神经再生过程中脊髓运动神经元β管蛋白基因表达的变化

损伤大鼠右侧坐骨神经后,SDS—PAGE电泳分析双侧腹角细胞中蛋白含量变化,发现损伤侧的管蛋白相对含量较对照侧增加了17％—121％。损伤后3—14d损伤侧腹角运动神经元中β管蛋白mRNA的原位杂交信号增强了27％—70％,β管蛋白mRNA的Northern杂交分析也显示基因表达的增强。     

Cloning, sequencing and analyzing of the heavy chain V region genes of human polyreactive antibodies

The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction(PCR) technique.We found that 2 and 3 mAbs utilized genes of the VHIV and VHⅢ families,respectively.The former 2 VH segments were in germline configuration.A common VH segment,with the best similarity of 90.1% to the published VHⅢ germline genes,was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs.This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHⅢ gene.All these polyreactive mAbs displayed a large NDN region(VH-D-JH junction).The entire H chain V regions of these polyreactive mAbs are unusually basic.The analysis of the charge properties of these mAbs as well as those of other poly-and mono-reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites(CDRs),may be an important structural feature involved in antibody polyreactivity.     

松干蚧种群变动和生物防治

松干蚧是松树主要害虫之一,其中以日本松干蚧(Matsucoccus matsumurae Kuwana)为害最严重。1973年南京地区松干蚧猖獗发生。我院校园连片的马尾松(Pinus massonianaLamb.)和千头赤松[Pinus densiflora f.umbraculifera(Mayr) Beissner]等也暴发了此虫,当时曾作为江苏省松干蚧防治会议的现场。但是,直到 1978年 3月,原来这些松干蚧大发生的松树,未发现有因松干蚧为害致死现象;相反,他们长势愈来愈旺,松干蚧数量也降低到稳定水平。整个群落趋于稳定。除我院以外,南京市晓庄林场,溧阳县东方红林场等也有此现象。尤其是后者,松干蚧分布面积千亩以上,部分地区种群密度很大,但是也没有     

生物信息学本科人才培养的调研与思考

近年来,生物信息学已经逐步发展成为现代生物学和医学等领域的关键技术方法,社会对生物信息学专业人才的需求不断扩大,生物信息学的本科教育也受到了越来越多的关注和重视。为了探索更加合理的人才培养模式、完善课程设置和教学计划,本文以中美两国开设生物信息学本科专业的高校为对象,分别选取一些代表高校并进行深入调研,对比分析课程设置和人才培养现状。结果显示,生物信息学的跨学科性质在各高校中均得到一定体现,培养学生具有多元化的知识结构已经成为生物信息学人才培养的一项共识。同时,根据调研的结果,也对国内生物信息学本科教育提出一些启发与建议。     

Photosynthesis affects following night leaf conductance in Vicia faba

Night-time stomatal opening in C₃ plants may result in significant water loss when no carbon gain is possible. The objective of this study was to determine if endogenous patterns of night-time stomatal opening, as reflected in leaf conductance, in Vicia faba are affected by photosynthetic conditions the previous day. Reducing photosynthesis with low light or low CO₂ resulted in reduced night-time stomatal opening the following night, irrespective of the effects on daytime stomatal conductance. Likewise, increasing photosynthesis with enriched CO₂ levels resulted in increased night-time stomatal opening the following night. Reduced night-time stomatal opening was not the result of an inability to regulate stomatal aperture as leaves with reduced night-time stomatal opening were capable of greater night-time opening when exposed to low CO₂. After acclimating plants to long or short days, it was found that night-time leaf conductance was greater in plants acclimated to short days, and associated with greater leaf starch and nitrate accumulation, both of which may affect night-time guard cell osmotic potential. Direct measurement of guard cell contents during endogenous night-time stomatal opening will help identify the mechanism of the effect of daytime photosynthesis on subsequent night-time stomatal regulation.     

Involvement of ERK1/2 pathway in TGF-beta1-induced VEGF secretion in normal human cytotrophoblast cells

Transforming growth factor-beta1 (TGF-beta1) plays a pivotal role in the angiogenesis during the development of placenta, but the intracellular signaling mechanism by which TGF-beta1 stimulates this process remains poorly understood. In this article, we demonstrated that exposure of normal human cytotrophoblast cells to TGF-beta1 stimulated the secretion of the VEGF gene encoding vascular endothelial growth factor, which is a key factor in angiogenesis. Meanwhile, treatment of normal human cytotrophoblast cells with TGF-beta1-induced expression of HIF-1a, the regulated subunit of hypoxia-inducible factor 1, a known transactivator of the VEGF gene. Our data indicated that TGF-beta1 induced extracellular signal- regulated kinase (ERK) 1/2 phosphorylation in normal human cytotrophoblast cells. Moreover, treating cells with PD98059, an inhibitor of ERK1/2 signaling, inhibited TGF-beta1 stimulation of VEGF secretion and HIF-1a protein expression. These data indicated that in normal human cytotrophoblast cells, TGF-beta1 induced HIF-1a-mediated VEGF secretion, and TGF-beta1-stimulated-ERK1/2 activation may be involved in this process.     

CAAT结合蛋白CBF在转录中的作用

ＣＡＡＴ结构是一种在真核生物启动子中普遍存在的顺式作用元件。ＣＢＦ,又称为ＮＦ -Ｙ、ＣＰ１,是一个ＣＡＡＴ特异性转录因子。在转录过程中 ,ＣＢＦ与ＣＡＡＴ特异性结合 ,共同调控启动子的转录 ,本文综述了ＣＢＦ的结构及其在转录中的作用。１ＣＡＡＴ结构ＣＡＡＴ结构存在于由ＲＮＡ聚合酶Ⅱ所转录的大多数真核生物基因的近端启动子中〔１〕,它与其他的启动子元件相互协调 ,一起控制启动子的转录活性。在高等的真核细胞启动子中 ,ＣＡＡＴ一般位于 -８０区〔２〕。对不同物种的某些基因进行比较 ,发现ＣＡＡＴ结构在启动子上的位置以…     

Tube structure and original composition of Sinotubulites: shelly fossils from the late Neoproterozoic in southern Shaanxi, China

Abundant well-preserved shelly fossils of Sinotubulites occur in the upper part of the late Neoproterozoic Dengying Formation in Ningqiang County, Shaanxi Province, China. Unlike 'funnel-in-funnel' structures of co-occurring Cloudina shells, the tube of Sinotubulites is nearly cylindrical, composed of several thin layers and characterized by 'tube-in-tube' structure. The tube bears prominent longitudinal sculptures and/or irregular annulations, which were formed by the wrinkles of tube layers, and weaken gradually towards the inner layers. The irregular wrinkle ornament of the outer layer shows plastic feature of the Sinotubulites tubes, which may further imply that the organisms secrete the elastic and flexible organic-dominated walls with mineralization, possibly aragonitic. Detailed thin section and SEM studies indicate that the silicification occurred earlier than phosphatation. Specimens preserved in situ from Hubei and surface ornamentation and polygonal shape of the cross-section suggest that Sinotubulites probably lived as an epibenthos lying on the sea floor.     Aragonitic tube, Ediacaran, Shaanxi. China, Sinotubulites , tube structure.     

Between florivory and herbivory: inefficacy of decision‐making by generalist floriphilic katydids

1. Florivory, which is less studied but as equally widespread as herbivory, can have effects on plant and floral trait adaptations, individual fitness, and community interactions. However, there are still knowledge gaps in our understanding of florivory, including the role of neural constraints and diet specialisation of florivores in floral resource utilisation. 2. According to the neural constraint hypothesis, a generalist flower‐visiting katydid is expected to have lower decision‐making efficacy in feeding when subjected to the presence of both capitula and leaves, compared to the presence of either one of the two resources. 3. In the present study, experiments using the katydid, Phaneroptera brevis, and the plant, whiteweed, Ageratum conyzoides, were carried out to examine the foraging behaviour of the katydid to test our hypothesis. The results confirmed the prediction of the neural constraint hypothesis. 4. The decision‐making efficacy was generally lowered when the katydid was presented with the choice for both the resource that is preferred (capitula) and less preferred (leaves). It was also shown that Phaneroptera brevis is floriphilic, as it prefers capitula to leaves. 5. In conclusion, the first evidence of neural constraint in florivory is provided and suggests that more can be explored into the effects of neural constraints and diet specialisation in floral resource utilisation.