反转录转座子标记及在作物遗传育种中的应用

反转录转座子通过RNA中间体进行反转录而转座,广泛分布于各种植物基因组中,拷贝数多,异质性高,在种内和种间表现出较高的序列差异性和丰富的插入多态性。针对这些特点,开发出了几种基于反转录转座子的分子标记,如SSAP、RIVPI、RAP、REMAP和RBIP等。由于反转录转座子标记能揭示出丰富的多态性,因而在遗传多样性和系谱研究、遗传连锁图谱构建及性状基因定位等方面得到了应用。随着分离技术的不断改进,获取序列信息更加容易,反转录转座子作为分子标记用于作物遗传育种将具有广阔前景。     

A Ca2+-Dependent Protein Kinase Activity Associated with Serotonin Binding Protein

The endogenous phosphorylation of serotonin binding protein (SBP), a soluble protein found in central and peripheral serotonergic neurons, inhibits the binding of 5-hydroxytryptamine (5-HT, serotonin). A protein kinase activity that copurifies with SBP (SBP-kinase) was partially characterized and compared with calcium/calmodulin-dependent protein kinase II (CAM-PK II). SBP itself is not the enzyme since heating destroyed the protein kinase activity without affecting the capacity of the protein to bind [3H]5-HT. SBP-kinase and CAM-PK II kinase shared the following characteristics: (1) size of the subunits; (2) autophosphorylation in a Ca2+-dependent manner; and (3) affinity for Ca2+. In addition, both forms of protein kinase phosphorylated microtubule-associated proteins well and did not phosphorylate myosin, phosphorylase b, and casein. Phorbol esters or diacylglycerol had no effect on either of the protein kinases. However, substantial differences between SBP-kinase and CAM-PK II were observed: (1) CAM enhanced CAM-PK II activity, but had no effect on SBP-kinase; (2) synapsin I was an excellent substrate for CAM-PK II, but not for SBP-kinase; (3) 5-HT inhibited both the autophosphorylation of SBP-kinase and the phosphorylation of SBP, but had no effect on CAM-PK II. These data indicate that SBP-kinase is different from CAM-PK II. Phosphopeptide maps of SBP and SBP-kinase generated by digestion with S. aureus V8 protease are consistent with the conclusion that these proteins are distinct molecular entities. It is suggested that phosphorylation of SBP may regulate the transport of 5-HT within neurons.     

陆地表层系统动力学机制研究Ⅰ．──陆地表层系统和动力学方程

对陆地表层动力学的研究对象、研究内容及其基本理论方法作了阐述,以多学科综合的观点定义了陆地表层系统,包括时空尺度范围的约定、状态变量的选择、物质循环以及外界因子等的讨论;依据物质和能量守恒原理建立了陆地表层系统的非线性控制方程组,表述了各圈层之间物质循环和能量循环过程、反馈关系及其动力学联系;讨论了控制方程组的整体运作功能以及人类活动对陆地表层系统的影响．     

芜湖发电厂灰渣场植被状况

经实地考察发现,芜湖火力发电厂灰渣场自然定居的高等植物有30种,隶属于14个科29个属,主要包括菊科,禾本科和豆科,全部植物中,1,2年生草本植物18种,多年生草本植物9种,木本植物2种,影响植物分布的主要因素是灰渣的理化性质和灰渣场的自然改造程度。     

方程dx/dt=f(x(t-1))具有多个周期的周期解并蕴含浑沌的条件

本文给出了方程dx/dt=f(x(t-1))出现4/(2n 1),4/(2n-1),4/(2n-3),…,4/7,4/5,4/3,4一周期解并蕴含浑沌的一个条件。     

In vitro and clinical data analysis of Osteopontin as a prognostic indicator in colorectal cancer

Osteopontin (OPN) has been shown to promote colorectal cancer (CRC) progression; however, the mechanism of OPN‐induced CRC progression is largely unknown. In this study, we found that OPN overexpression led to enhanced anchorage‐independent growth, cell migration and invasion in KRAS gene mutant cells but to a lesser extent in KRAS wild‐type cells. OPN overexpression also induced PI3K signalling, expression of Snail and Matrix metallopeptidase 9 (MMP9), and suppressed the expression of E‐cadherin in KRAS mutant cells. In human CRC specimens, a high‐level expression of OPN significantly predicted poorer survival in CRC patients and OPN expression was positively correlated with MMP9 expression, and negatively correlated with E‐cadherin expression. Furthermore, we have found that 15 genes were co‐upregulated in OPN highly expression CRC and a list of candidate drugs that may have potential to reverse the secreted phosphoprotein 1 (SPP1) gene signature by connectivity mapping. In summary, OPN is a potential prognostic indicator and therapeutic target for colon cancer.     

Characterization and Mapping of Contaminated Sediments,Windermere Arm,Hamilton Harbour,Ontario, Canada

Windermere Arm is a 50-ha narrow channel located in the south-eastern portion of Hamilton Harbour, which is designated by the International Joint Commission (IJC) as one of the primary Areas of Concern in the Canadian waters of the Great Lakes. Sediments within the Arm have historically been contaminated with metals, PAHs, and to a lesser extent, PCBs. Sedimentological, geotechnical and geochemical investigations have been undertaken to determine the degree and the spatial extent of contamination. The thickness of contaminated sediment and their degree of contamination vary widely within the study site. Information on the thickness of contamination obtained from logging and chemical analysis of sediment cores agrees in general with the results of in situ penetrometer testing. Concentrations of Zn and Pb in some sub-samples are above the Severe Effect Level (SEL) for benthos set by the Ontario sediment quality guidelines. On average, surficial sediments tend to have lower metal concentrations than deeper sediments, probably due to the reduction of industrial point discharges. Apart from the two main boat slips, concentrations of PAHs are relatively low and in agreement with previously reported values. In contrast, new results yield higher values of PCB concentrations than previously reported, and 21 sub-samples of surficial sediment analyzed yielded values greater than 1 μg/g. Results suggest that the majority of recent PCB loadings are entering the study site from nearshore industrial spills or dumping, despite the detection of trace amounts of PCBs in a nearby creek. Pronounced sediment disturbance noted in several cores suggests that more contaminated historical sediments are at risk of being disturbed and re-exposed to the water column.     

卫星景象目视解释方法在湖区植被制图中的应用——以湖南洞庭湖区水域、洲滩植被图为例

植被(包括天然植被、人工植被)作为一种可更新资源始终是遥感应用专家们热心研究的课题。植被分类是植被研究的重要方面之一。利用卫星影象进行植被分类,国内外学者都进行了许多有意义的探索。本文以洞庭湖水域、洲滩植被为对象,试用卫星影象进行植被分类。本文从植被与环境相互依赖关系及在影象上的综合反映出发,提出了影象的景观生态学分析方法;即把影象上色调、形态特征与群落生态学规律结合起来分析,并以此作为植被目视解译的方法论。在此基础上,将洞庭湖水域,洲滩划分成五个景观生态模型,17个基本植被类型。     

Shoot regeneration after fire or freezing temperatures and its relation to plant life-form for some heathland species

Shoot regeneration after prescribed burning or following the freezing temperatures of winter was monitored for nineteen heathland species present in an Arctostaphyleto-Callunetum community in northeast Scotland. Species whose renewal buds were near the surface of the ground started to grow earlier in the spring than species with renewal buds above the surface, but grouping species according to the position of their renewal bud (i.e. their life-form) did not account for all of the interspecific variation apparent. In the case of shoot regeneration after fire, species whose renewal buds were destroyed by fire because they were above-ground started to regenerate about the same time as species with belowground buds, protected from fire, but reached their maximum frequency of occurrence later. Grouping species by life-form was of limited value as a means of interpreting this interspecific variation in the timing of shoot regeneration after fire. It would be unwise to use plant life-form as the sole basis for interpreting or predicting a species' response to temperature stress when extreme temperatures occur regularly, as they do in heathland. The possible use of other plant traits to interpret and predict interspecific variation in the regeneration rate of heathland plants is discussed.Nomenclature follows Tutin et al. (1964–1980) for vascular plants. Acknowledgements. The Nature Conservancy Council and Mr J. J. Humphries kindly allowed Dinnet Moor to be used for the work presented here. One of us (RJR) received financial support for field work from the Natural Sciences and Engineering Research Council of Canada.