Structural feature of sorghum chloroplast psbA gene and regulation effects of its 5'-noncoding region*

Comparative analysis reveals remarkable homology between the sequences of both psbA gene nucleotides and the inferred amino acids of sorghum, a C_4 plant, and those of rice, a C_3 plant. The 5'-noncoding region of sorghum psbA gene contains the conservative promoter elements, "-35" element and "-10" element, like the prokaryote and the promoter element, TATA box, like the eukaryote. As compared with that of the rice, an extra sequence of 7 bp is found in the leader sequence of the mRNA in the former. Using an in vitro system, it has been demonstrated that protein factor exists in sorghum chloroplast protein extract which specifically binds to the 5'-noncoding region of psbA gene. Measurement of the expression of luciferase shows a 2—5 time greater reaction of the expression plasmids pALqs which contain leader region of sorghum psbA gene than that of the expression plasmids pALqr which contain leader region of rice psbA gene in E. coli.     

白蜡虫若虫口器超微结构特征与生态适应性

超微结构表明,白蜡虫雌、雄若虫口器结构相同,均由外部的口针、下唇和唇基板,以及内部的口针囊和幕骨组成,且具有以下显著特点:(1)口器具口针囊,幕骨发达;(2)上唇退化,下唇短小、不分节;(3)下颚针具T型锁紧密相扣;(4)口器刚毛稀疏,感器单一.其中,口器上、下唇退化,幕骨发达,口针束伸缩可能主要受幕骨和口针囊控制,而口器感器退化则可能与其取食行为的高度特化有关.白蜡虫雌、雄虫口针长度和直径差异不显著(P＞0.05),而1龄、2龄若虫口针长度和直径差异显著(P＜0.05).1龄若虫由于口针较短,口针束较柔软,适宜穿刺较薄的叶片,故生活在叶片上,而2龄若虫由于口针较长,口针束较为坚硬,适宜穿刺比叶片厚的树皮,故返回枝条生活,且若虫从叶片转移到枝条上生活,可能是基于寻求安全栖息地和稳定食物来源.     

Distraction osteogenesis in correction of micrognathia accompanying obstructive sleep apnea syndrome

To evaluate the effect of distraction osteogenesis in correction of micrognathia accompanying obstructive sleep apnea syndrome, a total of 28 patients with different severities of obstructive sleep apnea syndrome underwent mandibular distraction osteogenesis. A total of 51 distraction devices were placed for bilateral distraction in 23 patients and for unilateral distraction in five patients. The mean age of patients was 21.2 years (range, 3 to 60 years). Eleven patients had micrognathia accompanying obstructive sleep apnea syndrome secondary to bilateral temporomandibular joint ankylosis, and 10 patients had micrognathia accompanying obstructive sleep apnea syndrome secondary to unilateral temporomandibular joint ankylosis. Three patients had developmental micrognathia accompanying obstructive sleep apnea syndrome. The other four patients had micrognathia and concomitant obstructive sleep apnea syndrome induced by trauma, infection, or tumor resection. Each patient had been evaluated preoperatively and postoperatively with cephalometry and polysomnography. Mandible advancement ranged from 9 to 30 mm (average, 20.4 mm) and was successfully achieved after distraction. Fine new bone formed in the distraction gap when the distraction devices were removed 3 to 4 months after distraction was completed. No infection or other complications occurred in any patients. Complete curative effects were achieved in nine severe, six moderate, and eight mild obstructive sleep apnea syndrome patients after distraction, and the other five patients had been improved to the mild level. After distraction was completed, the posterior airway space was increased on average from 4.6 mm to 12.5 mm and the sella-nasion-point B angle was increased on average from 66 degrees to 75 degrees on cephalometric studies. The polysomnographic examination showed that the apnea hypopnea index was lowered on average from 58.0 to 3.15, and the lowest oxygen saturation was increased on average from 77 percent to 90.3 percent after distraction was completed. The follow-up period was 3 to 61 months (average, 18.1 months). The curative effect was stable and no relapse occurred. Therefore, the authors conclude that mandibular distraction osteogenesis is an effective method for correcting micrognathia accompanying obstructive sleep apnea syndrome. Compared with other current routine surgical procedures, it has many advantages, such as low risk, simple manipulation, high curative rate, low relapse rate, and stable result. It is presently the most effective method for the treatment of this difficult and complicated disorder.     

人canstatin基因的克隆

为深化研究血管生成抑制剂canstatin的生物学性能和用于肿瘤生物治疗的可能性,针对canstatin cDNA序列设计引物,运用逆转录聚合酶链反应（RT－PCR）从人胚肝组织中钓取canstatin cDNA,将其克隆入pMND18-T载体中,通过酶切鉴定出重组体并测序分析,结果表明,获得684bp人canstatin基因,成功构建人canstatin cDNA 克隆载体pMB18-T/canstatin,为进一步进行canstatin蛋白表达及活性研究奠定了基础。     

抗噬菌体工程菌的筛选

噬菌体污染常引起溶菌,造成人力物力浪费。应用自发突变的原理成功地从溶菌液中筛选到抗噬菌体的工程菌株;在发酵罐中培养,该菌株生长行为和表达水平没有变化。     

油棕（Elaeis guineensis）中果皮发育过程中miRNA的表达动态分析

以CTAB法提取油棕（Elaeis guineensis）中果皮5个不同发育时期（G1～G5）的小RNA。从前期研究获得的油棕小RNA测序数据库中筛选12个候选miRNA,实时荧光定量PCR法（qRT-PCR）检测其在果实发育过程中的表达量变化,并进一步对显著差异表达的miRNA进行靶基因预测。结果表明：中果皮5个不同发育时期小RNA的OD260/OD280比值在1.7～2.0之间;浓度分别是289、364、476、213、390 ng/μL;qRT-PCR检测结果显示,12个候选miRNA在5个发育时期均显著性差异表达,特别是在中果皮发育第4个时期（G4）和第5个时期（G5）表达量极显著增高,其中miR395和miR156在第4个时期表达量最高;miR395和miR528在发育第5时期表达量最高;靶基因预测结果显示差异表达的部分miRNA,其靶基因可能参与了脂肪酸代谢通路,如磷脂酸磷酸脂酶和磷脂酶D。本研究筛选的与脂肪酸代谢相关的miRNA为今后油棕脂肪酸代谢调控通路研究提供了可能的线索。     

基于层次分析法的江苏宁镇山脉乡土树种评价

为了筛选适宜南京地区的优良城市绿化树种,在野外调查和问卷调查的基础上,利用层次分析法(AHP)建立江苏宁镇山脉乡土树种评价体系,对该区域的乡土树种进行客观的定量分析。结果表明:(1)乡土树种作为城市绿化树种应首先考虑抗逆性,其次是生态价值、美学价值和生物学特性;(2)参与评价的41种宁镇山脉乡土树种可分为4类,其中I类乡土树种应大力推广应用,Ⅱ类乡土树种可作为森林城市树种多样性的有益补充,Ⅲ类和Ⅳ类乡土树种作为城市绿化树种仍有一定的差距。13种Ⅰ类乡土树种作为城市绿化树种具有良好的应用前景。     

玉米O2/o2近等基因系胚乳中基因表达差异分析

对玉米Hz85(O2/O2)和 Hz85(o2/o2)以及S7913(O2/O2)和 S7913 (o2/o2)两种不同核背景下的近等基因系(NIL),采用cDNA芯片杂交技术研究玉米o2突变基因及赖氨酸形成和胚乳发生相关基因在RNA水平上的表达差异。在两套NILs中检测到共同的表达差异克隆87个,对其序列分析得到26个TUGs（tentative unique genes）、11个未命名蛋白和6个新序列。这些TUGs分别参与了生长发育、胁迫响应、物质运输、信号转导、电子传递链、细胞防御、代谢等细胞过程,以及作为细胞组分和贮存蛋白。基于O2/o2 NILs间胚乳发育中基因表达的差异,讨论了o2籽粒中的不透明粉质胚乳形成的分子机制。