expression in the tumor tissue. The associations of miR-183 expression with the clinicopathologic features of stage II( GC and Ezrin expression were analyzed. RESULTS: miR-183 expression was lower in stage II( gastric cancer tissues compared with the paracancer tissues samples(median relative expression, 0.676 vs. 1.000, P<0.05). Low expression of miR-183 was significantly associated with histological differentiation(0.429 vs. 0.907, P<0.05), lymph node metastasis(0.507 vs. 0.908, P<0.05). The survival was shorter in patient with low expression of miR-183(63.0±4.0) as compared to those with high expression of miR-183(75.2±3.8)(P<0.05). There was a negative correlation between the expression of miR-183 and Ezrin(r=-0.272, P<0.05). CONCLUSIONS: miR-183 is down-regulated in stage II( GC, and associated with the differentiation, metastasis, and prognosis. Ezrin is a potential regulatory protein of miR-183.
Asunto(s)
Proteínas del Citoesqueleto/metabolismo , MicroARNs/genética , Neoplasias Gástricas/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologíaRESUMEN
BACKGROUND: An ancient cyanobacterial incorporation into a eukaryotic organism led to the evolution of plastids (chloroplasts) and subsequently to the origin of the plant kingdom. The underlying mechanism and the identities of the partners in this monophyletic event remain elusive. METHODOLOGY/PRINCIPAL FINDINGS: To shed light on this evolutionary process, we sequenced the genome of a cyanobacterium residing extracellularly in an endosymbiosis with a plant, the water-fern Azolla filiculoides Lam. This symbiosis was selected as it has characters which make it unique among extant cyanobacterial plant symbioses: the cyanobacterium lacks autonomous growth and is vertically transmitted between plant generations. Our results reveal features of evolutionary significance. The genome is in an eroding state, evidenced by a large proportion of pseudogenes (31.2%) and a high frequency of transposable elements (approximately 600) scattered throughout the genome. Pseudogenization is found in genes such as the replication initiator dnaA and DNA repair genes, considered essential to free-living cyanobacteria. For some functional categories of genes pseudogenes are more prevalent than functional genes. Loss of function is apparent even within the 'core' gene categories of bacteria, such as genes involved in glycolysis and nutrient uptake. In contrast, serving as a critical source of nitrogen for the host, genes related to metabolic processes such as cell differentiation and nitrogen-fixation are well preserved. CONCLUSIONS/SIGNIFICANCE: This is the first finding of genome degradation in a plant symbiont and phenotypically complex cyanobacterium and one of only a few extracellular endosymbionts described showing signs of reductive genome evolution. Our findings suggest an ongoing selective streamlining of this cyanobacterial genome which has resulted in an organism devoted to nitrogen fixation and devoid of autonomous growth. The cyanobacterial symbiont of Azolla can thus be considered at the initial phase of a transition from free-living organism to a nitrogen-fixing plant entity, a transition process which may mimic what drove the evolution of chloroplasts from a cyanobacterial ancestor.
Asunto(s)
Cianobacterias/crecimiento & desarrollo , Cianobacterias/genética , Helechos/microbiología , Genoma Bacteriano/genética , Simbiosis/fisiología , Evolución Biológica , Fijación del Nitrógeno/genética , Fijación del Nitrógeno/fisiología , Simbiosis/genéticaRESUMEN
OBJECTIVE: To provide DNA molecular marker for identification of Nelumbo nucifera by exploring the differences of nrDNA-ITS sequence of N. nucifera originated from different habitats. METHOD: To compare nrDNA-ITS base sequence using specific PCR-ITS. RESULT: The completed sequence of ITS and 5.8 S rDNA, and the partial sequences of 18S rDNA and 26S rDNA, totally 750 bp, from N. nucifera were obtained. The differences among N. nucifera from different habitats and from different cultivars were found. CONCLUSION: The method can be used to identify N. nucifera among different species and to distinguish their fakes. It provided the basis for identifying N. nucifera from different geographical regions by comparison of their ITS sequences.
Asunto(s)
ADN de Plantas/genética , ADN Espaciador Ribosómico/genética , Nelumbo/genética , Plantas Medicinales/genética , Secuencia de Bases , China , ADN de Plantas/química , ADN de Plantas/metabolismo , ADN Espaciador Ribosómico/clasificación , Desoxirribonucleasa EcoRI/metabolismo , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Contaminación de Medicamentos/prevención & control , Geografía , Nelumbo/clasificación , Filogenia , Plantas Medicinales/clasificación , Reacción en Cadena de la Polimerasa , ARN Ribosómico/genética , ARN Ribosómico 18S/genética , ARN Ribosómico 5.8S/genética , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Symbiotic Anabeana azollae and its host plant Anabeana-free Azolla were isolated from 16 Azolla accessions representing different Azolla species or geographic origins.DNA polymorphic fragments were obtained by simultaneous RAPD amplification of both symbiont and host. The UPGMA clusters of Anabeana azollae and its host Azolla were established separately based on Dice coefficient caculation and a coordinated relationship was shown between Anabeana azollae and its Azolla host along both individual genetic divergence,but this genetic homology was reduced among different strains within Azolla species while the obvious mutants of Anabeana azollae were detected in some Azolla tested strains collected from different geographic area in the same host species.