横纹金蛛卵袋结构与纤维组成

采用SEM和氨基酸自动分析仪对横纹金蛛(Argiope bruennichi)卵袋的超微结构与氨基酸组成进行了观察研究.结果表明,横纹金蛛卵袋呈封闭的葫形,是由多种丝腺纺出的微米与纳米级的丝纤维形成的多个覆盖层构成,具有多层复杂结构,从外向内分别为:框架、卵袋覆盖帽、外覆盖层和内覆盖层、卵块覆盖帽、卵块包裹层,其中外覆...     

悦目金蛛卵袋的结构与组成

采用SEM和氨基酸自动分析仪对悦目金蛛(Argiope amoena)卵袋的结构、纤维组成和覆盖层的氨基酸组成进行了观察研究.结果表明悦目金蛛卵袋呈封闭的倒三角形,是由多种丝腺纺出的丝纤维形成的多个覆盖层构成的,从外向内分别为:金黄色大壶状腺框架丝,灰绿色、浅棕色、白色外覆盖层和棕色内覆盖层,其中外覆盖层是由6根大直径(约4.8-6.8 μm) 柱状腺丝纤维和一些小直径(约0.26-0.76 μm)纤维混合成的基本纤维束单元所折叠成的片层丝被构成的,小直径丝纤维的数量从灰绿色丝被(外)到白色丝被(内)逐渐增加,而内覆盖层仅仅是由6根大直径(约5.20 μm)柱状腺丝纤维构成的基本纤维束单元折叠而成.卵袋外覆盖层丝(白色绒状纤维除外)的甘氨酸、丙氨酸和丝氨酸等氨基酸的百分含量分别介于卵袋内覆盖层丝和葡萄状腺丝相对应氨基酸的百分含量之间,这一数据支持Foradori等关于卵袋小直径丝纤维是由葡萄状腺纺出的推论.悦目金蛛能调节卵袋层丝的颜色、直径、覆盖层丝纤维和氨基酸的组成,使卵袋获得各方面最优化的功能,为卵或若蛛提供支持和保护.     

棒络新妇卵袋结构与组成

采用SEM和氨基酸自动分析仪对棒络新妇 Nephila clavata 卵袋进行了结构观察和氨基酸组成分析.结果 表明棒络新妇的卵袋呈开放的网筛椭球状,结构简单,分为框架(大壶状腺丝)、金黄色或白色外层(主要含大壶状腺丝)和白色内层(主要含柱状腺丝)三部分,内外层都是由大(approx. 6～13 μm)、中(1.25～3.0 μm)、小(approx. 0.7～0.8 μm)直径的丝纤维构成.卵袋框丝和外层丝的氨基酸组成相似,甘氨酸(分别占22.9%和32.5%)和丙氨酸(占24%左右)的含量最丰富,其次是谷氨酸(占16.5%左右)和丝氨酸(分别占8.3%和3%),苏氨酸含量低(分别占2.12%和0.68%).与外层丝相比,卵袋内层丝纤维丝氨酸和苏氨酸的含量显著增加,分别为19.1%和6.11%左右,同时甘氨酸的含量显著减少,为7.2%左右,谷氨酸和脯氨酸的含量较低.大小侧链氨基酸比值(LC:SC)分析表明卵袋内层丝(1.03)﹥卵袋框丝(0.85)＞卵袋外层丝(0.66)≈拖牵丝(0.64)＞蚕丝(0.34),似乎表明卵袋框丝是不同于同纺自大壶状腺的典型蛛丝(拖牵丝)的新型蛛丝纤维.卵袋内层的主要构成成分是另一种具有截然不同氨基酸组成的柱状腺丝.棒络新妇能调节卵袋层丝的颜色、直径、丝纤维的组成及覆盖层的氨基酸组成,使卵袋获得各方面最优化的功能,为卵或若蛛提供支持和保护.     

3种中型蜘蛛卵袋形态特征与纤维组成结构

采用扫描电镜和氨基酸自动分析仪对球蛛科(Theridiidae)温室拟肥腹蛛(Parasteatodatepidariorum)、肖蛸蛛科(Tetragnathidae)肩斑银鳞蛛(Leucauge blanda)及狼蛛科(Lycosidae)猴马蛛(Hippasa holmerae)3种中型蜘蛛卵袋的超微结构和氨基酸组成进行了观察。形态观察表明,这3种蜘蛛的卵袋形态各异,温室拟肥腹蛛卵袋一头尖,呈梨状;肩斑银鳞蛛卵袋呈扁平状;猴马蛛卵袋呈椭球形。扫描电镜观察表明,温室拟肥腹蛛卵袋外覆盖层仅仅由一种均一直径的柱状腺丝组成,而另外2种蜘蛛卵袋外覆盖层主要由柱状腺丝与少量其他丝腺纺出的丝纤维组成。氨基酸组成分析表明,温室拟肥腹蛛卵袋外覆盖层的丝纤维的氨基酸组成与具有保守性的其他种类蜘蛛柱状腺丝心蛋白的氨基酸组成差异较大,这表明其可能含有新的丝心蛋白家族成员。本文根据氨基酸组成与扫描电镜的结果分析探讨了不同直径丝纤维的丝腺来源。     

摩鹿加云斑蛛卵袋结构与纤维组成

采用扫描电子显微镜（SEM）和氨基酸自动分析仪对摩鹿加云斑蛛Cyrtophora moluccensis卵袋的结构和组成进行了观察研究.结果表明摩鹿加云斑蛛的卵袋呈椭球状,是由多种丝腺纺出的微米与纳米级的丝纤维形成的多个覆盖层构成的,包括白色框架、军绿色与灰白色外覆盖层和白色内覆盖层3部分.卵袋框丝与典型的拖牵丝氨酸组成基本相似,丙氨酸和甘氨酸的含量最丰富,分别约占39%和33%,其次是谷氨酸、丝氨酸和脯氨酸,分别约占7.8%、5.7%和3.6%;其余卵袋丝纤维的氨基酸组成与典型的柱状腺丝相似,与卵袋框丝相比,卵袋覆盖层的丝氨基酸的含量显著增加,约占21%,同时甘氨酸和脯氨酸的含量显著减少,分别约占12%和1%,并含有更多的极性和大侧链氨基酸,其丙氨酸的含量变化不大,仍占了27%左右.根据氨基酸组成与扫描电镜的结果综合分析了不同自径丝纤维的丝腺来源.     

悦目金蛛和棒络新妇卵袋丝物理化学结构表征及其力学性能研究

蜘蛛丝是一种具有优良机械性能的天然动物蛋白纤维,它特有的结构和性能与其生物学功能密切相关。作者采用氨基酸自动分析仪、傅立叶转换红外光谱仪、扫描电镜和电子单纤强力仪对悦目金蛛（Argiope amoena）和棒络新妇（Nephila clavata）的卵袋丝进行了物理化学结构表征与力学性能的研究,结果表明两种蜘蛛卵袋均由微米级柱状腺丝、大壶状腺丝、亚微米级或纳米级葡萄状腺丝构成。卵袋丝的表面形貌特征、极性氨基酸含量、大侧链与小侧链氨基酸的比值、无定型区、β-折叠结构与结晶结构的含量等氨基酸组成种类与蛋白质二级结构特征,均满足各自生物学功能对断裂强度、延展性、初始模量等力学性能的要求。     

两种寄生蜂的卵巢结构与卵成熟特点初步观察

对斜纹夜蛾的内寄生蜂双斑侧沟茧蜂MicroplitisbicoloratusChen和南美斑潜蝇的外寄生蜂潜蝇姬小蜂Diglyhusisaea(Walker)的卵巢结构进行了研究。双斑侧沟茧蜂的2个卵巢管底部膨大有大量的卵,通过凹陷的颈部与萼区相连接,在萼区里大量成熟待产的卵浸泡在萼液中。产卵量随产卵时间延长而降低,在日产卵实验中,日产卵量202(±114SE),从1000至1800每2h的产卵量分别占日产卵量的38,32,17和13%;在一生产卵量实验中,9d产卵期,每头雌峰一生平均产卵量为502(±78SE)粒,第1d产卵量占一生总产卵量的42%。潜蝇姬小蜂的每个卵巢由3条卵巢管组成,每条输卵管中仅有1粒成熟卵,整个卵巢中只有6粒成熟卵,每次产卵数不超过6粒。结果表明,M.bicoloratus是早熟卵(proovigenic)类昆虫;D.isaea是同步卵(synovigenic)类昆虫。     

西双版纳热带季节雨林凋落叶分解与土壤动物群落：两种网孔分解袋的分解实验比较

 以西双版纳热带湿性季节沟谷雨林混合凋落叶作为分解基质,在不同位置季节雨林样地,采用不同网孔（ 2和0.15 mm）分解袋,开展大中型土壤动物对雨林凋落叶分解影响的实验,测定了不同网孔分解袋土壤动 物多样性、凋落叶分解速率和主要养分元素释放状况。结果显示：2 mm网孔分解袋土壤动物类群相对密度 年均值为2.67～2.83目•g－1凋落物干重,个体相对密度年均值为22.3～21.77个•g－1凋落物干重,显著 高于0.15 mm网孔分解袋的类群相对密度0.27～0.28目•g－1凋落物干重和个体相对密度2.88～2.77个•g－ 1凋落物干重（p<0.01）,并且0.15 mm网孔分解袋中极少量的动物个体主要为小型类群弹尾目和蜱螨目（ 原生动物、湿生土壤动物线虫不计）,由此我们视2 mm网孔分解袋凋落叶分解由绝大多数土壤动物和其它 土壤生物共同作用,而0.15 mm网孔分解袋基本排除了大中型土壤动物对袋内凋落叶分解的影响。2 mm网 孔分解袋凋落叶物质失重率（71%左右）、分解率指数（1.88～2.44）和主要养分元素释放率明显高于 0.15 mm分解袋（34%～35%,0.48～0.58）。通过比较两种不同网孔分解袋凋落叶失重率和元素释放率的 差异,显示出季节雨林大中型土壤动物群落对凋落叶物质损失的贡献率为年均值46%左右,并使凋落叶C/N 和C/P明显降低,而对不同元素释放率的影响不同,其中对N、S和Ca元素释放率的影响较大,而对K素释放 的影响作用最小。相关分析显示,2 mm网孔分解袋内土壤动物群落类群和个体的相对密度与凋落叶物质残 留率有较好的负相关关系,而群落香农多样性指数与凋落叶分解率指数表现出一定的正相关关系。     

牛山湖两种优势小型鱼类空间分布与沉水植被的关系

运用8种网目规格的成套浮性刺网作为鱼类采样工具,于2005年夏季在长江中游浅水草型湖泊牛山湖进行鱼类定量采样,通过比较不同茂密程度黄丝草生境中的小型鱼类组成、数量和大小结构,探讨此类湖泊小型鱼类的空间分布特征及其与沉水植被的关系.采样期间共捕获13种1124尾鱼,依据其等级丰度和出现频次,鳖和红鳍原鲌为该湖优势上层小型鱼类.在调查的沉水植物生物量范围内,鱼类物种丰富度和Shannon多样性指数与沉水植物生物量之间呈现倒抛物线关系;两种优势小型鱼类的种群丰度均与沉水植物生物量有着显著的线性正相关关系,且其平均个体大小在裸地生境较高、沉水植被茂密区较低,幼鱼更倾向群聚于厚密的黄丝草生境中;其他生境因子(水深和离岸距离)对鳖和红鳍原鲐空间分布的影响不显著.黄丝草植被生境是牛山湖两种优势小型鱼类的重要保护生境,应加强对黄丝草等沉水植被的保护及恢复.     

两种圆柏属植物不同季节显微和超微结构变化与耐寒性的关系

以祁连圆柏和圆柏为材料,研究了圆柏属植物的抗寒性与解剖结构变化,以及淀粉与可溶性糖粉转化的关系.结果表明,祁连圆柏和圆柏叶片的上下表皮细胞外覆盖一层角质膜,叶肉细胞间隙大,形成发达的通气组织.在生长季节,二者叶绿体内均积累了很多淀粉粒,在冷冻休眠季节淀粉粒消失或变小,同时叶片可溶性糖分含量增加,祁连圆柏的可溶性糖分增幅高于圆柏;而休眠季节圆柏叶绿体受到低温伤害,脂质球数目增多,出现脂质小滴,部分叶绿体变形,祁连圆柏类囊体的结构受到影响较小,脂质球数量少,叶绿体形状没有发生明显的变化.因此,祁连圆柏和圆柏抗寒性与发达的通气组织和淀粉粒生长季节的积累有关,在低温胁迫下祁连圆柏叶绿体表现出高的稳定性,通过可溶性糖分的调节力强,耐寒性增强.     

棒络新妇和悦目金蛛拖丝超微结构与力学行为

采用SEM对棒络新妇Nephila clavata腹部向上和向下在水平纱窗上爬行时纺出的拖丝、悦目金蛛Argiope amoena捕食拖丝与垂直向下缓慢纺出的拖丝及其圆网的铆钉丝进行了超微结构观察,采用电子单纤强力仪对棒络新妇拖丝与悦目金蛛圆网铆钉丝进行了力学拉伸试验.结果 表明棒络新妇和悦目金蛛拖丝均呈现出一至多根细丝纤维的多样化超微结构特征,其中悦目金蛛圆网铆钉丝还呈现出"S"形似弹簧的结构.两种蜘蛛丝的力学行为和性能与各自的功能要求相一致.蜘蛛能调节拖丝的超微结构、纤维组成和直径大小以适应其在不同环境条件下对力学性能和功能的瞬时需要.研究结果有助于拓宽和加深人们对蜘蛛丝超微结构、力学性能与生物学功能之间关系的认识和理解.     

Ontogeny of Web-building Behavior in Two Orb-weaving Spiders

Spideis of similar miss but of two different species Araneusdiadematus Cl. and Argiope aurantia L., build webs which havesimilar geometric patterns, but which differ in relative proportionsand thread number. Within species, webs may also differreliably,presumably on a genetic basis. Fine detail of the web undergoeschange throughout the lifetime of the spider, different formale and female; these changes are not simply response to thegrowing weight of the spider. Relatively simple restraints,such as availability of material for thread, result in adaptationsof web-building which may at first appear to be based upon buildingexperience, but which are in fact independent of it.     

Testing the Effects of Biogenic Amines and Alternative Topical Solvent Types on the Behavioral Repertoire of Two Web‐Building Spiders

Investigating the proximate mechanism underlying behavior has long been a primary goal of ethologists. With the recent focus on behavioral correlations (e.g., behavioral syndromes), a fundamental question arises regarding what mechanisms may drive positive relationships between functionally distinct behaviors. Understanding these mechanisms can inform critical questions, such as why distinct behaviors are often correlated, and can also lend insights into how behavioral similarities are conserved across species. Arthropods provide an idea system to study these questions as the biogenic amines, such as octopamine and serotonin, have long been known to mediate a large number of behaviors such as aggression, dominance, escape behavior, and others. Behaviorists have several ways in which they can manipulate these biogenic amines in vivo, including injection, feeding, and topical application. Topical application is potentially an optimal method for manipulating amine concentrations, given that it is minimally invasive and relatively precise. Here, we investigate the role of biogenic amines, octopamine, and serotonin, in mediating a range of similar and often correlated behaviors in two distantly related species of spiders, the western black widow, Latrodectus hesperus, and the funnel‐web spider, Agelenopsis pennsylvanica. Additionally, we investigate the behavioral effects associated with three commonly used carrier solvents: dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and acetone. We demonstrate that biogenic amines are involved both in mediating several behaviors, and also potentially the links between different behaviors. We also show that the same behaviors in different species are not affected by biogenic amines in the same manner, suggesting differences in the underlying neurophysiological mechanisms governing behavior. Furthermore, we discovered large and pervasive effects associated with both carrier solvents, thus calling into question the potential usefulness and interpretability of topical application methods in behavioral research.     

Environmental Predictors of Rotifer Community Structure in Two Types of Small Water Bodies

The species diversity and distribution of rotifers between different habitats (elodeids, helophytes and open water) of 34 field and 31 forest ponds, differing in regard to origin, size, depth, macrophyte cover, overshading and the presence of fish were examined (N = 381). 197 taxa were found in both types of ponds with 32 species being rare, endangered or new to Polish fauna. The species composition and Shannon‐Wiener index distribution reflected heterogeinity of the habitats, while rotifer mean densities revealed a reverse pattern in both types of water bodies. The great variability of limnological features contributed to a lack of significant differences in rotifer abundance between both types of water bodies. Although some rotifers preferred one specific type of water body (forest vs. field), the type of habitat was a much stronger predictor of their distribution, which reflects a necessity to examine ponds in relation to their microhabitats created by various macrophytes. Rotifers revealed a strict division into two groups – of pelagic origin (e.g., Polyarthra vulgaris), which were attributed to the open water and helophytes, and of littoral origin (e.g., Lepadella patella), which were associated with elodeids, biomass of a plant habitat and a lack of fish. The selective choice of the most complex habitat (elodeids) by only littoral species suggests the weak impact of fish in the studied ponds and the most advantageous conditions for littoral rotifers among such a habitat. The first group comprised species characteristic of field ponds, while the second was characteristic of forest ponds. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Adeno-Associated Virus Small Rep Proteins Are Modified with at Least Two Types of Polyubiquitination

Adeno-associated virus (AAV) type 2 and 5 proteins Rep52 and Rep40 were polyubiquitinated during AAV-adenovirus type 5 (Ad5) coinfection and during transient transfection in either the presence or absence of Ad5 E4orf6 and E1b-55k. Polyubiquitination of small Rep proteins via lysine 48 (K48) linkages, normally associated with targeting of proteins for proteasomal degradation, was detected only in the presence of E4orf6. The small Rep proteins were ubiquitinated via lysine 63 (K63) following transfection in either the presence or absence of E4orf6 or following coinfection with Ad5. E4orf6/E1b-55k-dependent K48-specific polyubiquitination of small Rep proteins could be inhibited using small interfering RNA (siRNA) to cullin 5.Together, adenovirus type 5 (Ad5) early gene products E1a, E1b-55k, E2a, E4orf6, and virus-associated (VA) RNA can support efficient replication of adeno-associated virus (AAV) (4, 31). E4orf6 and E1b-55k are known to interact with cellular cullin 5 (cul5), elongins B and C, and the ring box protein Rbx1 to form an E3 ubiquitin ligase complex that specifically targets a small population of cellular proteins for degradation by the proteasome (1, 7, 21, 22, 24, 27). This property has been implicated in a number of functions presumed to be required for both Ad and AAV replication (3, 8-10, 17, 23, 24, 34, 35).Previously, only p53, Mre11, DNA ligase IV, and integrin α3 had been shown to be substrates of the Ad5 E3 ubiquitin ligase complex (1, 7, 21, 22, 24, 27); however, we have recently shown (16, 17) that the small Rep proteins and capsid proteins of AAV5 are also degraded in the presence of Ad E4orf6 and E1b-55k in a proteasome-dependent manner. These proteins were restored to levels required during infection by the action of VA RNA (17). The targeting for degradation of AAV5 protein by the E4orf6/E1b-55k E3 ubiquitin ligase complex required functional BC-box motifs in E4orf6 and could be inhibited by depletion of the scaffolding protein cullin 5 using directed small interfering RNA (siRNA) (16). In addition, the degradation of AAV5 protein was partially prevented by overexpression of pUBR7, a plasmid that generates a dominant-negative ubiquitin (16). The role this targeted degradation plays in the life cycle of AAV has not yet been clarified; however, E4orf6 mutants that cannot function in this regard do not support AAV replication as well as wild-type E4orf6 (R. Nayak and D. J. Pintel, unpublished data). Degradation of Mre11 by the Ad5 E3 ligase has also been implicated in allowing efficient Ad5 and AAV replication (24). Ubiquitination of AAV Rep proteins during viral infection, however, has not previously been reported.