【作者】 周素娟；

【导师】 顾福康；

【作者基本信息】 华东师范大学 ， 动物学， 2008， 硕士

【摘要】 以原生动物作为材料,探索真核细胞微管胞器的结构、功能及其细胞模式形成机理已成为热点。以往的研究都是以较为低等的类群为研究对象,像体纤毛分散排布的较低等的草履虫(Paramecium)、四膜虫(Tetrahymena),而以较为高等的皮层纤毛结构排列不同的腹毛目纤毛虫为材料研究细胞微管胞器的建构特征及其在形态发生中的特征,对进一步揭示出细胞内部不同水平调控机理、微管组织中心基体微管的装配具有很大的意义。本文以冠突伪尾柱虫(Pseudourostyla cristata),一种游仆虫(Euplote),一种急纤虫(Tachysoma)的纤毛器微管胞器为对象,采用荧光紫杉醇(fluorescence taxoid,FLUTAX)直接荧光染色和抗α-微管蛋白抗体间接免疫荧光方法,研究分析在进化过程中不同类群微管成分、微管结构、形态发生的差异,探索不同属之间微管胞器定位定向和形态发生的规律,结果如下:1微管胞器定位定向共同点1)三类纤毛虫腹面的纤毛器微管胞器均由口围带、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。2)三类纤毛虫腹面的纤毛器基部均含有三种基本的微管成分:前纵微管束、后纵微管束和横微管束。3)口围带翻领部小膜托架均呈阶梯状排列,领部小膜托架呈“∧”形,可能为一稳定进化结构。4)横棘毛的前纵微管束表现出向前伸展聚合的特性。2微管胞器定位定向不同点1)横微管束在不同类群中的定位定向有很大差异。其中,冠突伪尾柱虫左右缘棘毛基部的横微管束不发达定位在棘毛基部左后端,游仆虫内的横微管束垂直于横棘毛的五根发达的前纵微管束,急纤虫左右缘棘毛基部的横微管束均向细胞左侧伸展。2)各类群均含有特殊的微管结构。其中冠突伪尾柱虫2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。游仆虫横棘毛的五根发达的前纵微管束从细胞后端横棘毛的位置向前端发射,几乎贯穿于整个细胞;腹面棘毛基部前纵微管束和后纵微管束分别由棘毛基部向左前方和向右后成钝角伸展;而周围微管束一致向左呈五指分散状伸展。急纤虫左右缘棘毛基部的横微管束伸展方向不在一个平面,而是从细胞前部至后,由浅入深。3形态发生共同点1)几类纤毛虫的形态发生均有严格的时序性,按照口围带-波动膜-额腹横棘毛-左右缘棘毛的顺序进行。2)老的棘毛均有不同程度的更新,但有部分老的棘毛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。4形态发生不同点1)口围带的更新:冠突伪尾柱虫形态发生中,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。游仆虫老口围带并非遗传而是完全更新的,但口围带的更新速度大于瓦解速度,很难捕捉到老口围带瓦解的现象。急纤虫老口围带仅在翻领部原位进行了更新,且更新与新口的发生几乎是同步进行。2)新口的发生位置:冠突伪尾柱虫后仔虫口原基发生于腹棘毛的终止位置左边、横棘毛的附近,且老的横棘毛没有变化或许能起到“参照点”或定位作用。游仆虫口原基发生于深皮层。急纤虫后仔虫口围带原基的起始位置在老口围带的近左下方,这与尖毛科其他种类有差异。更多还原

【Abstract】 The ciliates are ideal material to study on the structure and fuction of microtubular organelles of Eukaryotic cell.The former study focused on Paramecium and Tetrahymena which is low in evolution.Studies on Hypotrichous ciliates which are high in evolution will give more explanation for regulation of cell and microtubular organization.We chose Pseudourostyla cristata,Euplote,Tachysoma with fluorescent labeling of fluorescent taxoid and anti-αtubulin antibody as the typical species to study the rules of orientation and morphogenesis of microtubular organelles.The results were as the following.1 Similar characters of microtubular strcture1)Microtubular organelles in all the three kinds of ciliates included adoral zone of membranelles(AZM),undulating membranes(UM),frontal-midventral-transverse cirri(FVTC), left & fight marginal cirri(L- & RMC)and the base-associated microtubules of these ciliatures.2)The base-associated microtubules consisted of anterior longitudinal microtubules(ALM), posterior longitudinal microtubules(PLM),transverse microtubules(TM).3)In the basal part of the AZM of the three,membranelle brackets were ladder-like. The membranelle brackets located in the collar portion are connected with∧-shaped microtubules.4)The ALM under the base of TC presented the character of aggregation.2 Different characters of microtubular strcture1)The location and orientation of TM varied in different species.L- & RMC base microtubules which located at the left-end of the base of cirri in Pseudourostyla cristata were not well-developed.TM in Euplote was perpendicular to the five welldeveloped ALM.TM under the L- & RMC base in Tachysoma extended to the left.2)Each species contained different kinds of microtubular structures.The base-associated microtubules of the two rows of ventral cirri(VC)in Pseudourostyla assemble close to form a cord-like structure and TM of the two rows of VC extend in opposite directions.TC base five ALM in Euplote extended from the back-end to the front-end of the cell.These five ALM almost ran longitudinally through the whole cell. ALM and PLM in Euplote extended from the base of cirri to the left anterior and right posterior separately in triangular way,and RM extended as stretched-five-finger to the left consistently.MC base TM extended in the cortex gradually from the surface in the front-end to the deep in the back-end.3 Similar characters of Morphogenesis1)The process of the morphogenesis were sequential in all the three.That is AZM-UM-FVTC-MC.2)The old cirri was renewed to different extent.Part of the old cirri persisted unchanged for a long time may help to move when the new ciliatures formed,then declined functionally and degenerated in the end.4 Different characters of Morphogenesis1)Renewal of the old AZM:During the process of the morphogenesis of Pseudourostyla cristata in the ventral cortex,AZM of proter was generated from the renewed lapel part of AZM(AZM-L),the old AZM-C as well as the conserved minor intersection between AZM-L and AZM-C.During the process of the morphogenesis of Euplote in the ventral cortex,the renewal of the old AZM occurred much faster than the degeneration of it.So it was so harder to get the picture of degeneration of the old AZM.The old AZM was wholely renewed eventually.During the process of the morphogenesis of Tachysoma,the whole old AZM was renewed.2)The location where oral primordium(OP)started:OP of opisthe in Pseudourostyla cristata began to occur at the left-end of VC and near TC which didn’t degenerate might play a role of "reference point" or "orientation".It can finally support the theory that OP in Euplote occured in the deep cortex.During the process of the morphogenesis of Tachysoma,OP of opisthe started nearby left- posterior of the old AZM which were different from the other species in Tachysoma.更多还原