腹毛目纤毛虫大尾柱虫腹皮层纤毛器基部微管的荧光标记

应用荧光紫杉醇直接荧光标记,显示腹毛目纤毛虫大尾柱虫Urostyla grandis腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左、右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成.其中,口围带小膜托架及其相联系的肋壁微管和波动膜基体托架,额棘毛基部前纵微管束、后纵微管束及横棘毛基部前纵微管束,中腹棘毛及左、右缘棘毛基部前纵微管束、后纵微管束和横微管束,是该纤毛虫皮层纤毛器基部的主要附属微管.据结果推测,尽管腹毛目纤毛虫的纤毛器基部微管具有相同的结构成分,但其结构的组成、分化特征、定位和定向、发达程度等均有差异.所得结果为进一步说明纤毛虫细胞皮层纤毛器的形态及其微管建构的多样性提供了新的证据资料.     

新伪尾柱虫腹皮层纤毛器微管胞器的形态和形态发生

应用荧光紫杉醇直接荧光标记法显示,腹毛目纤毛虫新伪尾柱虫(Pseudourostyla nova)腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管及纤毛器基部附属微管组成.口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"Λ"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一;缘棘毛基部含前纵微管束、后纵微管束.同时,对新伪尾柱虫纤毛器微管胞器的形态发生和生理改组过程进行了详细的追踪研究,并对细胞皮层的额腹棘毛定位及组成特征进行了补充报道.此外,发现形态发生末期新纤毛器微管形成时,残存部分老额棘毛、横棘毛和缘棘毛,此后老结构逐渐被吸收.结果表明,新伪尾柱虫的纤毛器基部微管具有其种的特异性,新纤毛器微管分化过程中老结构可能具有定位和物质贡献作用.     

魏氏拟尾柱虫腹皮层纤毛器微管胞器的形态及形态发生

应用荧光紫杉醇直接荧光标记和抗α-微管蛋白抗体免疫荧光标记显示,魏氏拟尾柱虫(Paraurostyla weissei)腹面皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成。其中口围带基部微管包括小膜托架、小膜附属微管;额腹横棘毛和左右缘棘毛基部附属微管包括前纵微管束、后纵微管束和横微管束,它们由各自的纤毛器基部向皮层细胞质不同方向发射,形成腹皮层表面下微管网。结果表明,魏氏拟尾柱虫的纤毛器骨架、纤毛器附属结构也是一类以微管蛋白为基本成分的微管胞器,其中缘棘毛基部附属微管具有不同于其他纤毛虫(例如棘尾虫)中所观察到的同种微管胞器的建构特征。形态发生中,前仔虫口围带在老结构位置形成,其结构建成与部分老口围带的更新有关;老缘棘毛的结构物质对新的左、右缘棘毛的发生可能具有定位作用及物质贡献,但此后新的左、右缘棘毛列分别在老缘棘毛的右侧形成,而并非是在老缘棘毛位置分化的。在有些细胞中,新的左缘棘毛左侧另有一列棘毛,这可能是形态发生中老的左缘棘毛退化不完全产生的。     

腹毛目纤毛虫鬃棘尾虫纤毛器基部微管的荧光标记

腹毛目纤毛虫鬃棘尾虫的纤毛器微管骨架由口围带、波动膜、额腹横尾棘毛、左右缘棘毛和背触毛等纤毛器微管和纤毛器基部附属微管等组成,其中口围带基部含小膜托架、小膜后微管、小膜托架微管及小膜托架间的倒"V"形微管连接;波动膜基部形成微管骨架网;额腹横棘毛和左、右缘棘毛基部含前纵微管束、后纵微管束和横微管束,但不同位置的棘毛基部微管发达程度不一样;背触毛基部以纤毛基体为中心向前、后皮层发出前纵微管和后纵微管,形成背皮层微管网.     

拟翁口虫形态学及形态发生学现象的初步研究

应用荧光紫杉醇直接荧光标记方法显示了一种腹毛类纤毛虫拟翁口虫(Onychodromopsis sp.)腹皮层纤毛器微管胞器及形态发生,根据该纤毛虫的皮层纤毛模式和纤毛器基部微管的形态,将其归为侧毛虫科(Pleurotrichidae)拟翁口虫属(Onychodromopsis);并据后仔虫口原基的发生、左右缘棘毛原基的...     

原生动物贻贝棘尾虫微管胞器的荧光标记与显示

采用FLUTAX直接荧光标记和抗α微管蛋白抗体的间接免疫荧光标记显示,原生动物贻贝棘尾虫(Stylonychia mytilus)细胞微管胞器由口围带、波动膜、额腹横棘毛、左右缘棘毛、背纤毛等纤毛器微管骨架、纤毛器基部附属微管和其他皮层微管骨架组成。纤毛器微管骨架和基部附属微管按皮层纤毛模式定位;皮层左、右侧微管带和领肋壁微管等其他皮层微管构成细胞特定位置的皮层微管骨架,并可能为具有背腹分化的腹毛目纤毛虫所特有,对维持细胞背腹面的形态、支持附近纤毛器(如左、右缘棘毛)的运动起作用。本文较完整地阐述了其细胞骨架的三维构形,对于深入了解纤毛虫细胞微管骨架的结构和分布特征,进一步揭示微管类胞器的功能是有意义的。     

冠突伪尾柱虫的腹皮层纤毛器微管胞器及其形态发生

应用荧光紫杉醇直接荧光标记和抗α-微管蛋白抗体免疫荧光标记方法,显示冠突伪尾柱虫腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成。口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"∧"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一,其中两列中腹棘毛基部微管紧密联系成一条粗绳索样结构,且左、右中腹棘毛基部的横微管束定向相反;左、右缘棘毛基部含前纵微管束、后纵微管束和横微管束,其中横微管束不发达。与目前已知的腹毛目纤毛虫例如贻贝棘尾虫、魏氏拟尾柱虫的纤毛器基部微管相比较,冠突伪尾柱虫腹皮层纤毛器基部微管除具有腹毛目纤毛虫纤毛器基部微管的基本特征外,也具有一些特殊的组成模式。皮层纤毛器微管形态发生中,前仔虫口围带并非全部是由老口围带更新而来的,其老口围带只有翻领部发生更新,且翻领部与领部接续处有一小段老的翻领部小膜保留,领部的小膜保留,结果其领部小膜、接续处保留的小膜与更新的翻领部小膜三部分共同组成前仔虫的新口围带。在后仔虫口原基发生的位置,其邻近的老横棘毛没有变化,此时老的横棘毛或许能起到"参照点"或定位作用;各类纤毛器发生、分化过程中,处于非原基区的老额棘毛、横棘毛及左右缘棘毛在较长时间内均未见明显的变化。它们可能是在新结构形成时仍然起到运动作用继而逐渐失去功能而退化瓦解的。     

华美游仆虫细胞微管胞器的直接荧光和免疫荧光标记

应用直接荧光和免疫荧光标记显示,腹毛目纤毛虫华美游仆虫(Euplotes elegans)细胞微管胞器由口围带、波动膜、额腹横棘毛、缘棘毛、尾棘毛、背触毛等纤毛器微管以及纤毛器基部附属微管和非纤毛区皮层微管骨架组成.其中,口围带基部含有小膜托架、小膜附属微管,波动膜基部含有波动膜托架,额腹横棘毛基部含有前纵微管束、后纵微管束、横微管束或放射微管柬,左缘棘毛和尾棘毛基部微管束分化不明显,背纤毛基部含有攻瑰花状的基体周围骨架,这些微管结构与细胞背腹面皮层纵微管与横微管网一起组织成该类纤毛虫的主要皮层细胞骨架.结果表明,游仆虫皮层细胞骨架是以微管为主要成分构建而成的,并且其棘毛基部微管的组成具有与其他类纤毛虫不同的特征;游仆虫间期细胞及形态发生时期纤毛基体或纤毛原基中存在中心蛋白,其可能与纤毛基体结构的维持及基体发生过程中微管的组装有关.     

草丛土毛虫皮层纤毛器的微管胞器研究

本文应用FLUTAX直接荧光标记和抗α-微管蛋白抗体免疫荧光标记．显示了土壤纤毛虫草丛土毛虫（Territricha stramenticola）的皮层纤毛器微管胞器．其中纤毛器基部微管按口围带、波动膜、额腹横棘毛、左右缘棘毛、背触毛等纤毛器图式分布和定位,口围带和波动膜基部含小膜微管托架、小膜附属微管和波动膜微管骨架网;额腹横棘毛基部含前纵微管束、后纵微管束和横微管束：左、右缘棘毛基部含前纵微管束、后纵微管束、横微管束及后微管芽;背触毛基部含前纵微管束、后纵微管柬。横棘毛基部含有较发达的横微管束,缘棘毛基部含后微管芽及其横微管束的定位可能具有本种纤毛虫细胞的特异性。纤毛器微管胞器在细胞表膜下分化形成的基部微管及其微管层使细胞的运动纤毛器与强固的微管骨架结构网相联系．其微管胞器的建构可能是细胞对土壤生存环境的一种适应．是细胞运动胞器的功能活动与环境相互作用的结果。形态发生中,老口围带微管是逐步进行更新的：老棘毛微管胞器对新结构的发生和形成具有定位和物质贡献的作用．并且老结构在新结构分化和成熟期间也经历了行使相应的生理功能及逐渐退化和失去功能的过程．     

阔口尖毛虫皮层纤毛器微管在不同生理条件下的分化

应用激光扫描共聚焦显微术,显示腹毛类纤毛虫阔口尖毛虫(Oxytricha platystoma)无性生殖过程中,新的口围带、波动膜、额腹横棘毛、左右缘棘毛微管先后分化,老纤毛器微管去分化,细胞分裂产生各含一套纤毛器微管的前、后两仔虫;生理改组过程中,口围带、波动膜、额腹横棘毛、左右缘棘毛微管发生去分化和再分化,细胞皮层微管胞器更新形成含一套纤毛器微管的新细胞。结果表明阔口尖毛虫在无性生殖和生理改组这两种不同的生理条件下,其纤毛器微管结构的形成或更新可能具有相同的细胞调控机制,形态发生中老纤毛器结构可能对新结构的发生和发育具有诱导定位和物质贡献的作用。     

阔口尖毛虫纤毛器微管的激光共聚焦显微镜观察

应用激光扫描共聚焦显微术显示经荧光紫杉醇标记的阔口尖毛虫(Oxytricha platystoma)口围带、波动膜、额腹横棘毛、左右缘棘毛等纤毛器的微管类细胞骨架.其口围带基部含小膜托架、托架间连接微管和小膜基部微管束,波动膜基部含发达的微管骨架网,口围带和波动膜后端的汇合处含有口底托架及口后微管束,额腹横棘毛和左、右...     

The Structure and Morphogenesis of the Ventral Ciliature in Paraurostyla hymenophora*

SYNOPSIS. The structure and morphogenesis of the ventral ciliature of Paraurostyla hymenophora (Stokes) are described. The oral primordium apparently originates in association with transverse cirrus #6, from which it migrates anteriorly simultaneous with kinetosomal proliferation. The primordium eventually forms an elongate ciliary field from which the future opisthe's fronto-ventro-transverse (FVT) and undulating membrane primordial fields arise. Concomitantly, the future proter's FVT primordial field is initiated by the disaggregation of frontal cirri #4, #5, and #6. Primordia then develop simultaneously within marginal and ventral cirral rows by a disaggregation of cirri within the respective rows, and do not give rise to new cirri until the FVT fields complete segregation into discrete cirri. Near the completion of cirral production from the FVT primordia, each ventral cirral primordium (VCP) forms the 2 rightmost transverse cirri. Segregation of new cirri within the marginal cirral primordia and VCP then occurs, eventually replacing all old cirri within their respective marginal and ventral cirral rows. At the end of cortical morphogenesis, all old ciliary organelles, with the exception of the adoral zone of membranelles, are either reorganized or replaced. These results suggest an evolutionary affinity between the ventral and marginal cirral rows and raise questions about the control of the developmental competence of individual primordia.     

Mycobiota associated with the ambrosia beetle Scolytodes unipunctatus (Coleoptera: Curculionidae, Scolytinae)

Ambrosia beetles (Coleoptera: Scolytinae) are associated with strictly entomochoric and mutualistic fungi. We studied the mycobiota associated with Scolytodes unipunctatus, ambrosia beetles that infest Cecropia trees in Central America. Isolates were characterized using morphology and rDNA sequences (ITS region, LSU, and SSU rDNA). Four species are described here: Raffaelea scolytodis sp. nov. (Ophiostomatales), Gondwanamyces scolytodis sp. nov., Custingophora cecropiae sp. nov., and Graphium sp. (Microascales). The genus Custingophora is emended to include Knoxdaviesia anamorphs of Gondwanamyces based on uniformity of DNA sequences and phenotype.     

核盘菌侵染对拟南芥表皮蜡质结构及化学组成的影响

以野生型拟南芥与蜡质突变体cer1、cer4为试验材料,通过研究核盘菌胁迫对拟南芥茎表皮蜡质结构及组分含量的影响,揭示核盘菌侵染与表皮蜡质的关系。扫描电镜结果显示,野生型拟南芥蜡质晶体以垂直于表面的杆状、块状结构为主;突变体cer1晶体类型以水平的松针状、块状结构为主;突变体cer4蜡质晶体以垂直片层结构为主。核盘菌胁迫下,拟南芥蜡质晶体结构及分布形态发生变化。蜡质层结构在核盘菌胁迫下表现为:杆状、松针状蜡质晶体减少—蜡质晶体熔融—表皮"囊状凸起"—表皮膜层破裂。这些结构变化有利于病菌突破角质层屏障而侵入到植株体内。色质谱分析结果显示:与野生型相比,cer1突变体烷、次级醇、酮类显著减少;cer4突变体表现为一级醇含量减少。接种核盘菌后,野生型拟南芥与蜡质突变体一级醇类显著增加(cer1增加不显著);烷类、次级醇类、酮类含量与蜡质总量均显著减少,表明蜡质前体物质在受到核盘菌胁迫后更多地通过酰基还原途径生成一级醇,从而减少了由脱羰基途径所生成的蜡质组分。核盘菌通过改变表皮蜡质晶体结构与化学组分分泌量来促进侵染。     

Starch grain morphology of the seagrasses Halodule wrightii, Ruppia maritima, Syringodium filiforme, and Thalassia testudinum

Starch grains are a ubiquitous component of plants that have been used in tandem with phytoliths, pollen, and macrofossils to reconstruct past floral diversity. This tool has yet to be fully explored for aquatic plants, specifically seagrasses, which lack phytoliths and are rarely preserved as macrofossils or pollen. If starch grains in seagrasses are morphologically distinct, this method has the potential to improve seagrass identification in the fossil record in such cases where its starch is preserved (e.g. scratches and occlusal surfaces of tooth enamel from seagrass consumers). The goals of this study were twofold: (1) to determine if starch is present in seagrass material and (2) to assess how starch grain morphology differs between different seagrasses.This study focused on four abundant and ecologically distinct seagrasses from the Caribbean: Halodule wrightii, Ruppia maritima, Syringodium filiforme, and Thalassia testudinum. Starch grains were observed in all species except S. filiforme. Grains from H. wrightii are typically observed in side-on orientation, are sub-round to angular, and are fairly small (3-19 μm, end-on). Grains of R. maritima are small spherical grains (4-8 μm) that have a centric hilum and a straight extinction cross with a median angle between the arms of 90°. Grains from T. testudinum are large (9-31 μm, end-on), conical in side-on and round/sub-round in end-on orientation, have a slightly eccentric hilum with an obvious particle, and prominent lamellae.Visual assessment and comparative statistics demonstrate that the morphology of starch grains from T. testudinum, R. maritima, and H. wrightii are significantly different. With more extensive research, there is potential for the positive identification of starch grains from an unknown seagrass. The ability to identify seagrass from starch grains could facilitate the identification of seagrasses in the fossil record and supply information on seagrass evolution and distribution, climate effects on seagrass distribution, and the diets of seagrass consumers.     

Systematics and evolution of the genus Torrubiella (Hypocreales, Ascomycota)

Torrubiella is a genus of arthropod-pathogenic fungi that primarily attacks spiders and scale insects. Based on the morphology of the perithecia, asci, and ascospores, it is classified in Clavicipitaceae s. lat. (Hypocreales), and is considered a close relative of Cordyceps s. 1., which was recently reclassified into three families (Clavicipitaceae s. str., Cordycipitaceae, Ophiocordycipitaceae) and four genera (Cordyceps s. str, Elaphocordyceps, Metacordyceps, and Ophiocordyceps). Torrubiella is distinguished morphologically from Cordyceps s. lat. mainly by the production of superficial perithecia and the absence of a well-developed stipitate stroma. To test and refine evolutionary hypotheses regarding the placement of Torrubiella and its relationship to Cordyceps s. lat., a multi-gene phylogeny was constructed by conducting ML and Bayesian analyses. The monophyly of Torrubiella was rejected by these analyses with species of the genus present in Clavicipitaceae, Cordycipitaceae, and Ophiocordycipitaceae, and often intermixed among species of Cordyceps s. lat. The morphological characters traditionally used to define the genus are, therefore, not phylogenetically informative, with the stipitate stromata being gained and/or lost several times among clavicipitaceous fungi. Two new genera (Conoideocrella, Orbiocrella) are proposed to accommodate two separate lineages of torrubielloid fungi in the Clavicipitaceae s. str. In addition, one species is reclassified in Cordyceps s. str. and three are reclassified in Ophiocordyceps. The phylogenetic importance of anamorphic genera, host affiliation, and stipitate stromata is discussed.     

Pollen morphology of Chinese Curcuma L. and Boesenbergia Kuntz (Zingiberaceae): Taxonomic implications

In order to find new non-molecular evidence to support the phylogenetic and taxonomic position, pollen grains of 20 populations of 16 species of Chinese Curcuma L. and Boesenbergia Kuntz (Zingiberaceae) were investigated under SEM and TEM. The pollen grains are spherical and ovoid, nonaperturate. The pollen wall is composed of a very thin exine and a thick intine. The exine is psilate or echinate. The intine consists of two layers, i.e., a thick, channeled layer (exintine) and an inner homogenous layer (endintine). The results reveal morphological congruence between the pollen grains of species of Curcuma, which according to DNA sequence data appears to be a polyphyletic genus. However the uniform pollen morphology in Curcuma provides no evidence to divide this genus into separate taxonomic entities. Our results on pollen morphology also do not provide any additional evidence to either unite or segregate Boesenbergia albomaculata and Curcumorpha longiflora in the same genus and demonstrate that more taxonomic data on the genus Boesenbergia and its relatives are needed before a final decision can be made.