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WRKY is a superfamily of plant-specific transcription factors, playing a critical regulatory role in multiple biological processes such as plant growth and development, metabolism, and responses to biotic and abiotic stresses. Although WRKY genes have been characterized in a variety of higher plants, little is known about them in eukaryotic algae, which are close to higher plants in evolution. To fully characterize algal WRKY family members, we carried out multiple sequence alignment, phylogenetic analysis, and conserved domain prediction to identify the WRKY genes in the genomes of 30 algal species. A total of 24 WRKY members were identified in Chlorophyta, whereas no WRKY member was detected in Rhodophyta, Glaucophyta, or Bacillariophyta. The 24 WRKY members were classified into Ⅰ, Ⅱa, Ⅱb and R groups, with a conserved heptapeptide domain WRKYGQ(E/A/H/N)K and a zinc finger motif C-X4-5-C-X22-23-H-X-H. Haematococcus pluvialis, a high producer of natural astaxanthin, contained two WRKY members (HaeWRKY-1 and HaeWRKY-2). Furthermore, the coding sequences of HaeWRKY-1 and HaeWRKY-2 genes were cloned and then inserted into prokaryotic expression vector. The recombinant vectors were induced to express in Escherichia coli BL21(DE3) cells and the fusion proteins were purified by Ni-NTA affinity chromatography. HaeWRKY-1 had significantly higher expression level than HaeWRKY-2 in H. pluvialis cultured under normal conditions. High light stress significantly up-regulated the expression of HaeWRKY-1 while down-regulated that of HaeWRKY-2. The promoters of HaeWRKY genes contained multiple cis-elements responsive to light, ethylene, ABA, and stresses. Particularly, the promoter of HaeWRKY-2 contained no W-box specific for WRKY binding. However, the W-box was detected in the promoters of HaeWRKY-1 and the key enzyme genes HaeBKT (β-carotene ketolase) and HaePSY (phytoene synthase) responsible for astaxanthin biosynthesis. Considering these findings and the research progress in the related fields, we hypothesized that the low expression of HaeWRKY-2 under high light stress may lead to the up-regulation of HaeWRKY-1 expression. HaeWRKY-1 may then up-regulate the expression of the key genes (HaeBKT, HaePSY, etc.) for astaxanthin biosynthesis, consequently promoting astaxanthin enrichment in algal cells. The findings provide new insights into further analysis of the regulatory mechanism of astaxanthin biosynthesis and high light stress response of H. pluvialis.
Assuntos
Eucariotos , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismoRESUMO
Objective To summarize the clinical experiences of coronary artery bypass grafting ( CABG) in the treatment of coronary artery disease. Methods CABG were performed on 395 consecutive cases from January 2002 to December 2012,including 299 male and 96 female with a mean age of 62. 3 years old. All the operation were performed under cardiopulmonary bypass (CPB ) with moderate hypothermi-a. Left ventricular aneurysm plasty operation were performed in 18 patients. Results The mean number of grafts was 3. 2,the mean CPB time was 88 min( 62~170 min) ,aortic cross-clamping time was 68 min( 25~102 min) ,mean ventilation time was 18 h( 12~72 h) . There were 8 deaths with a mortality of 2. 0%. Six patients died of multiple organ failure,1 patients died of ventricular fibrillation after operation,1 patients died of acute myocardial infarction. Postoperative follow up was carried out on 280 cases,follow-up time was from 8 months to 11 years. Five of them died of unknow causes. The heart function of the rest was significantly improved. 195 patients were free of angina. 85 pa-tients’ s symptom got better. Conclusion CABG performed under cardiopulmonary bypass ( CPB ) with moderate hypothermia is safe and effective for the treatment of coronary artery disease.
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Objective To investigate the metabolism change of intestinal flora due to chronic hypoxia in infants. Methods Ten infants with tetralogy of fallot were considered as the chronic hypoxia group,10 healthy infants were regarded as the control group. The urine concen-tration of hippurate in the morning with fasting was detected by 1 H nuclear magnetic resonance. Results The concentration of hippurate was decreased in hypoxia group compared with the control group,(47. 15 ± 32. 88) mg/L vs (346. 698 ± 13. 555) mg/L,with significant differ-ence,P=0. 002. Conclusion Chronic hypoxia alters metabolism of intestinal flora in infants.
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By analyzing the status of Cardiovascular Surgery advanced students,we discussed the characteristics and problems of clinical teaching for advanced students of Cardiovascular Surgery.Strategies of clinical teaching for advanced students of cardiovascular surgery are explored to improve the quality of clinical teaching.
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Obiective To investigate the influence of rapid atrial pacing(RAP)on the expression of ?1c subunit of L-type calcium channel,and the protective effect of verapamil.Methods 30 rabbits were randomly assigned into RAP group and verapamil pre-conditioned group.Each group was further divided into 5 subgroups(n=3 for each subgroup).Electrode was embedded in the right atrium through right external jugular vein.Pacing was performed for 6h,12h,24h and 48h in different subgroups.No pacing in the sham operation group.For verapamil pre-conditioned group,the drug was intravenously administered(0.2mg/kg)30 minutes before the initiation of rapid atrial pacing.Right atrium tissue was harvested for determination of mRNA and protein expression of L-type calcium channel subunits by reverse transcription polymerase chain reaction(RT-PCR)and Western blot.Results The mRNA level of ?1c subunit started to be reduced 6h after rapid atrial pacing(RAP)and continued to decline as pacing continued,and the expression of protein was parallel with mRNA.Otherwise,the mRNA level of ?1c subunit started to decrease 24h after RAP and continued to decline while pacing continued,and the expression of protein paralleled with that of mRNA in verapamil pre-conditioned group.Verapamil can attenuate the down-regulation of L-type calcium channel of the atrium induced by RAP only at 24h after RAP,but the effect was less intent.Conclusion mRNA and protein expression level of L-type calcium channel subunits decreased after RAP,The calcium channel blocker verapamil can attenuate the down-regulation of L-type calcium channel of atrium induced by RAP resulting in a decrease or postponement of calcium overload in atrial myocytes,thus exerting protective effects on atrial electrical remodeling,but such effects vanished after prolonged pacing.