Cotton genome mapping with new microsatellites from Acala ‘Maxxa’ BAC-ends

Fine mapping and positional cloning will eventually improve with the anchoring of additional markers derived from genomic clones such as BACs. From 2,603 new BAC-end genomic sequences from Gossypium hirsutum Acala ‘Maxxa’, 1,316 PCR primer pairs (designated as MUSB) were designed to flank microsatellite or simple sequence repeat motif sequences. Most (1164 or 88%) MUSB primer pairs successfully amplified DNA from three species of cotton with an average of three amplicons per marker and 365 markers (21%) were polymorphic between G. hirsutum and G. barbadense. An interspecific RIL population developed from the above two entries was used to map 433 marker loci and 46 linkage groups with a genetic distance of 2,126.3 cM covering approximately 45% of the cotton genome and an average distance between two loci of 4.9 cM. Based on genome-specific chromosomes identified in G. hirsutum tetraploid (A and D), 56.9% of the coverage was located on the A subgenome while 39.7% was assigned to the D subgenome in the genetic map, suggesting that the A subgenome may be more polymorphic and recombinationally active than originally thought. The linkage groups were assigned to 23 of the 26 chromosomes. This is the first genetic map in which the linkage groups A01 and A02/D03 have been assigned to specific chromosomes. In addition the MUSB-derived markers from BAC-end sequences markers allows fine genetic and QTL mapping of important traits and for the first time provides reconciliation of the genetic and physical maps. Limited QTL analyses suggested that loci on chromosomes 2, 3, 12, 15 and 18 may affect variation in fiber quality traits. The original BAC clones containing the newly mapped MUSB that tag the QTLs provide critical DNA regions for the discovery of gene sequences involved in biological processes such as fiber development and pest resistance in cotton. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Evaluation of the 23S rRNA gene as target for qPCR based quantification of Frankia in soils

The 23S rRNA gene was evaluated as target for the development of Sybr Green-based quantitative PCR (qPCR) for the analysis of nitrogen-fixing members of the genus Frankia or subgroups of these in soil. A qPCR with a primer combination targeting all nitrogen-fixing frankiae (clusters 1, 2 and 3) resulted in numbers similar to those obtained with a previously developed qPCR using nifH gene sequences, both with respect to introduced and indigenous Frankia populations. Primer combinations more specifically targeting three subgroups of the Alnus host infection group (cluster 1) or members of the Elaeagnus host infection group (cluster 3) were specific for introduced strains of the target group, with numbers corresponding to those obtained by quantification of nitrogen-fixing frankiae with both the 23S rRNA and nifH genes as target. Method verification on indigenous Frankia populations in soils, i.e. in depth profiles from four sites at an Alnus glutinosa stand, revealed declining numbers in the depth profiles, with similar abundance of all nitrogen-fixing frankiae independent of 23S rRNA or nifH gene targets, and corresponding numbers of one group of frankiae of the Alnus host infection only, with no detections of frankiae representing the Elaeagnus, Casuarina, or a second subgroup of the Alnus host infection groups.     

放牧对短花针茅荒漠草原建群种与优势种空间分布关系的影响

采用多种分析方法探讨放牧对短花针茅荒漠草原建群种与优势种无芒隐子草、碱韭的种群空间分布关系的影响.结果表明: 短花针茅+无芒隐子草+碱韭群落的景观特征主要由草原的土壤理化性质和种群的固有属性决定.自由放牧导致的空间分布的变异程度为碱韭>无芒隐子草>短花针茅.自由放牧对短花针茅和碱韭密度的影响显著,但对无芒隐子草影响不大.随着无芒隐子草密度的增加,自由放牧区短花针茅密度呈现增大趋势,而围封区短花针茅种群密度呈现先增大后减小的趋势;自由放牧区和围封区内短花针茅密度均随碱韭密度的增加而减小.表明植物种群种间关系存在密度效应,在受到外界干扰的情况下,密度效应可能消失;因植物种对或干扰条件不同,植物种间关系可以有多种表现形式.     

社会工作理念与医患冲突调解机制的建立

社会工作作为一种综合性专业性的助人活动,其理念应用于医疗实践能以专业的价值观和科学的方法,通过提供各种辅导和服务,协助患者及其家属与医方进行有效的沟通,促使医疗技术和服务更人性化地满足患者的需要,从而构建和谐的医患关系。在此过程中,社会工作者针对医患关系发展的不同阶段,分别拓展出不同的工作策略,扮演不同的服务角色。     

构建医患和谐：大型医院图书馆的医学信息服务的“三个面向”

针对临床医疗引发的医患矛盾,从医学信息服务角度提出了以面向医院管理层、临床医务人员和患者的医学信息服务来化解矛盾,阐述了大型医院图书馆以医学信息服务为纽带,构建医患和谐的工作要点。     

A Comprehensive Proteomic Analysis of the Type III Secretome of Citrobacter rodentium

Enteropathogenic Escherichia coli, enterohemorrhagic E. coli, and Citrobacter rodentium belong to the family of attaching and effacing (A/E) bacterial pathogens. They intimately attach to host intestinal epithelial cells, trigger the effacement of intestinal microvilli, and cause diarrheal disease. Central to their pathogenesis is a type III secretion system (T3SS) encoded by a pathogenicity island called the locus of enterocyte effacement (LEE). The T3SS is used to inject both LEE- and non-LEE-encoded effector proteins into the host cell, where these effectors modulate host signaling pathways and immune responses. Identifying the effectors and elucidating their functions are central to understanding the molecular pathogenesis of these pathogens. Here we analyzed the type III secretome of C. rodentium using the highly sensitive and quantitative SILAC (stable isotope labeling with amino acids in cell culture)-based mass spectrometry. This approach not only confirmed nearly all known secreted proteins and effectors previously identified by conventional biochemical and proteomic techniques, but also identified several new secreted proteins. The T3SS-dependent secretion of these new proteins was validated, and five of them were translocated into cultured cells, representing new or additional effectors. Deletion mutants for genes encoding these effectors were generated in C. rodentium and tested in a murine infection model. This study comprehensively characterizes the type III secretome of C. rodentium, expands the repertoire of type III secreted proteins and effectors for the A/E pathogens, and demonstrates the simplicity and sensitivity of using SILAC-based quantitative proteomics as a tool for identifying substrates for protein secretion systems.     

蚂蚁光顾云南紫胶虫对其天敌紫胶黑虫种群的影响

为了弄清蚂蚁光顾云南紫胶虫Kerria yunnanensis Ouet Hong对其天敌紫胶黑虫Holcocera pulverea Meyr种群的影响,于云南紫胶虫成虫期,对有无蚂蚁光顾的胶被抽样,调查胶被上紫胶黑虫的为害率及种群数量变化。结果显示,紫胶黑虫对有无蚂蚁光顾的胶被的为害率均很高,并逐月增加;其中有蚂蚁光顾的胶被紫胶黑虫的为害率略小于无蚂蚁光顾的胶被。蚂蚁光顾能明显减少紫胶黑虫的种群数量(︱t︱=2.764,df=356,P<0.01),其原因可能是蚂蚁光顾能干扰紫胶黑虫的产卵行为、破坏卵、取食卵和幼虫并且这种保护主要发生在云南紫胶虫幼虫期;云南紫胶虫进入成虫期后,由于紫胶黑虫生活于胶被内,并且产卵于胶被的凹陷处或雄虫胶壳内或雌虫肛突孔处,蚂蚁很少与紫胶黑虫相遇,故蚂蚁光顾对紫胶黑虫每月增长量没有显著影响(︱t︱=0.970,df=161,P>0.05)。紫胶黑虫和蚂蚁相遇的行为反应存在显著差异(χ2=4.781,df=1,P<0.05),蚂蚁对紫胶黑虫有捕食作用。蚂蚁与云南紫胶虫之间存在互利关系。蚂蚁取食云南紫胶虫的蜜露,能降低紫胶黑虫的为害率,并减少紫胶黑虫的种群数量,从而保护云南紫胶虫。     

桂林漓江沿岸植物区系特点及其与景观的关系

桂林漓江沿岸原生植被受破坏严重 ,植物区系为次生性质 ,其特点 :( 1 )种类丰富 ,共有野生维管束植物 80 8种 ,隶属于 1 5 6科、483属 ;( 2 )植物区系的地理成份复杂 ,可将 45 4个种子植物属归为 1 4个类型 ,以热带、亚热带类型为主 ,温带类型次之 ,中国特有属 6个 ;( 3 )植物区系岩溶特性明显 ,属于东亚植物区、中国—日本森林植物亚区、岭南山地地区的一个小区。植物景观是桂林漓江沿岸风景的重要组成部分 ,具体表现在各类植物群落的外貌和一些重要植物种类的花、果和叶色的季节性变化上。现存的主要植物群落以次生藤刺灌丛为主 ;少见尚存的喀斯特常绿、落叶阔叶混交林 ;独有的喀斯特硬叶常绿阔叶林 :以乌冈栎为建群种的山顶矮林 ,是我国东部湿润亚热带地区罕见的残遗植被类型 ,在构成景观和科研上均有特殊意义。沿河岸分布的植物是最吸引游人注意的重要景观 ,形状各异的灌丛、杂木林、竹林和农田植被等都是风景的重要组成部分     

Habitat influences on urban avian assemblages

Urbanization is increasing across the globe and there is growing interest in urban ecology and a recognition that developed areas may be important for conservation. We review the factors influencing urban avian assemblages, focusing on habitat type and anthropogenic resource provision, and analyse data from a common bird monitoring scheme to assess some of these issues. The review suggests that (1) local factors are more important than regional ones in determining the species richness of urban avian assemblages, raising the potential for the management of urban sites to deliver conservation; (2) habitat fragmentation frequently influences urban avian assemblages, with the effects of patch size being greater than those of isolation, and (3) urban bird assemblages appear to respond positively to increasing the structural complexity, species richness of woody vegetation and supplementary feeding, and negatively to human disturbance. Data from Britain's Breeding Bird Survey, combined with habitat data obtained from aerial photographs, were used to assess a number of these issues at the resolution of 1‐km squares. Green‐space constituted 45% of these squares, and domestic gardens contributed 50% of this green‐space, though their contribution to large continuous patches of green‐space was negligible. There was no significant positive correlation between the densities of individual species in urban areas and surrounding rural areas. Rural species richness declined with increasing latitude, but urban species richness was not correlated with latitude. This contrast contributes to slightly higher avian species richness in rural squares in Southern England than urban ones. Occupancy and abundance were strongly positively correlated in urban avian assemblages, and some indicator species of conservation concern occurred in few urban areas and at low densities. Such species will require conservation action to be precisely targeted within urban areas. Of the urban indicators of conservation concern, only the House Sparrow Passer domesticus and Common Starling Sturnus vulgaris were more abundant in urban than rural areas. Moreover, the densities of these two species were strongly and positively correlated, indicating that they may be limited by shared resources, such as nest‐sites or supplementary food. There was little evidence that high densities of nest‐predating corvids were associated with reduced densities of their prey species. Species richness and the densities of individual species frequently declined with an increasing number of buildings. Current trends for the densification of many British urban areas are thus likely to be detrimental for many bird species.     

On the general dynamic model of oceanic island biogeography

Aim To investigate the biological meaning of equations used to apply the general dynamic model (GDM) of oceanic island biogeography proposed by R. J. Whittaker, K. A. Triantis and R. J. Ladle. Location Analyses are presented for 17 animal groups living on the Aeolian Islands, a volcanic archipelago in the central Mediterranean, near Sicily. Methods In addition to the mathematical implementation of the GDM proposed by Whittaker, Triantis and Ladle, and termed here logATT² (, where S is species number or any other diversity metric, t is island age, A is island area, and a, b, c and d are fitted parameters), a new implementation based on the Arrhenius equation of the species–area relationship (SAR) is investigated. The new model (termed powerATT²) is: . For logATT² and powerATT² models, equations were developed to calculate (1) the expected number of species at equilibrium (i.e. when the island has reached maturity) per unit area (S_eq), and (2) the time required to obtain this value (t_eq). Whereas the intercept in the Gleason model (S = C + z log A) or the coefficient of the Arrhenius power model (S = CA^z) of the SAR can be considered measures of the expected number of species per unit area, this is not the case for the parameter a of the ATT² models. However, values of S_eq can be used for this purpose. The index of ‘colonization ability’ (CAB), calculated as the ratio , may provide a measure of the mean number of species added per unit area per unit time. Results Both ATT² models fitted most of the data well, but the powerATT² model was in most cases superior. Equilibrial values of species richness (S_eq) varied from c. 3 species km^?2 (reptiles) to 100 species km^?2 (mites). The fitted curves for the powerATT² model showed large variations in d, from 0.03 to 3. However, most groups had values of d around 0.2–0.4, as commonly observed for the z‐values of SARs modelled by a power function. Equilibration times ranged from about 170,000 years to 400,000 years. Mites and springtails had very high values of CAB, thus adding many more species per unit area per unit time than others. Reptiles and phytophagous scarabs showed very low values, being the groups that added fewest species per unit area per unit time. Main conclusions Values of equilibrial species richness per unit area are influenced by species biology (e.g. body size and ecological specialization). Theoretical and empirical evidence suggests that higher immigration rates should increase the z‐values of the Arrhenius model. Thus, in the same archipelago, groups with larger z‐values should be characterized by higher dispersal ability. Results obtained here for the parameter d conform to this prediction.